Fix es.json translation-catalog parity with en.json

test_every_language_mirrors_the_english_catalog was failing on main
for es (PR #246) independent of this branch. Beyond the 32 keys en.json
gained since #246 merged (the AC/fan preset_mode and fan_mode state
blocks, and the new EHS/zone/auto-clean keys), the file had accumulated
several pre-existing bugs that also broke topology parity:

- climate.airconditioner and fan.air_purifier_fan carried a stray
  "name" key that doesn't exist in en.json's catalog for either (both
  entities are unnamed in code); removed, and their real
  state_attributes blocks added.
- select.buzzer_sound and select.finish_sound were keyed by literal
  on-wire device codes (Volume_Off/Low/Med/High, Finish Sound_1/2/3)
  instead of en.json's actual off/on states -- dead translations, never
  resolved at runtime. finish_sound's values were also unrelated song
  titles, not sound-toggle labels. Replaced both with real off/on
  entries.
- select.dryer_cycle_table_03 had codes 1c/1d/1e (Shirts/Towels/Outdoor)
  rotated by one slot, so a Shirts cycle displayed "Toallas"; realigned
  to the correct codes and added the 2 missing ones (2b, 4c).
- select.washer_cycle_table_02 carried 4 stray codes (06/08/74/A0) not
  present in en.json's table at all, duplicating already-correct
  translations under codes this device never reports; removed.

tests/test_translations.py now passes for every language, and the full
suite is green (1121 passed).

README.md

@@ -137,7 +137,7 @@ custom_components/localthings/
   diagnostics.py           Redacted diagnostics download (device state + coverage metadata)
   const.py                 Domain, config keys, probe ports
   entity.py                Base entity wiring capability registry -> HA entity
-  sensor.py / binary_sensor.py / switch.py / number.py / select.py / button.py / time.py / fan.py / climate.py
+  sensor.py / binary_sensor.py / switch.py / number.py / select.py / button.py / time.py / fan.py / climate.py / water_heater.py
                             One module per HA platform
   catalog.py               Reads the shipped translation catalog (which keys/states exist)
   translations/            Config-flow copy + entity name/state translations, one file per

custom_components/localthings/const.py

@@ -2,7 +2,7 @@ DOMAIN = "localthings"
 
 PLATFORMS = [
     "sensor", "binary_sensor", "switch", "number", "select", "button",
-    "time", "climate", "fan",
+    "time", "climate", "fan", "water_heater",
 ]
 
 CONF_HOST         = "host"

custom_components/localthings/observe.py

@@ -73,6 +73,9 @@ class ObserveManager:
         self.subscribed_hrefs: set[str] = set()
         self._notified: set[str] = set()
         self._last_notify_ts: float | None = None
+        # Wakes try_enter_observe_mode's grace wait early once enough hrefs
+        # have notified. Guards only `_notified` mutations + the `wait_for`.
+        self._notify_cond = threading.Condition()
         self.fallback_hrefs: set[str] = set()
         self._refresh_task: ObserveRefreshTask | None = None
         self._refresh_stop: threading.Event | None = None
@@ -147,8 +150,10 @@ class ObserveManager:
             return
         if not isinstance(rep, dict):
             return
-        self._notified.add(href)
-        self._last_notify_ts = time.monotonic()
+        with self._notify_cond:
+            self._notified.add(href)
+            self._last_notify_ts = time.monotonic()
+            self._notify_cond.notify_all()
         self.log.debug("observe notify: %s", href)
         self.apply(href, rep, source='observe')
 
@@ -172,10 +177,12 @@ class ObserveManager:
         grace_period_s: float = GRACE_PERIOD_S,
         success_fraction: float = SUCCESS_FRACTION,
     ) -> bool:
-        """Blocking — subscribes to every href then sleeps for the whole
-        grace period. Caller must run this in an executor, never on the
+        """Blocking — subscribes to every href then waits up to
+        `grace_period_s`, returning early once `success_fraction` of hrefs
+        have notified. Caller must run this in an executor, never on the
         event loop."""
-        self._notified.clear()
+        with self._notify_cond:
+            self._notified.clear()
         subscribed: set[str] = set()
         for href in hrefs:
             segs = [s for s in href.strip('/').split('/') if s]
@@ -190,10 +197,18 @@ class ObserveManager:
             self.subscribed_hrefs = set()
             return False
 
-        time.sleep(grace_period_s)
+        def _fraction_reached() -> bool:
+            return (
+                len(set(self._notified) & subscribed) / len(subscribed)
+                >= success_fraction
+            )
 
-        fraction = len(set(self._notified) & subscribed) / len(subscribed)
-        if fraction >= success_fraction:
+        with self._notify_cond:
+            reached = self._notify_cond.wait_for(
+                _fraction_reached, timeout=grace_period_s,
+            )
+
+        if reached:
             self.subscribed_hrefs = subscribed
             self._set_mode(MODE_OBSERVE)
             self.start_refresh_task(session)

custom_components/localthings/registry/by_type/__init__.py

@@ -5,7 +5,7 @@ from typing import Optional, Sequence
 from ._base import DeviceRegistry
 from . import (
     air_dresser, air_monitor, air_purifier, airconditioner, cooktop,
-    dehumidifier, dishwasher, dryer, induction_cooktop, microwave, oven,
+    dehumidifier, dishwasher, dryer, ehs, induction_cooktop, microwave, oven,
     range as _range, range_hood, refrigerator, vacuum_station, washer,
     water_purifier,
 )
@@ -27,6 +27,7 @@ _REGISTRY_BY_KEY: dict[str, DeviceRegistry] = {
     'dehumidifier': dehumidifier.REGISTRY,
     'dishwasher': dishwasher.REGISTRY,
     'dryer': dryer.REGISTRY,
+    'ehs': ehs.REGISTRY,
     'induction_cooktop': induction_cooktop.REGISTRY,
     'microwave': microwave.REGISTRY,
     'oven': oven.REGISTRY,
@@ -87,6 +88,10 @@ _BOARD_TOKEN_TO_KEY: dict[str, str] = {
     'CAC': 'airconditioner',        # issue #191 -- TP1X_DA-AC-CAC-01001_0000
     'ARA': 'airconditioner',
     'DHM': 'dehumidifier',          # issue #88 -- target humidity, no climate
+    'EHS': 'ehs',                   # Eco Heating System air-to-water heat pump --
+                                     # zone1 space heating/cooling + dhw domestic
+                                     # hot water, its own /mode/*/vs/0 and
+                                     # /temperatures/*/vs/0 resource shapes
     'TVTL': 'air_purifier',         # issue #56 (ARTIK051)
     'VTWW': 'air_purifier',         # issue #151 (BESPOKE Cube Air)
     'AVT': 'air_purifier',          # issue #190 -- AVT-WW-TP1-23-AXX500, a
@@ -214,6 +219,16 @@ def _consumer_model_key(description: str) -> Optional[str]:
 # device-type vocabulary (used for categories with no `oic.d.*` equivalent),
 # same prefix convention as the `x.com.samsung.da.*` resource fields
 # elsewhere in this codebase.
+#
+# `oic.d.cooktop` is deliberately absent, and is the one measured type left out.
+# A TP1X_DA-KS-COOKTOP induction reports it, but `cooktop` and
+# `induction_cooktop` are two unrelated registries that happen to share the
+# English word (see by_type/cooktop.py's docstring: the NA9300K gas family keeps
+# burner state in /mode/vs/0's options array, a completely different OCF
+# surface). The OCF type does not distinguish them, so mapping it to either key
+# would silently misroute the other -- and as the *primary* signal it would
+# override a `COOKTOP`/`CT` board token that had it right. Same reasoning as
+# `oic.d.robotcleaner` above: no unambiguous key to point at, so no row.
 _OIC_TYPE_TO_KEY: dict[str, str] = {
     'oic.d.airconditioner': 'airconditioner',
     'oic.d.airpurifier': 'air_purifier',
@@ -223,6 +238,7 @@ _OIC_TYPE_TO_KEY: dict[str, str] = {
     'oic.d.refrigerator': 'refrigerator',
     'oic.d.washer': 'washer',
     'x.com.st.d.airqualitysensor': 'air_monitor',
+    'x.com.st.d.hood': 'range_hood',              # AHD-WW-TP1-22-COMMON
     'x.com.st.d.stickcleaner': 'vacuum_station',
     'x.com.st.d.steamcloset': 'air_dresser',
 }
@@ -285,13 +301,16 @@ def for_device_by_model(model_num: str, description: str) -> Optional[DeviceRegi
 def for_device_by_resources(resources: dict[str, dict]) -> Optional[DeviceRegistry]:
     """Detect a device family from a distinctive local-resource signature.
 
-    For boards that ship no ``/information/vs/0`` at all, leaving
-    `for_device_by_model` nothing to read. Some newer cooktops are the
+    This runs first as an override path for non-standard devices, not because
+    resource signatures are inherently more trustworthy than OIC/model
+    metadata. It also types boards that ship no ``/information/vs/0`` at all,
+    leaving `for_device_by_model` nothing to read. Some newer cooktops are the
     original case: their mode resource still identifies them, carrying a
     DeviceType option and multiple per-burner OperationState options.
 
     Require two independent shapes for every signature here, never one, so
-    an unrelated family's ``/mode/vs/0`` isn't misclassified.
+    putting this ahead of OIC/model metadata cannot let a common resource
+    misclassify an unrelated family.
     """
     mode = resources.get('/mode/vs/0', {})
     options = mode.get('x.com.samsung.da.options') or ()
@@ -314,9 +333,14 @@ def for_device_by_resources(resources: dict[str, dict]) -> Optional[DeviceRegist
     # (issue #74's NE63B8411SS, issue #172's ME8000T -- the resource is simply
     # absent from the dump, not just empty) can't be matched via
     # for_device_by_model's modelNum tokens either. Mode vocabulary alongside
-    # the oven cavity resource (/oven/vs/0) is a safe signature.
+    # the oven cavity resource (/oven/vs/0) is a safe two-resource signature;
+    # it also corrects Qooker's generic oic.d.oven / OVEN metadata (issue
+    # PR #225) when resource detection runs before metadata.
     supported_modes = mode.get('x.com.samsung.da.supportedModes') or ()
-    if '/oven/vs/0' in resources:
+    if not isinstance(supported_modes, (list, tuple)):
+        supported_modes = ()
+    cavity = resources.get('/oven/vs/0')
+    if isinstance(cavity, dict):
         if any(
             m in supported_modes
             for m in ('MicroWave', 'MicroWaveGrill', 'MicroWaveConvection')
@@ -338,13 +362,13 @@ def resolve(
     flow's probe and the golden-regression harness all call this, so the
     order can't drift between what ships and what the tests assert.
 
-    `device_types` (/oic/d's `rt`, read separately from the /device/0 dump --
-    see registry/identity.py) is the primary signal when present: the device
-    naming its own type beats parsing board part numbers. Falls back to model
-    strings (`for_device_by_model`), then a distinctive resource signature
-    (`for_device_by_resources`) for boards that report no /information/vs/0
-    at all -- both unchanged from before /oic/d was ever consulted, since most
-    hardware still doesn't populate it usefully.
+    Distinctive resource signatures run first because they describe the live
+    capability surface a registry must bind. They are deliberately strict in
+    `for_device_by_resources`: each requires multiple independent details, so
+    this can correct misleading metadata (Qooker's generic ``oic.d.oven``)
+    without a common href overriding an unrelated family. When no signature
+    matches, `/oic/d`'s `rt` (read separately from the /device/0 dump -- see
+    registry/identity.py) wins over model-string parsing.
 
     `/otninformation/vs/0`'s oneUiVersion is deliberately not consulted. It
     reads like the obvious signal -- the device naming its own type, e.g.
@@ -355,10 +379,10 @@ def resolve(
     """
     info = resources.get('/information/vs/0', {})
     return (
-        for_device_by_oic_type(device_types)
+        for_device_by_resources(resources)
+        or for_device_by_oic_type(device_types)
         or for_device_by_model(
             info.get('x.com.samsung.da.modelNum', ''),
             info.get('x.com.samsung.da.description', ''),
         )
-        or for_device_by_resources(resources)
     )

custom_components/localthings/registry/by_type/ehs.py

@@ -0,0 +1,29 @@
+"""EHS (Eco Heating System) air-to-water heat pump device registry
+(Samsung TP1X_DA_AC_EHS-class).
+
+Shares the DA_AC_ board prefix with the room-AC family in
+airconditioner.py, but its /mode/*/vs/0 and /temperatures/*/vs/0 resources
+are its own shape (two independent loops: zone1 space heating/cooling and
+dhw domestic hot water), not airconditioner.py's HREF_MODE/HREF_TEMP* OCF
+pattern -- so nothing from that module is reused here except MUTE_ONCE,
+whose /option/muteonce/vs/0 field shape (`muteonce`) is identical on this
+family's dump.
+"""
+from ..capabilities import airconditioner, common, ehs, ignored
+from ._base import DeviceRegistry, _build
+
+REGISTRY = DeviceRegistry(
+    name='ehs',
+    capabilities=_build([
+        *ignored.IGNORED,
+        *common.UNIVERSAL,
+        airconditioner.MUTE_ONCE,
+        ehs.ZONE_POWER,
+        ehs.ZONE_MODE,
+        ehs.ZONE_TEMPERATURE,
+        ehs.DHW,
+        *ehs.DHW_CONSUMED,
+        ehs.AWAY_MODE,
+        *ehs.COVERAGE,
+    ]),
+)

custom_components/localthings/registry/capabilities/airconditioner.py

@@ -596,15 +596,109 @@ CLIMATE = Capability(
                    unit='°C', icon='mdi:home-thermometer-outline'),
         # Filter time in tenths of an hour: the token read 1710 while the official
         # Samsung app displayed "171 hours 0 minutes" for the filter on the same
-        # unit, and the .0 matching the app's "0 minutes" pins the scale. Whether
-        # it counts up or down is NOT established -- it was seen rising (171.0 ->
-        # 171.5) while the unit ran, which contradicts the app's "remaining"
-        # wording, so the entity is deliberately named neutrally.
+        # unit, and the .0 matching the app's "0 minutes" pins the scale.
+        #
+        # It counts UP -- running time accumulated since the last filter reset,
+        # not time remaining. An earlier revision of this comment called the
+        # direction unestablished; three independent things now settle it. It was
+        # seen rising while the unit ran (171.0 -> 171.5). FilterAlarmTime_ in the
+        # same options[] blob is the threshold it is measured against (500 on
+        # every unit on record). And across two units on one site, the alarm
+        # tracks the counter in the right direction: at FilterTime_5595 the
+        # /alarms/vs/0 filter entry is live (unsuffixed code 'FilterAlarm', state
+        # 'Created'), while at FilterTime_1915 it is still the
+        # 'FilterAlarm_OFF'/'Deleted' placeholder. That also matches what the app
+        # does at 500 hours -- ask the user to clean the filter and reset it.
+        #
+        # The key stays 'filter_time' rather than becoming something like
+        # filter_time_elapsed: renaming it would change every existing unit's
+        # entity_id and unique_id for a wording improvement.
+        #
+        # (The alarm clearing on its own is the causal proof of the direction
+        # above: the board recomputes it the moment the counter crosses the
+        # threshold, rather than the app clearing counter and alarm separately.)
+        #
+        # ---------------------------------------------------------------------
+        # RESETTING THIS COUNTER: NOT SOLVED YET -- no reset entity here, and
+        # the notes below are so the next attempt starts from the evidence
+        # rather than from scratch. I could not work out how to drive the reset
+        # locally; that is not the same as it being impossible, and none of the
+        # results below rule out a mechanism I simply haven't found.
+        #
+        # What the reset actually is: a *command*, not a value write. Samsung
+        # models it as capability `custom.dustFilter`, command
+        # `resetDustFilter`, no arguments (implemented in several SmartThings HA
+        # forks; not in the core integration). That reframes every failed
+        # attempt below -- nothing changes the counter by writing to it,
+        # because the board zeroes it itself on receiving a command.
+        #
+        # Tried, all against a live unit, all failed:
+        #   * FilterTime_0 via the single-token options merge that works for
+        #     every other setting on this href -- accepted with no error, then
+        #     discarded. Two units, opposite power states, to rule out the
+        #     obvious confound: 5595 -> back to 5595 after 69 s (powered off,
+        #     alarm active) and 1925 -> back to 1925 after 65 s (actively
+        #     cooling).
+        #   * A full options[] read-modify-write with FilterTime_0 substituted,
+        #     instead of the single-token merge -- zero fields changed anywhere.
+        #   * A write to /consumable/vs/0, the board's own filter resource
+        #     (items[{name: FilterProgress, state: N}]) -- discarded. /oic/res
+        #     declares that resource oic.if.s, i.e. read-only, which fits.
+        #   * /actions/vs/0 (x.com.samsung.da.actions, oic.if.a) is the obvious
+        #     local command channel, but publishes no schema: GET returns {} on
+        #     baseline and on oic.if.a, and five POSTs probing the *shape*
+        #     (empty map, empty string, empty array, invalid value, items shape)
+        #     all returned 4.00 with an empty body -- no echo of accepted field
+        #     names, unlike the laundry firmware's "Control fail, <...>". I
+        #     deliberately did not enumerate guessed action names against a live
+        #     appliance: an unknown vocabulary on a channel called "actions" can
+        #     hold a factory reset next to the one we want.
+        #   * /hass/state/vs/0 and /hass/command/vs/0 (advertised in /oic/res,
+        #     and /opt/data/hass.db exists in /file/list) -> 4.04 on every
+        #     interface, so unimplemented scaffolding on this firmware.
+        #   * /file/transfer/vs/0 serves only /mnt/usage.db; selecting another
+        #     path returns 4.05/4.00, so the firmware can't be pulled that way
+        #     to read the action vocabulary out of it.
+        #   * /rm/micomdata/vs/0 (channel toward the MICOM board the physical
+        #     panel talks to) stays empty even after successfully enabling
+        #     remote management.
+        #
+        # What the failures are NOT: a transport, permission or cert problem.
+        # A control write of rmState on /rm/state/vs/0 was accepted (2.04
+        # Changed, value held, restored afterwards), and FilterAlarmTime_ below
+        # is written through the very same options merge and kept. So writes
+        # work; this one value just isn't driven that way.
+        #
+        # Where I'd look next: the action vocabulary for /actions/vs/0 from an
+        # independent source (firmware image, or a capture of what the cloud
+        # sends the device), or the IR path -- the physical remote has a filter
+        # reset (Options -> Filter Reset -> SET), and IRremoteESP8266 decodes
+        # this AC family, though issue #1277's dump doesn't include that button.
+        # ---------------------------------------------------------------------
         SensorDesc(key='filter_time',
                    rep_fn=_option_token_num('FilterTime', divisor=10),
                    exists_fn=_has_option_token('FilterTime'),
                    device_class='duration', unit='h',
                    state_class='measurement', icon='mdi:air-filter'),
+        # The interval FilterTime_ is measured against -- the app offers it as a
+        # four-way radio (180/300/500/700 hours, default 500) next to the filter
+        # reminder. The token value is the hour count verbatim: captured by
+        # watching all 19 resources while the owner stepped through every radio
+        # position, one field changing per step and nothing else moving.
+        #
+        # Static options here, unlike air_filter_threshold on the newer boards
+        # which reads supportedFilterDesiredUsage: options[] tokens carry no
+        # supported-values list anywhere in this board's dump, so there is
+        # nothing to read them from. The four values are the app's own radio
+        # rather than a guess extrapolated from one observed value -- but a
+        # board offering different steps would need this revisited, which is
+        # why the tuple is documented rather than just written down.
+        SelectDesc(key='filter_alarm_time',
+                   rep_fn=lambda rep: _option_token(rep, 'FilterAlarmTime'),
+                   exists_fn=_has_option_token('FilterAlarmTime'),
+                   options=('180', '300', '500', '700'),
+                   write_fn=_option_switch_write('FilterAlarmTime'),
+                   icon='mdi:alarm', entity_category='config'),
         # Odor-controller ("Smart Cool Clean") state + progress -- see
         # _odor_controller_active's docstring for the cloud-capability
         # correspondence. Present on TP1X_DA-AC-RAC-01001 (issue reporter's
@@ -648,6 +742,25 @@ AUTO_CLEAN = Capability(
                    write_fn=lambda p, rep, href=None: (
                        ['option', 'autoclean', 'vs', '0'],
                        {'x.com.samsung.da.settingStatus': 'On' if p == 'On' else 'Off'})),
+        # The cycle, as opposed to the switch above -- `settingStatus` says the
+        # feature is enabled, which it is whether or not the unit is drying right
+        # now. `status` is the run state, and the resource advertises exactly
+        # Start/Stop in `supportedStatus`. Observed on a TP1X_DA-AC-CAC-01001:
+        # 'Start' with progress 98 while a cycle ran, then 'Stop' with progress 0
+        # the moment it finished.
+        BinarySensorDesc(key='auto_clean_running',
+                         field='x.com.samsung.da.status',
+                         icon='mdi:spray-bottle',
+                         entity_category='diagnostic',
+                         value_fn=lambda v: v == 'Start'),
+        # Percent through that cycle, matching the figure the appliance shows on
+        # its own display (checked against 55% mid-run).
+        SensorDesc(key='auto_clean_progress',
+                   field='x.com.samsung.da.progress',
+                   icon='mdi:progress-clock',
+                   unit='%', state_class='measurement',
+                   entity_category='diagnostic',
+                   value_fn=common.int_or_none),
     ),
 )
 

custom_components/localthings/registry/capabilities/ehs.py

@@ -0,0 +1,204 @@
+"""Capabilities for the Samsung EHS (Eco Heating System) air-to-water heat
+pump family (TP1X_DA_AC_EHS-class, model TP1X_DA_AC_EHS_01001_0000).
+
+An EHS unit runs two independently-controlled loops off one outdoor unit:
+space heating/cooling ("zone1", through /mode/vs/0, /power/vs/0,
+/temperatures/indoor/vs/0) and domestic hot water ("dhw", through
+/mode/dhw/vs/0, /power/dhw/vs/0, /temperatures/dhw/vs/0). There's no shared
+vocabulary with the room-AC family in airconditioner.py beyond the DA_AC_
+board prefix -- EHS reports its own /mode/*/vs/0 and /temperatures/*/vs/0
+shapes, not airconditioner.py's HREF_MODE/HREF_TEMP* OCF-pattern hrefs.
+
+zone1 has no HA platform with matching semantics (it's a leaving-water-
+temperature setpoint, not a thermostat with HVAC modes airconditioner.py's
+climate.py would fit), so it stays switch/select/number/sensor -- same shape
+as dehumidifier.py's power/mode/humidity split. dhw is a real HA
+water_heater.py -- see DHW below and water_heater.py's module docstring --
+following the same primary-resource-plus-sibling-reads pattern as
+airconditioner.py's CLIMATE/climate.py.
+
+Verified against a real TP1X_DA_AC_EHS_01001_0000 diagnostics dump
+(firmware AEH-WW-TP1-22-AE6000_17260402, TizenRT 3.1 / DAWIT 2.0).
+"""
+from ..capability import Capability
+from ..entities import NumberDesc, SelectDesc, SensorDesc, SwitchDesc, WaterHeaterDesc
+from .common import normalize_temp_unit
+
+
+def _num(v):
+    try:
+        return float(v)
+    except (TypeError, ValueError):
+        return None
+
+
+def _first_mode(rep):
+    """Representative scalar for a mode select -- `modes` is a single-element
+    list on every dump seen so far, mirroring airconditioner._first_mode /
+    dehumidifier._first_mode's handling of the same field shape."""
+    modes = rep.get('x.com.samsung.da.modes')
+    if isinstance(modes, (list, tuple)):
+        return modes[0] if modes else None
+    return modes
+
+
+def _temp_unit(rep):
+    return normalize_temp_unit(rep.get('x.com.samsung.da.unit'), '°C')
+
+
+def _bounds(rep, default_min, default_max):
+    """The resource's own (minimum, maximum) pair, or the defaults.
+
+    Both ends together or neither -- a board reporting only one would
+    otherwise pair a real device bound with an invented default, which
+    looks plausible and is silently wrong. Same rule as
+    climate._range()/water_heater._range(), and the same reason
+    oven._setpoint_bounds resolves its pair in one place.
+    """
+    lo = _num(rep.get('x.com.samsung.da.minimum'))
+    hi = _num(rep.get('x.com.samsung.da.maximum'))
+    return (lo, hi) if (lo is not None and hi is not None) else (default_min, default_max)
+
+
+def _step(rep, default):
+    """`is None`, not `or` -- `or` collapses a genuine 0 (issue #160)."""
+    step = _num(rep.get('x.com.samsung.da.increment'))
+    return default if step is None else step
+
+
+ZONE_POWER = Capability(
+    href='/power/vs/0',
+    poll_tier='warm',
+    entities=(
+        SwitchDesc(key='zone_power', field='x.com.samsung.da.power',
+                   icon='mdi:radiator',
+                   value_fn=lambda v: v == 'On',
+                   write_fn=lambda p, rep, href=None: (
+                       ['power', 'vs', '0'],
+                       {'x.com.samsung.da.power': 'On' if p == 'On' else 'Off'})),
+    ),
+)
+
+ZONE_MODE = Capability(
+    href='/mode/vs/0',
+    poll_tier='warm',
+    entities=(
+        SelectDesc(key='zone_mode', rep_fn=_first_mode,
+                   icon='mdi:sun-snowflake-variant',
+                   options_field='x.com.samsung.da.supportedModes',
+                   write_fn=lambda p, rep, href=None: (
+                       ['mode', 'vs', '0'], {'x.com.samsung.da.modes': [p]})),
+    ),
+)
+
+# type=Water/unit=Celsius on this dump names the space-heating loop's flow/
+# room setpoint, not a literal water temperature -- Samsung EHS zone control
+# is leaving-water-temperature-based, same convention as the dhw loop below.
+ZONE_TEMPERATURE = Capability(
+    href='/temperatures/indoor/vs/0',
+    poll_tier='warm',
+    entities=(
+        SensorDesc(key='zone_temperature', field='x.com.samsung.da.current',
+                   device_class='temperature', unit_fn=_temp_unit,
+                   state_class='measurement', value_fn=_num),
+        NumberDesc(key='zone_target_temperature', field='x.com.samsung.da.desired',
+                   device_class='temperature', unit_fn=_temp_unit,
+                   entity_category='config', value_fn=_num,
+                   native_min_fn=lambda rep: _bounds(rep, 5.0, 30.0)[0],
+                   native_max_fn=lambda rep: _bounds(rep, 5.0, 30.0)[1],
+                   step_fn=lambda rep: _step(rep, 0.5),
+                   write_fn=lambda p, rep, href=None: (
+                       ['temperatures', 'indoor', 'vs', '0'],
+                       {'x.com.samsung.da.desired': str(float(p))})),
+    ),
+)
+
+# Canonical dhw resource hrefs. water_heater.py binds the primary HREF_DHW_MODE
+# via DHW below and reads the sibling power/temperature hrefs off the
+# coordinator snapshot -- same primary-plus-siblings shape as
+# airconditioner.py's HREF_MODE/CLIMATE_CONSUMED_HREFS. Declared once here
+# and imported by water_heater.py, so a new sibling read can't drift out of
+# sync with its DHW_CONSUMED_HREFS coverage entry below.
+HREF_DHW_POWER = '/power/dhw/vs/0'              # on/off
+HREF_DHW_MODE = '/mode/dhw/vs/0'                # primary (bound by DHW) -- current_operation
+HREF_DHW_TEMPERATURE = '/temperatures/dhw/vs/0'  # current/target temperature
+
+DHW_CONSUMED_HREFS = [HREF_DHW_POWER, HREF_DHW_TEMPERATURE]
+
+
+def _dhw_write(payload, rep, href=None):
+    """Map a (kind, value) command from the water_heater platform to the
+    (path_segs, body) for that one sub-write -- same contract as
+    airconditioner._climate_write, just across the dhw loop's three
+    resources instead of the AC's power/mode/temperature/wind set."""
+    kind, value = payload
+    if kind == 'power':
+        return (['power', 'dhw', 'vs', '0'],
+                {'x.com.samsung.da.power': 'On' if value else 'Off'})
+    if kind == 'mode':
+        return (['mode', 'dhw', 'vs', '0'], {'x.com.samsung.da.modes': [value]})
+    if kind == 'temperature':
+        return (['temperatures', 'dhw', 'vs', '0'],
+                {'x.com.samsung.da.desired': str(float(value))})
+    return None
+
+
+DHW = Capability(
+    href=HREF_DHW_MODE,
+    poll_tier='warm',
+    entities=(
+        WaterHeaterDesc(key='water_heater', translation_key='dhw',
+                         rep_fn=_first_mode, write_fn=_dhw_write),
+    ),
+)
+
+# Power and temperature are read by the composite DHW entity above, not
+# given their own entities -- coverage-only caps so discover() reports no
+# gap (see airconditioner.py's CLIMATE_CONSUMED_HREFS for the same pattern).
+DHW_CONSUMED = [Capability(href=h, poll_tier='warm') for h in DHW_CONSUMED_HREFS]
+
+# Deliberately a plain config switch, not water_heater's AWAY_MODE feature.
+# HA core's smartthings water_heater does wire this same Samsung capability
+# (CUSTOM_OUTING_MODE) up to WaterHeaterEntityFeature.AWAY_MODE, and the DHW
+# operation-mode map above is taken from that integration -- so the
+# divergence is worth stating. /option/outgoing/vs/0 is device-wide: one
+# `away` flag covering the whole unit, zone1 included (it has no dhw-scoped
+# sibling href, unlike every other resource in this loop). Hanging it off
+# the DHW card would present a device-wide setting as if it only affected
+# hot water. It stays a switch until a board turns up with a per-loop away
+# resource to bind instead.
+AWAY_MODE = Capability(
+    href='/option/outgoing/vs/0',
+    poll_tier='cold',
+    entities=(
+        SwitchDesc(key='away_mode', field='x.com.samsung.da.away',
+                   icon='mdi:home-export-outline',
+                   entity_category='config',
+                   value_fn=lambda v: v == 'On',
+                   write_fn=lambda p, rep, href=None: (
+                       ['option', 'outgoing', 'vs', '0'],
+                       {'x.com.samsung.da.away': 'On' if p == 'On' else 'Off'})),
+    ),
+)
+
+# ---------------------------------------------------------------------------
+# EHS-scoped coverage: opaque vendor plumbing (hex-encoded factory/cycle/
+# schedule blobs) or resources with no confirmed write contract on this
+# dump, following the same 'don't guess' rule as dehumidifier._DHM_IGNORED.
+# Not in the global ignored.IGNORED since these are EHS-only shapes that
+# would need their own verification on other device families.
+# ---------------------------------------------------------------------------
+_EHS_IGNORED = [
+    '/availablecontrolsets/vs/0',  # opaque hex-encoded control-set bitmap (id: EHS)
+    '/da/softreset/vs/0',          # soft-reset trigger plumbing
+    '/diagnosis/vs/0',             # empty {} on this dump
+    '/ehscycle/vs/0',              # opaque hex-encoded indoor/outdoor cycle log
+    '/ehsfsv/vs/0',                # opaque hex-encoded factory setting values
+    '/option/dhwdisplay/vs/0',     # front-panel DHW-display show/hide, cosmetic only
+    '/reserverulesets/vs/0',       # opaque hex-encoded schedule reservation blob
+    '/sac/installationinfo/vs/0',  # static outdoor/indoor installation info, diagnostic only
+    '/actions/zone1/vs/0',         # zone1 schedule/timer program -- unmodeled for now
+    '/actions/dhw/vs/0',           # DHW schedule/timer program -- unmodeled for now
+]
+
+COVERAGE = [Capability(href=h) for h in _EHS_IGNORED]

custom_components/localthings/registry/entities.py

@@ -133,6 +133,16 @@ class FanDesc(SamsungEntityDescription):
     write_fn: WriteFn = None
 
 
+@dataclass(frozen=True, kw_only=True)
+class WaterHeaterDesc(SamsungEntityDescription):
+    # Composite water_heater entity: binds one primary resource (its href,
+    # typically an operation-mode resource) but the water_heater platform
+    # reads sibling resources (power, temperature) from the coordinator
+    # snapshot and writes to several of them. Same (kind, value) -> (path_segs,
+    # body) write_fn shape as ClimateDesc/FanDesc.
+    write_fn: WriteFn = None
+
+
 PLATFORM_OF: dict[type, str] = {
     SensorDesc:       'sensor',
     BinarySensorDesc: 'binary_sensor',
@@ -143,4 +153,5 @@ PLATFORM_OF: dict[type, str] = {
     TimeDesc:         'time',
     ClimateDesc:      'climate',
     FanDesc:          'fan',
+    WaterHeaterDesc:  'water_heater',
 }

custom_components/localthings/registry/subdevices.py

@@ -36,7 +36,18 @@ the only thing ever actually confirmed to work for this pattern -- on the
 assumption that a composite device's siblings share the master's resource
 surface. See `Subdevice.flat_hrefs`.
 
-Both are "the same thing wearing different clothes": a logical subdevice is a
+Pattern C -- UUID prefix advertised only via `/oic/res`
+(`AWM-WW-AID-26-ONEBODY` washer+dryer combo, issue #241). The board answers
+`numofsubdevice='2'` on `/multidevice/vs/0` but has no `/subdevices/vs/0`
+(no `subdeviceIdList`) and 4.04s `/device/1`/`/device/2`; the washer
+subdevice's UUID appears nowhere except as the path prefix of the
+`x.com.samsung.da.multidevice` link in `/oic/res`, and
+`GET /<uuid>/device/0` answers the washer's own full Collection batch
+(model `..._WF80H` vs. the master's `..._DV80H27H`) -- Pattern B's
+transform with the UUID sourced from the link prefix instead of
+`subdeviceIdList`.
+
+All of these are "the same thing wearing different clothes": a logical subdevice is a
 seed collection path to poll, plus an href transform between the canonical
 href the registry knows (`/mode/vs/0`) and the actual on-the-wire href. The
 detection signals don't overlap on either captured board (the Pattern A
@@ -88,6 +99,12 @@ from .batch import parse_device0_batch
 
 _INDEXED_HREF_RE = re.compile(r'^/device/(\d+)$')
 
+# A UUID as the first path segment of an /oic/res link href -- Pattern C's
+# discovery signal (issue #241): a subdevice tree whose UUID is advertised
+# nowhere except as this prefix (no subdeviceIdList, no /device/<n>).
+_UUID_PREFIX_RE = re.compile(
+    r'^/([0-9a-fA-F]{8}(?:-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12})/')
+
 # Speculative /device/<n> siblings probed when /oic/res doesn't reveal a
 # second logical subdevice's Collection on this board (moved here from
 # identity.py, issue #177 -- see enumerate_subdevices' docstring for why: the
@@ -333,22 +350,26 @@ def enumerate_subdevices(
     """
     subdevices: list[Subdevice] = []
     fetched: dict[str, dict] = {}
+    # Case-insensitive -- the same UUID can reach here once from
+    # subdeviceIdList and once from an /oic/res link prefix with different
+    # casing (Samsung's own fields disagree on this elsewhere too, e.g. the
+    # redaction-prone subdeviceIdList handling below), and probing it twice
+    # would materialize the same physical subdevice as two Subdevice
+    # candidates under two different keys.
+    probed_ids: set[str] = set()
 
     def _probed(seed_href: str, batch: dict) -> None:
         if probe_log is not None:
             probe_log(seed_href, bool(batch))
 
-    # --- Pattern B: UUID-prefixed tree (TP2X_FAC_BORA_21K) ------------------
-    raw_ids = (resources.get('/subdevices/vs/0') or {}).get(
-        'x.com.samsung.da.subdeviceIdList')
-    # Tolerate anything but a list of strings -- this field is redaction-prone
-    # (it matches the 'deviceid' substring rule in redact.py) and the existing
-    # airconditioner_fac_bora fixture carries the literal string
-    # '**REDACTED**'/'REDACTED' there. That must yield zero subdevices, not a
-    # crash -- issue #177 is additive, it must never break an already-working
-    # single-climate-entity device.
-    ids = raw_ids if isinstance(raw_ids, list) else []
-    for sub_id in sorted(i for i in ids if isinstance(i, str) and i):
+    def _probe_prefixed(sub_id: str) -> None:
+        """Materialize one UUID-prefixed subdevice candidate -- shared by
+        Pattern B (ids from subdeviceIdList) and Pattern C (ids from
+        /oic/res link prefixes) below, which differ only in where the UUID
+        came from."""
+        if sub_id.lower() in probed_ids:
+            return
+        probed_ids.add(sub_id.lower())
         seed = (sub_id, 'device', '0')
         batch = _get_batch(sess, seed)
         _probed(_seed_href(seed), batch)
@@ -356,7 +377,7 @@ def enumerate_subdevices(
             subdevice = Subdevice(kind='prefixed', key=sub_id, seed_path=seed)
             fetched.update(normalize_seed_batch(subdevice, batch))
             subdevices.append(subdevice)
-            continue
+            return
         # Fallback (issue #205): TP2X_FAC_BORA_21K itself -- the board this
         # pattern was built against -- turns out not to always expose its own
         # `/<uuid>/device/0` Collection either, so "every prefixed subdevice
@@ -393,12 +414,53 @@ def enumerate_subdevices(
                 flat_hrefs.append(href)
                 fetched[actual] = rep
         if not flat_hrefs:
-            continue
+            return
         subdevices.append(Subdevice(
             kind='prefixed', key=sub_id, seed_path=(),
             flat_hrefs=tuple(flat_hrefs),
         ))
 
+    # --- Pattern B: UUID-prefixed tree (TP2X_FAC_BORA_21K) ------------------
+    raw_ids = (resources.get('/subdevices/vs/0') or {}).get(
+        'x.com.samsung.da.subdeviceIdList')
+    # Tolerate anything but a list of strings -- this field is redaction-prone
+    # (it matches the 'deviceid' substring rule in redact.py) and the existing
+    # airconditioner_fac_bora fixture carries the literal string
+    # '**REDACTED**'/'REDACTED' there. That must yield zero subdevices, not a
+    # crash -- issue #177 is additive, it must never break an already-working
+    # single-climate-entity device.
+    ids = raw_ids if isinstance(raw_ids, list) else []
+    listed = sorted(i for i in ids if isinstance(i, str) and i)
+    for sub_id in listed:
+        _probe_prefixed(sub_id)
+
+    # --- Pattern C: UUID prefix advertised only via /oic/res ----------------
+    # (AWM-WW-AID-26-ONEBODY washer+dryer combo, issue #241.) A third
+    # multidevice shape: the board answers numofsubdevice='2' on
+    # /multidevice/vs/0, but carries no /subdevices/vs/0 (no subdeviceIdList
+    # -- Pattern B's signal) and 4.04s /device/1 and /device/2 (Pattern A's).
+    # The only trace of the sibling is a UUID-prefixed link in /oic/res
+    # itself: the x.com.samsung.da.multidevice link,
+    # '/<uuid>/multidevice/vs/0' on the reporting board. Its washer tree
+    # answers a full Collection at /<uuid>/device/0, exactly Pattern B's
+    # transform -- so treat every UUID path prefix seen in /oic/res as a
+    # prefixed-subdevice candidate. Probing is the same tolerated-404
+    # RETRIEVE as everything else here, and discover_partitioned's
+    # entity-level liveness gate still decides materialization, so a board
+    # that advertises a UUID link without a live sibling behind it
+    # contributes nothing. _probe_prefixed's probed_ids guard -- not a set
+    # difference against `listed` here -- is what keeps an id already named
+    # by subdeviceIdList from being probed and materialized a second time,
+    # since the two sources can disagree on that UUID's case.
+    linked = sorted({
+        m.group(1)
+        for link in _iter_oic_res_hrefs(oic_res_links)
+        for m in [_UUID_PREFIX_RE.match(link.get('href', ''))]
+        if m
+    })
+    for sub_id in linked:
+        _probe_prefixed(sub_id)
+
     # --- Pattern A: indexed siblings (ARTIK051_DONGLE_FAC_18K) --------------
     indices = sorted({
         int(m.group(1))

custom_components/localthings/translations/cs.json

@@ -1,6 +1,9 @@
 {
   "entity": {
     "binary_sensor": {
+      "auto_clean_running": {
+        "name": "Automatické čištění probíhá"
+      },
       "after_run_active": {
         "name": "Dosoušení aktivní"
       },
@@ -199,6 +202,9 @@
       },
       "tropical_night_mode": {
         "name": "Tropický noční režim"
+      },
+      "zone_target_temperature": {
+        "name": "Požadovaná teplota zóny"
       }
     },
     "select": {
@@ -328,6 +334,15 @@
       "favorite_hotwater_temperature": {
         "name": "Oblíbená teplota horké vody"
       },
+      "filter_alarm_time": {
+        "name": "Interval alarmu filtru",
+        "state": {
+          "180": "180 hodin",
+          "300": "300 hodin",
+          "500": "500 hodin",
+          "700": "700 hodin"
+        }
+      },
       "finish_sound": {
         "name": "Zvuk dokončení",
         "state": {
@@ -603,9 +618,15 @@
           "none": "Vypnuto",
           "cupboard": "Do skříně"
         }
+      },
+      "zone_mode": {
+        "name": "Režim zóny"
       }
     },
     "sensor": {
+      "auto_clean_progress": {
+        "name": "Průběh automatického čištění"
+      },
       "after_run_progress": {
         "name": "Průběh dosoušení"
       },
@@ -945,6 +966,9 @@
           "icestatus_stop": "Nečinný",
           "icestatus_run": "Vyrábí led"
         }
+      },
+      "zone_temperature": {
+        "name": "Teplota zóny"
       }
     },
     "switch": {
@@ -1106,6 +1130,12 @@
       },
       "wrinkle_prevent": {
         "name": "Ochrana proti pomačkání"
+      },
+      "zone_power": {
+        "name": "Napájení zóny"
+      },
+      "away_mode": {
+        "name": "Režim nepřítomnosti"
       }
     },
     "time": {
@@ -1127,6 +1157,11 @@
       "night_start": {
         "name": "Začátek nočního osvětlení"
       }
+    },
+    "water_heater": {
+      "dhw": {
+        "name": "Teplá voda"
+      }
     }
   },
   "config": {

custom_components/localthings/translations/en.json

@@ -1,6 +1,9 @@
 {
   "entity": {
     "binary_sensor": {
+      "auto_clean_running": {
+        "name": "Auto clean running"
+      },
       "after_run_active": {
         "name": "After run active"
       },
@@ -199,6 +202,9 @@
       },
       "tropical_night_mode": {
         "name": "Tropical night mode"
+      },
+      "zone_target_temperature": {
+        "name": "Zone target temperature"
       }
     },
     "select": {
@@ -328,6 +334,15 @@
       "favorite_hotwater_temperature": {
         "name": "Favorite hot water temperature"
       },
+      "filter_alarm_time": {
+        "name": "Filter alarm interval",
+        "state": {
+          "180": "180 hours",
+          "300": "300 hours",
+          "500": "500 hours",
+          "700": "700 hours"
+        }
+      },
       "finish_sound": {
         "name": "Finish sound",
         "state": {
@@ -603,9 +618,15 @@
           "none": "Off",
           "cupboard": "Cupboard"
         }
+      },
+      "zone_mode": {
+        "name": "Zone mode"
       }
     },
     "sensor": {
+      "auto_clean_progress": {
+        "name": "Auto clean progress"
+      },
       "after_run_progress": {
         "name": "After run progress"
       },
@@ -945,6 +966,9 @@
           "icestatus_stop": "Idle",
           "icestatus_run": "Making ice"
         }
+      },
+      "zone_temperature": {
+        "name": "Zone temperature"
       }
     },
     "switch": {
@@ -1106,6 +1130,12 @@
       },
       "wrinkle_prevent": {
         "name": "Wrinkle prevent"
+      },
+      "zone_power": {
+        "name": "Zone power"
+      },
+      "away_mode": {
+        "name": "Away mode"
       }
     },
     "time": {
@@ -1127,6 +1157,11 @@
       "night_start": {
         "name": "Night light start"
       }
+    },
+    "water_heater": {
+      "dhw": {
+        "name": "Hot water"
+      }
     }
   },
   "config": {

custom_components/localthings/translations/nl.json

@@ -1,6 +1,9 @@
 {
   "entity": {
     "binary_sensor": {
+      "auto_clean_running": {
+        "name": "Auto clean actief"
+      },
       "after_run_active": {
         "name": "Nadraaien actief"
       },
@@ -199,6 +202,9 @@
       },
       "tropical_night_mode": {
         "name": "Tropische nachtmodus"
+      },
+      "zone_target_temperature": {
+        "name": "Doeltemperatuur zone"
       }
     },
     "select": {
@@ -328,6 +334,15 @@
       "favorite_hotwater_temperature": {
         "name": "Favoriete temperatuur warm water"
       },
+      "filter_alarm_time": {
+        "name": "Filteralarminterval",
+        "state": {
+          "180": "180 uur",
+          "300": "300 uur",
+          "500": "500 uur",
+          "700": "700 uur"
+        }
+      },
       "finish_sound": {
         "name": "Eindgeluid",
         "state": {
@@ -603,9 +618,15 @@
           "none": "Uit",
           "cupboard": "Kastdroog"
         }
+      },
+      "zone_mode": {
+        "name": "Zonemodus"
       }
     },
     "sensor": {
+      "auto_clean_progress": {
+        "name": "Auto clean voortgang"
+      },
       "after_run_progress": {
         "name": "Voortgang nadraaien"
       },
@@ -945,6 +966,9 @@
           "icestatus_stop": "Inactief",
           "icestatus_run": "IJs maken"
         }
+      },
+      "zone_temperature": {
+        "name": "Zonetemperatuur"
       }
     },
     "switch": {
@@ -1106,6 +1130,12 @@
       },
       "wrinkle_prevent": {
         "name": "Kreukpreventie"
+      },
+      "zone_power": {
+        "name": "Zonevoeding"
+      },
+      "away_mode": {
+        "name": "Afwezigheidsmodus"
       }
     },
     "time": {
@@ -1127,6 +1157,11 @@
       "night_start": {
         "name": "Start nachtverlichting"
       }
+    },
+    "water_heater": {
+      "dhw": {
+        "name": "Warm water"
+      }
     }
   },
   "config": {

custom_components/localthings/water_heater.py

@@ -0,0 +1,273 @@
+"""Water heater platform for Local Things.
+
+Second composite entity in this integration (see climate.py's module
+docstring for the general pattern this follows): a single HA water_heater
+card for a Samsung EHS heat pump's domestic hot water (DHW) loop. It binds
+the primary `WaterHeaterDesc` (the `/mode/dhw/vs/0` capability, DHW.entities
+in registry/capabilities/ehs.py) so the registry still tracks it, and reads
+the sibling `/power/dhw/vs/0` and `/temperatures/dhw/vs/0` resources straight
+from the coordinator snapshot -- the same cross-resource read climate.py uses
+for the AC's power/temperature/wind siblings.
+
+Writes go through `coordinator.async_send_command(bound, (kind, value))`:
+DHW's `write_fn` (ehs._dhw_write) maps each `(kind, value)` payload to the
+right `(path_segs, body)`, and `async_send_command` POSTs to those path_segs
+and applies the optimistic value/settle guard to that same href -- not the
+bound `/mode/dhw/vs/0` href -- so one descriptor drives writes to, and gets
+fresh state back for, power, mode and temperature alike.
+
+Operation-mode vocabulary: the DHW loop's four device modes (Eco/Std/Force/
+Power) map onto HA's own standard water_heater states -- the same mapping
+Home Assistant's core `smartthings` integration uses for this exact Samsung
+capability over the cloud API (`samsungce.ehsThermostat` /
+`airConditionerMode`: eco/std/force/power -> STATE_ECO/STATE_HEAT_PUMP/
+STATE_HIGH_DEMAND/STATE_PERFORMANCE), just title-cased to match this OCF
+resource's own code spelling. Reusing HA's standard states means no *state*
+translation catalog entry is needed for them (see the entity_component
+fallback in homeassistant.components.water_heater.strings.json).
+
+Naming is a separate question from that, and the answer here differs from
+climate.py's: the AC *is* the device, so its climate card takes the bare
+device name (`_attr_name = None`). An EHS unit has two loops, and the DHW
+one is not "the device" -- its siblings are named "Zone Mode"/"Zone Target
+Temperature", so a card labelled just "EHS" would misrepresent which loop
+it drives. This entity is named through the catalog like every other
+descriptor here, via the DHW descriptor's `translation_key='dhw'`
+(entity.water_heater.dhw.name -> "Hot water").
+"""
+from __future__ import annotations
+
+import logging
+
+from homeassistant.components.water_heater import (
+    STATE_ECO,
+    STATE_HEAT_PUMP,
+    STATE_HIGH_DEMAND,
+    STATE_PERFORMANCE,
+    WaterHeaterEntity,
+    WaterHeaterEntityFeature,
+)
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.const import STATE_OFF, UnitOfTemperature
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
+
+from .registry.capabilities.ehs import (
+    HREF_DHW_MODE as MODE_HREF,
+    HREF_DHW_POWER as POWER_HREF,
+    HREF_DHW_TEMPERATURE as TEMPERATURE_HREF,
+)
+from .registry.capabilities.common import normalize_temp_unit
+from .registry.entities import WaterHeaterDesc
+
+from .const import DOMAIN
+from .coordinator import LocalThingsCoordinator
+from .entity import LocalThingsEntity, _is_included
+
+_LOGGER = logging.getLogger(__name__)
+
+_MODES_FIELD = 'x.com.samsung.da.modes'
+_SUPPORTED_FIELD = 'x.com.samsung.da.supportedModes'
+
+# Device mode <-> HA water_heater operation state -- see the module
+# docstring above for the SmartThings-cloud precedent this mirrors.
+_DEVICE_TO_STATE: dict[str, str] = {
+    'Eco': STATE_ECO,
+    'Std': STATE_HEAT_PUMP,
+    'Force': STATE_HIGH_DEMAND,
+    'Power': STATE_PERFORMANCE,
+}
+_STATE_TO_DEVICE = {v: k for k, v in _DEVICE_TO_STATE.items()}
+
+# Read-side lookup, case-folded. climate.py resolves write codes from the
+# unit's own supportedModes because two spellings there mean one HA value
+# ('Wind'/'Fan' -> FAN_ONLY); this map is bijective, so the write side can
+# use _STATE_TO_DEVICE directly. Only the read side is exposed to a board
+# spelling the same code differently ('eco'/'ECO'), and case is the one
+# variation worth absorbing rather than warning about.
+_DEVICE_TO_STATE_CI = {k.lower(): v for k, v in _DEVICE_TO_STATE.items()}
+
+
+def _to_state(code) -> str | None:
+    if code is None:
+        return None
+    return _DEVICE_TO_STATE_CI.get(str(code).lower())
+
+
+async def async_setup_entry(
+    hass: HomeAssistant,
+    entry: ConfigEntry,
+    async_add_entities: AddEntitiesCallback,
+) -> None:
+    coordinator: LocalThingsCoordinator = hass.data[DOMAIN][entry.entry_id]
+    async_add_entities(
+        LocalThingsWaterHeater(coordinator, b)
+        for b in coordinator.bound
+        if isinstance(b.desc, WaterHeaterDesc) and _is_included(b, coordinator)
+    )
+
+
+def _num(value):
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return None
+
+
+def _first(value):
+    """Samsung `modes` is a single-element list on this resource. Return the
+    first element of a list, else the value itself."""
+    if isinstance(value, (list, tuple)):
+        return value[0] if value else None
+    return value
+
+
+class LocalThingsWaterHeater(LocalThingsEntity, WaterHeaterEntity):
+    """Composite water_heater entity for a Samsung EHS DHW loop."""
+
+    def __init__(self, coordinator: LocalThingsCoordinator, bound) -> None:
+        super().__init__(coordinator, bound)
+        # No _attr_name here: unlike climate.py's AC, this is one loop of a
+        # two-loop device and takes a catalog name ("Hot water") through the
+        # descriptor's translation_key -- see the module docstring.
+        self._attr_supported_features = (
+            WaterHeaterEntityFeature.TARGET_TEMPERATURE
+            | WaterHeaterEntityFeature.OPERATION_MODE
+            | WaterHeaterEntityFeature.ON_OFF
+        )
+        # Raw device codes already logged by _warn_unmapped -- these
+        # properties are read on every coordinator refresh, so an un-deduped
+        # warning would spam the log for any unit reporting a genuinely
+        # unrecognized code.
+        self._warned_unmapped: set[str] = set()
+
+    def _rep(self, href: str) -> dict:
+        """`href` is one of this module's canonical HREF_* constants --
+        translated through this bound entity's own subdevice (issue #177),
+        same as climate.py's identical helper."""
+        return self.coordinator.resource(self._bound.subdevice.to_actual(href)) or {}
+
+    def _is_on(self) -> bool:
+        return str(self._rep(POWER_HREF).get('x.com.samsung.da.power', '')).lower() == 'on'
+
+    def _supported(self) -> list[str]:
+        return list(self._rep(MODE_HREF).get(_SUPPORTED_FIELD) or [])
+
+    def _warn_unmapped(self, code: str) -> None:
+        if code in self._warned_unmapped:
+            return
+        self._warned_unmapped.add(code)
+        _LOGGER.warning(
+            "%s: device DHW mode %r has no HA mapping and was dropped; "
+            "please file an issue with your diagnostics dump",
+            self.entity_id, code,
+        )
+
+    # -- temperature --------------------------------------------------------
+
+    @property
+    def temperature_unit(self) -> str:
+        raw = self._rep(TEMPERATURE_HREF).get('x.com.samsung.da.unit')
+        return (UnitOfTemperature.FAHRENHEIT
+                if normalize_temp_unit(raw, '°C') == '°F'
+                else UnitOfTemperature.CELSIUS)
+
+    @property
+    def current_temperature(self):
+        return _num(self._rep(TEMPERATURE_HREF).get('x.com.samsung.da.current'))
+
+    @property
+    def target_temperature(self):
+        return _num(self._rep(TEMPERATURE_HREF).get('x.com.samsung.da.desired'))
+
+    def _range(self) -> list | None:
+        """The device's own (minimum, maximum) pair, or None.
+
+        Both ends together or neither, deliberately -- same rule as
+        climate._range(). A board reporting minimum but not maximum would
+        otherwise pair a device minimum (40) with HA's own default maximum
+        (140 °F), which looks plausible and is silently wrong on a unit
+        that really allows 62.
+        """
+        rep = self._rep(TEMPERATURE_HREF)
+        lo = _num(rep.get('x.com.samsung.da.minimum'))
+        hi = _num(rep.get('x.com.samsung.da.maximum'))
+        return [lo, hi] if (lo is not None and hi is not None) else None
+
+    @property
+    def min_temp(self) -> float:
+        r = self._range()
+        return r[0] if r else super().min_temp
+
+    @property
+    def max_temp(self) -> float:
+        r = self._range()
+        return r[1] if r else super().max_temp
+
+    @property
+    def target_temperature_step(self) -> float:
+        # `is None`, not `or` -- see issue #160: `or` collapses a genuine 0
+        # into the fallback.
+        step = _num(self._rep(TEMPERATURE_HREF).get('x.com.samsung.da.increment'))
+        return 0.5 if step is None else step
+
+    # -- operation mode -------------------------------------------------------
+
+    @property
+    def current_operation(self) -> str | None:
+        if not self._is_on():
+            return STATE_OFF
+        code = _first(self._rep(MODE_HREF).get(_MODES_FIELD))
+        mapped = _to_state(code)
+        if code is not None and mapped is None:
+            self._warn_unmapped(code)
+        return mapped
+
+    @property
+    def operation_list(self) -> list[str]:
+        modes = [STATE_OFF]
+        for code in self._supported():
+            mapped = _to_state(code)
+            if mapped is None:
+                self._warn_unmapped(code)
+                continue
+            if mapped not in modes:
+                modes.append(mapped)
+        return modes
+
+    # -- writes ---------------------------------------------------------------
+
+    async def async_set_temperature(self, **kwargs) -> None:
+        # HA's water_heater.set_temperature service takes an optional
+        # operation_mode and forwards it here (SET_TEMPERATURE_SCHEMA), same
+        # as climate.set_temperature does with hvac_mode. Honour it, and set
+        # it first -- that also powers the loop on when it was off -- so a
+        # dashboard "boost to 55" button that carries a mode actually changes
+        # mode, instead of only moving the setpoint. Same fix as the AC's
+        # (see climate.async_set_temperature).
+        operation_mode = kwargs.get('operation_mode')
+        if operation_mode is not None:
+            await self.async_set_operation_mode(operation_mode)
+            if operation_mode == STATE_OFF:
+                return
+        temp = kwargs.get('temperature')
+        if temp is None:
+            return
+        await self.coordinator.async_send_command(self._bound, ('temperature', temp))
+
+    async def async_set_operation_mode(self, operation_mode: str) -> None:
+        if operation_mode == STATE_OFF:
+            await self.coordinator.async_send_command(self._bound, ('power', False))
+            return
+        device = _STATE_TO_DEVICE.get(operation_mode)
+        if device is None:
+            return
+        if not self._is_on():
+            await self.coordinator.async_send_command(self._bound, ('power', True))
+        await self.coordinator.async_send_command(self._bound, ('mode', device))
+
+    async def async_turn_on(self, **kwargs) -> None:
+        await self.coordinator.async_send_command(self._bound, ('power', True))
+
+    async def async_turn_off(self, **kwargs) -> None:
+        await self.coordinator.async_send_command(self._bound, ('power', False))

tests/fixtures/ehs_device.json

@@ -0,0 +1,759 @@
+{
+  "device0": [
+    {
+      "rt": [
+        "x.com.samsung.devcol",
+        "oic.wk.col"
+      ],
+      "if": [
+        "oic.if.baseline",
+        "oic.if.ll",
+        "oic.if.b"
+      ]
+    },
+    {
+      "href": "/realtimenotiforclient/vs/0",
+      "rep": {
+        "x.com.samsung.da.timeforshortnoti": "0",
+        "x.com.samsung.da.longnotisubscription": "false",
+        "x.com.samsung.da.periodicnotisubscription": "true"
+      }
+    },
+    {
+      "href": "/alarms/vs/0",
+      "rep": {
+        "x.com.samsung.da.items": [
+          {
+            "x.com.samsung.da.id": "0",
+            "x.com.samsung.da.description": "Alarm",
+            "x.com.samsung.da.alarmType": "Device",
+            "x.com.samsung.da.code": "ErrorCode_OFF",
+            "x.com.samsung.da.triggeredTime": "2026-08-01T21:32:45",
+            "x.com.samsung.da.state": "Deleted"
+          }
+        ]
+      }
+    },
+    {
+      "href": "/temperatures/indoor/vs/0",
+      "rep": {
+        "x.com.samsung.da.type": "Water",
+        "x.com.samsung.da.desired": "5.0",
+        "x.com.samsung.da.current": "30.0",
+        "x.com.samsung.da.maximum": "25.0",
+        "x.com.samsung.da.minimum": "5.0",
+        "x.com.samsung.da.increment": "0.5",
+        "x.com.samsung.da.offset": "0.0",
+        "x.com.samsung.da.unit": "Celsius"
+      }
+    },
+    {
+      "href": "/temperatures/dhw/vs/0",
+      "rep": {
+        "x.com.samsung.da.type": "Water",
+        "x.com.samsung.da.unit": "Celsius",
+        "x.com.samsung.da.desired": "40.0",
+        "x.com.samsung.da.current": "38.0",
+        "x.com.samsung.da.maximum": "62.0",
+        "x.com.samsung.da.minimum": "40.0",
+        "x.com.samsung.da.increment": "0.5"
+      }
+    },
+    {
+      "href": "/diagnosis/vs/0",
+      "rep": {}
+    },
+    {
+      "href": "/energy/consumption/vs/0",
+      "rep": {
+        "x.com.samsung.da.cumulativePower": "2448844",
+        "x.com.samsung.da.cumulativeSavedPower": "0",
+        "x.com.samsung.da.cumulativeUnit": "Wh",
+        "x.com.samsung.da.cumulativePowerType": "individual"
+      }
+    },
+    {
+      "href": "/mode/vs/0",
+      "rep": {
+        "x.com.samsung.da.supportedModes": [
+          "Cool",
+          "Heat",
+          "Auto"
+        ],
+        "x.com.samsung.da.modes": [
+          "Cool"
+        ],
+        "x.com.samsung.da.options": [
+          "OutdoorTemp_80",
+          "KeyInputPermit_On",
+          "ModePermit_NoLimit",
+          "Thermostat_CoolHeat_Off"
+        ],
+        "x.com.samsung.da.supportedOptions": [
+          "Thermostat_CoolHeat",
+          "DurationOn",
+          "KeyInputPermit",
+          "ModePermit",
+          "Volume",
+          "OutdoorTemp"
+        ]
+      }
+    },
+    {
+      "href": "/mode/dhw/vs/0",
+      "rep": {
+        "x.com.samsung.da.supportedModes": [
+          "Eco",
+          "Std",
+          "Power",
+          "Force"
+        ],
+        "x.com.samsung.da.modes": [
+          "Eco"
+        ],
+        "x.com.samsung.da.options": [
+          "Thermostat_Dhw_Off",
+          "KeyInputPermit_On"
+        ],
+        "x.com.samsung.da.supportedOptions": [
+          "Thermostat_Dhw",
+          "KeyInputPermit"
+        ]
+      }
+    },
+    {
+      "href": "/power/vs/0",
+      "rep": {
+        "x.com.samsung.da.power": "Off",
+        "causeSource": "SMTS"
+      }
+    },
+    {
+      "href": "/power/dhw/vs/0",
+      "rep": {
+        "x.com.samsung.da.power": "On",
+        "causeSource": "SMTS"
+      }
+    },
+    {
+      "href": "/information/vs/0",
+      "rep": {
+        "x.com.samsung.da.modelNum": "TP1X_DA_AC_EHS_01001_0000|10250141|60070105001711034A00010000002000",
+        "x.com.samsung.da.description": "TP1X_DA_AC_EHS_01001_0000",
+        "x.com.samsung.da.serialNum": "**REDACTED**",
+        "x.com.samsung.da.otnDUID": "**REDACTED**",
+        "x.com.samsung.da.diagProtocolType": "BLE_OCF",
+        "x.com.samsung.da.diagLogType": [
+          "errCode",
+          "dump"
+        ],
+        "x.com.samsung.da.diagDumpType": "file",
+        "x.com.samsung.da.diagEndPoint": "SSM",
+        "x.com.samsung.da.diagMnid": "0AJT",
+        "x.com.samsung.da.diagSetupid": "AE0",
+        "x.com.samsung.da.diagMinVersion": "3.0",
+        "x.com.samsung.da.diagTsId": "DA01",
+        "x.com.samsung.da.serialNumOption": "**REDACTED**",
+        "x.com.samsung.da.items": [
+          {
+            "x.com.samsung.da.id": "0",
+            "x.com.samsung.da.description": "Version",
+            "x.com.samsung.da.type": "Software",
+            "x.com.samsung.da.number": "02504A260402",
+            "x.com.samsung.da.newVersionAvailable": "0"
+          },
+          {
+            "x.com.samsung.da.id": "1",
+            "x.com.samsung.da.description": "Version",
+            "x.com.samsung.da.type": "Firmware",
+            "x.com.samsung.da.number": "02501A24062401,FFFFFFFFFFFFFF",
+            "x.com.samsung.da.newVersionAvailable": "0"
+          },
+          {
+            "x.com.samsung.da.id": "2",
+            "x.com.samsung.da.description": "Version",
+            "x.com.samsung.da.type": "Outdoor",
+            "x.com.samsung.da.number": "02572A23081000,02549A10000800"
+          }
+        ]
+      }
+    },
+    {
+      "href": "/file/information/vs/0",
+      "rep": {
+        "x.com.samsung.timeoffset": "+01:00",
+        "x.com.samsung.supprtedtype": 1
+      }
+    },
+    {
+      "href": "/configuration/vs/0",
+      "rep": {
+        "x.com.samsung.da.region": "0000000000"
+      }
+    },
+    {
+      "href": "/drlc/vs/0",
+      "rep": {
+        "x.com.samsung.da.drlcLevel": "0",
+        "x.com.samsung.da.durationminutes": "0",
+        "x.com.samsung.da.drlcStartTime": "1970-01-01T00:00:00Z",
+        "x.com.samsung.da.override": "Off",
+        "x.com.samsung.da.realSaving": "Off"
+      }
+    },
+    {
+      "href": "/availablecontrolsets/vs/0",
+      "rep": {
+        "x.com.samsung.da.sets": "0001003200FA0B0190026C0C0000CE32",
+        "x.com.samsung.da.id": "EHS",
+        "x.com.samsung.da.version": "1.0"
+      }
+    },
+    {
+      "href": "/da/softreset/vs/0",
+      "rep": {
+        "x.com.samsung.da.softwarereset": "false"
+      }
+    },
+    {
+      "href": "/otninformation/vs/0",
+      "rep": {
+        "x.com.samsung.da.target": "",
+        "x.com.samsung.da.newVersionAvailable": "false",
+        "x.com.samsung.da.newVersionNo": "00000000",
+        "x.com.samsung.da.currentVersionInfo": "00000000",
+        "otnStatus": "None",
+        "flashingProgress": "",
+        "otnTarget": "main",
+        "otnCompleteDate": "noHistory",
+        "otnList": [
+          {
+            "type": "WIFI",
+            "modelId": "AEH-WW-TP1-22-AE6000",
+            "versions": [
+              "17260402"
+            ],
+            "visVersion": "260402"
+          },
+          {
+            "type": "Micom",
+            "modelId": "040010250141FFFFFFFF",
+            "versions": [
+              "24062401",
+              "FFFFFFFF"
+            ],
+            "visVersion": "240624"
+          },
+          {
+            "type": "Micom",
+            "modelId": "04001025724110254941",
+            "versions": [
+              "23081000",
+              "10000800"
+            ],
+            "visVersion": "230810"
+          }
+        ]
+      }
+    },
+    {
+      "href": "/timezone/vs/0",
+      "rep": {
+        "timezoneid": "Europe/London",
+        "offset": "+01:00",
+        "DST": "ON"
+      }
+    },
+    {
+      "href": "/option/muteonce/vs/0",
+      "rep": {
+        "muteonce": "Off"
+      }
+    },
+    {
+      "href": "/reserverulesets/vs/0",
+      "rep": {
+        "x.com.samsung.da.sets": "0EFFFFFFFF05190F370B283E",
+        "x.com.samsung.da.id": "EHS",
+        "x.com.samsung.da.version": "1.0"
+      }
+    },
+    {
+      "href": "/connectionconfig/vs/0",
+      "rep": {
+        "autoReconnectionMinVersion": "1.0",
+        "autoReconnection": "true",
+        "autoReconnectionProtocolType": [
+          "helper_hotspot",
+          "ble_ocf"
+        ],
+        "supportedWiFiAuthType": [
+          "OPEN",
+          "WEP",
+          "WPA-PSK",
+          "WPA2-PSK",
+          "SAE"
+        ],
+        "supportedWiFiCryptoType": [
+          "TKIP",
+          "AES",
+          "WEP-64",
+          "WEP-128"
+        ],
+        "supportedWiFiFreq": [
+          "2.4G"
+        ],
+        "calmConnectionCare": {
+          "version": "1.0",
+          "role": [
+            "things"
+          ]
+        }
+      }
+    },
+    {
+      "href": "/option/outgoing/vs/0",
+      "rep": {
+        "x.com.samsung.da.away": "Off"
+      }
+    },
+    {
+      "href": "/sac/installationinfo/vs/0",
+      "rep": {
+        "installationOptions": [
+          {
+            "id": "0",
+            "option": "12300000000000000000"
+          },
+          {
+            "id": "1",
+            "option": "20010000000000000000"
+          },
+          {
+            "id": "2",
+            "option": "50000000000000000000"
+          },
+          {
+            "id": "3",
+            "option": "30000000000000000000"
+          }
+        ],
+        "installationDeviceNum": [
+          {
+            "id": "0",
+            "number": "01"
+          },
+          {
+            "id": "1",
+            "number": "01"
+          },
+          {
+            "id": "2",
+            "number": "00"
+          }
+        ],
+        "outdoorInfo": [
+          {
+            "id": "0",
+            "info": "02572A230810",
+            "serial": "**REDACTED**"
+          },
+          {
+            "id": "1",
+            "info": "000000000000",
+            "serial": "**REDACTED**"
+          },
+          {
+            "id": "2",
+            "info": "000000000000",
+            "serial": "**REDACTED**"
+          },
+          {
+            "id": "3",
+            "info": "000000000000",
+            "serial": "**REDACTED**"
+          }
+        ],
+        "mcuInfo": [
+          {
+            "id": "0",
+            "info": "000000000000"
+          },
+          {
+            "id": "1",
+            "info": "000000000000"
+          },
+          {
+            "id": "2",
+            "info": "000000000000"
+          },
+          {
+            "id": "3",
+            "info": "000000000000"
+          },
+          {
+            "id": "4",
+            "info": "000000000000"
+          },
+          {
+            "id": "5",
+            "info": "000000000000"
+          },
+          {
+            "id": "6",
+            "info": "000000000000"
+          },
+          {
+            "id": "7",
+            "info": "000000000000"
+          },
+          {
+            "id": "8",
+            "info": "000000000000"
+          },
+          {
+            "id": "9",
+            "info": "000000000000"
+          },
+          {
+            "id": "10",
+            "info": "000000000000"
+          },
+          {
+            "id": "11",
+            "info": "000000000000"
+          },
+          {
+            "id": "12",
+            "info": "000000000000"
+          },
+          {
+            "id": "13",
+            "info": "000000000000"
+          },
+          {
+            "id": "14",
+            "info": "000000000000"
+          },
+          {
+            "id": "15",
+            "info": "000000000000"
+          }
+        ]
+      }
+    },
+    {
+      "href": "/ehsfsv/vs/0",
+      "rep": {
+        "items": [
+          {
+            "setting": "0407010A01017202EE02260101"
+          },
+          {
+            "setting": "0408010A010096017200960101"
+          },
+          {
+            "setting": "041B010A0101F402BC026C0101"
+          },
+          {
+            "setting": "041C010A01012C019001900101"
+          },
+          {
+            "setting": "07DB010A01FF380032FFE20101"
+          },
+          {
+            "setting": "07DC010A01006400C800960101"
+          },
+          {
+            "setting": "07E5010A0100AA02EE01540101"
+          },
+          {
+            "setting": "07E6010A0100AA02EE014A0101"
+          },
+          {
+            "setting": "07EF010A0100AA02EE028A0101"
+          },
+          {
+            "setting": "07F0010A0100AA02EE00AA0101"
+          },
+          {
+            "setting": "082B0101000000000400000101"
+          },
+          {
+            "setting": "082C0101000000000400000101"
+          },
+          {
+            "setting": "082D0101000001000400040101"
+          },
+          {
+            "setting": "0BC30101000000000200020101"
+          },
+          {
+            "setting": "0BFF0101000000000100000101"
+          },
+          {
+            "setting": "0FAB0101000000000100000101"
+          },
+          {
+            "setting": "0FAC010A01FF6A00C800000101"
+          },
+          {
+            "setting": "0FB50101000000000200000101"
+          },
+          {
+            "setting": "0FCA010A010032009600640101"
+          },
+          {
+            "setting": "0FDD0101000000000100000101"
+          }
+        ]
+      }
+    },
+    {
+      "href": "/ehscycle/vs/0",
+      "rep": {
+        "indoor": [
+          {
+            "cycledata": "4B055455050500000000000000000000000000000004CCA70000005D05054B",
+            "datetime": "2026-08-01T21:23:08"
+          },
+          {
+            "cycledata": "4B055454050500000000000000000000000000000004CCAC0000005D05054B",
+            "datetime": "2026-08-01T21:28:08"
+          }
+        ],
+        "outdoor": [
+          {
+            "cycledata": "00000000555A4A53490207D000000000FFFF00480046325700000000",
+            "datetime": "2026-08-01T21:23:08"
+          },
+          {
+            "cycledata": "00000000555A4952490207D000000000000000480046325600000000",
+            "datetime": "2026-08-01T21:28:08"
+          }
+        ],
+        "unit": "Celsius"
+      }
+    },
+    {
+      "href": "/option/dhwdisplay/vs/0",
+      "rep": {
+        "x.com.samsung.da.dhwdisplay": "Show"
+      }
+    },
+    {
+      "href": "/actions/zone1/vs/0",
+      "rep": {}
+    },
+    {
+      "href": "/actions/dhw/vs/0",
+      "rep": {
+        "x.com.samsung.da.items": [
+          {
+            "x.com.samsung.da.timelineId": "0",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Sun"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "1",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Mon"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "2",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Tue"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "3",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Wed"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "4",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Thu"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "5",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Fri"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "x.com.samsung.da.timelineId": "6",
+            "x.com.samsung.da.module": "DHW",
+            "x.com.samsung.da.temperatureType": "Water",
+            "x.com.samsung.da.dayofWeek": [
+              "Sat"
+            ],
+            "x.com.samsung.da.timeblocks": [
+              {
+                "x.com.samsung.da.timeblockId": "0",
+                "x.com.samsung.da.start": [
+                  {
+                    "x.com.samsung.da.time": "03:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Std",
+                    "x.com.samsung.da.desired": "45.0"
+                  }
+                ],
+                "x.com.samsung.da.end": [
+                  {
+                    "x.com.samsung.da.time": "05:00",
+                    "x.com.samsung.da.power": "On",
+                    "x.com.samsung.da.mode": "Eco",
+                    "x.com.samsung.da.desired": "40.0"
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      }
+    }
+  ]
+}

tests/fixtures/golden/airconditioner.json

@@ -6,6 +6,8 @@
     "air_purify",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "clean_level",
     "climate",

tests/fixtures/golden/airconditioner_ara_ww_tp1_22.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_artik051_krac_18k.json

@@ -9,6 +9,7 @@
     "diagnosis_status",
     "display_light",
     "energy_kwh",
+    "filter_alarm_time",
     "filter_time",
     "good_sleep",
     "humidity",

tests/fixtures/golden/airconditioner_artik051_krac_18k_slot.json

@@ -9,6 +9,7 @@
     "diagnosis_status",
     "display_light",
     "energy_kwh",
+    "filter_alarm_time",
     "filter_time",
     "good_sleep",
     "humidity",

tests/fixtures/golden/airconditioner_artik051_krac_energy.json

@@ -9,6 +9,7 @@
     "diagnosis_status",
     "display_light",
     "energy_kwh",
+    "filter_alarm_time",
     "filter_time",
     "good_sleep",
     "humidity",

tests/fixtures/golden/airconditioner_cac.json

@@ -8,6 +8,8 @@
     "air_purify",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "clean_level",
     "climate",
     "current_temperature_c",
@@ -29,4 +31,4 @@
     "super_fine_dust",
     "tropical_night_mode"
   ]
-}
+}

tests/fixtures/golden/airconditioner_caww_tp2.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_fac_bora.json

@@ -6,6 +6,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_fac_bora_205_flat.json

@@ -6,6 +6,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_fac_bora_2in1.json

@@ -6,6 +6,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_lnx_rac_heatpump.json

@@ -7,6 +7,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_tp1x_da_ac_rac_01011.json

@@ -7,6 +7,8 @@
     "air_purify",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "clean_level",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_tp1x_rac.json

@@ -7,6 +7,8 @@
     "air_purify",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_limit_enabled",

tests/fixtures/golden/airconditioner_tp1x_rac_01001.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_tp1x_rac_coolonly.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_tp1x_rac_odor_controller.json

@@ -1,26 +1,28 @@
-{
-  "state_keys": [
-    "air_filter_status",
-    "air_filter_threshold",
-    "air_filter_usage",
-    "air_filter_usage_hours",
-    "air_purify",
-    "alarm_code",
-    "auto_clean",
-    "beep",
-    "climate",
-    "current_limit_enabled",
-    "current_limit_level",
-    "current_temperature_c",
-    "display_light",
-    "firmware_update",
-    "humidity",
-    "mute_once",
-    "odor_controller_active",
-    "odor_controller_progress",
-    "selfcheck_error",
-    "selfcheck_result",
-    "selfcheck_status",
-    "tropical_night_mode"
-  ]
-}
+{
+  "state_keys": [
+    "air_filter_status",
+    "air_filter_threshold",
+    "air_filter_usage",
+    "air_filter_usage_hours",
+    "air_purify",
+    "alarm_code",
+    "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
+    "beep",
+    "climate",
+    "current_limit_enabled",
+    "current_limit_level",
+    "current_temperature_c",
+    "display_light",
+    "firmware_update",
+    "humidity",
+    "mute_once",
+    "odor_controller_active",
+    "odor_controller_progress",
+    "selfcheck_error",
+    "selfcheck_result",
+    "selfcheck_status",
+    "tropical_night_mode"
+  ]
+}

tests/fixtures/golden/airconditioner_tp2x_rac_20k.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_windfree.json

@@ -6,6 +6,8 @@
     "air_purify",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "clean_level",
     "climate",

tests/fixtures/golden/airconditioner_windfree_oscillation.json

@@ -6,6 +6,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/airconditioner_window_ac.json

@@ -5,6 +5,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "beep",
     "climate",
     "current_temperature_c",

tests/fixtures/golden/dehumidifier.json

@@ -6,6 +6,8 @@
     "air_filter_usage_hours",
     "alarm_code",
     "auto_clean",
+    "auto_clean_progress",
+    "auto_clean_running",
     "energy_kwh",
     "energy_saved_kwh",
     "firmware_update",

tests/fixtures/golden/ehs.json

@@ -0,0 +1,15 @@
+{
+  "state_keys": [
+    "alarm_code",
+    "away_mode",
+    "energy_kwh",
+    "energy_saved_kwh",
+    "firmware_update",
+    "mute_once",
+    "water_heater",
+    "zone_mode",
+    "zone_power",
+    "zone_target_temperature",
+    "zone_temperature"
+  ]
+}

tests/fixtures/golden/qooker_mw7500a.json

@@ -0,0 +1,23 @@
+{
+  "state_keys": [
+    "alarm_code",
+    "cavity_state",
+    "child_lock",
+    "cloud_connected",
+    "cook_time",
+    "cooking_mode",
+    "current_temp_c",
+    "cycle_active",
+    "door_open",
+    "energy_kwh",
+    "finish_time",
+    "firmware_update",
+    "machine_state",
+    "operation_time_minutes",
+    "power_level",
+    "power_switch",
+    "progress_percentage",
+    "setpoint",
+    "sound"
+  ]
+}

tests/localthings/test_observe.py

@@ -452,3 +452,71 @@ def test_downgrade_to_poll_stops_refresh_task():
 
     assert not thread.is_alive()
     assert mgr._refresh_thread is None
+
+
+def test_try_enter_observe_mode_exits_early_when_fraction_reached():
+    """The grace wait returns as soon as enough hrefs notify, not after the
+    whole grace ceiling. Production data (fridge TP2X_REF_20K, 2026-07-30):
+    all subscribed hrefs notify within ~0.34s of subscribe, yet the old fixed
+    time.sleep(15) waited the remaining ~14.6s anyway — every successful
+    first-refresh / observe-retry fetch paid that dead time."""
+    mgr = _manager()
+    session = _FakeSession()
+    hrefs = ['/a/vs/0', '/b/vs/0']
+
+    def _notify_after_subscribe():
+        # Let try_enter clear _notified + subscribe first (matches the existing
+        # test pattern's 0.005 lead), then notify well before the 2s ceiling.
+        time.sleep(0.01)
+        for href in hrefs:
+            mgr.on_notification(href, cbor2.dumps({'x': 1}))
+
+    notifier = threading.Thread(target=_notify_after_subscribe, daemon=True)
+    notifier.start()
+
+    try:
+        t0 = time.monotonic()
+        entered = mgr.try_enter_observe_mode(session, hrefs, grace_period_s=2.0)
+        elapsed = time.monotonic() - t0
+        notifier.join()
+
+        assert entered is True
+        assert mgr.mode == 'observe'
+        # Early exit: returns near the notify (~0.01s), not the 2.0s ceiling.
+        # The old fixed sleep would make this >= 2.0.
+        assert elapsed < 0.5
+    finally:
+        mgr.close()
+
+
+def test_try_enter_observe_mode_waits_full_ceiling_when_fraction_not_reached():
+    """Early-exit must NOT fire below the success fraction. A partial set of
+    notifies that doesn't meet the threshold waits the full grace ceiling,
+    then falls back to poll — identical to the old fixed sleep. Guards
+    against an over-eager predicate that enters observe on too few notifies."""
+    mgr = _manager()
+    session = _FakeSession()
+    hrefs = ['/a/vs/0', '/b/vs/0', '/c/vs/0', '/d/vs/0']  # 4 hrefs
+
+    def _notify_one():
+        time.sleep(0.01)
+        mgr.on_notification(hrefs[0], cbor2.dumps({'x': 1}))  # 1/4 = 0.25
+
+    notifier = threading.Thread(target=_notify_one, daemon=True)
+    notifier.start()
+
+    try:
+        t0 = time.monotonic()
+        entered = mgr.try_enter_observe_mode(
+            session, hrefs, grace_period_s=0.2, success_fraction=0.8,
+        )
+        elapsed = time.monotonic() - t0
+        notifier.join()
+
+        assert entered is False
+        assert mgr.mode == 'poll'
+        assert mgr.subscribed_hrefs == set()
+        # Waited the full 0.2s ceiling (1/4 = 0.25 < 0.8); did not early-exit.
+        assert elapsed >= 0.18
+    finally:
+        mgr.close()

tests/test_airconditioner_artik051_krac.py

@@ -9,8 +9,8 @@ differs from all of them in three ways, each covered below:
 * No ``/mode/convenient/vs/0`` -- the convenient-mode preset is a ``Comode_*``
   token in ``/mode/vs/0``'s ``options`` array.
 * Several settings (SPI, auto clean, air monitoring, beep volume, Good Sleep,
-  outdoor temperature, filter time) are ``options`` tokens too, where newer
-  boards have dedicated resources.
+  outdoor temperature, filter time and its alarm interval) are ``options``
+  tokens too, where newer boards have dedicated resources.
 
 Fan, swing, preset, SPI and beep-volume writes were all confirmed on hardware
 by read-back on the unit this fixture is dumped from. The issue #136 unit is
@@ -103,8 +103,8 @@ def test_token_entities_present_with_calibrated_values():
     state = _state()
     # token/10 hours: 1715 displayed as "171 hours 0 minutes"... at 1710 in the
     # official app on this unit, which pins the scale (the .5 here is a later
-    # reading). Whether it counts up or down is deliberately not asserted --
-    # see the descriptor comment.
+    # reading). It counts up -- see the descriptor comment and
+    # test_filter_alarm_tracks_the_counter_against_its_threshold below.
     assert state['filter_time'] == 171.5
     # token - 55 == 19 C, against a 19.4 C forecast at the time of the dump.
     assert state['outdoor_temperature'] == 19.0
@@ -180,6 +180,82 @@ def test_option_writes_carry_one_token():
     )
 
 
+# -- filter counter and its reset ---------------------------------------------
+
+def _desc(resources, key):
+    """The bound descriptor for `key`, or None when its exists_fn declines it.
+
+    flatten() gives values, not descriptors, so this is how a test reaches a
+    descriptor's own write_fn and options without standing up an HA entity.
+    """
+    bound, _ = _discover(resources)
+    for item in bound:
+        if item.desc.key == key and (
+            item.desc.exists_fn is None
+            or item.desc.exists_fn(resources.get(item.href) or {}, resources)
+        ):
+            return item.desc
+    return None
+
+
+def test_filter_alarm_time_reads_the_threshold_and_writes_one_token():
+    """The interval FilterTime_ is measured against, offered by the app as a
+    180/300/500/700 hour radio. All four were walked on hardware while watching
+    all 19 resources: the token carries the hour count verbatim and each step
+    moved that one field and nothing else, which is also what makes a static
+    options tuple defensible here (the board advertises no supported-values
+    list for options[] tokens)."""
+    state = _state()
+    assert state['filter_alarm_time'] == '500'          # the fixture's own value
+
+    desc = _desc(_load_device(FIXTURE), 'filter_alarm_time')
+    assert desc.options == ('180', '300', '500', '700')
+    assert desc.write_fn('180', {}) == (
+        ['mode', 'vs', '0'],
+        {'x.com.samsung.da.options': ['FilterAlarmTime_180']},
+    )
+
+
+def test_filter_alarm_time_stays_off_boards_with_a_real_threshold_resource():
+    """Newer boards carry air_filter_threshold off supportedFilterDesiredUsage;
+    two thresholds on one device would be a coin flip for the user.
+
+    No non-legacy fixture carries a FilterAlarmTime_ token today (only the two
+    KRAC dumps have one at all), so asserting on an unmodified newer board
+    would pass for the wrong reason -- absent token rather than the
+    board-generation gate. The token is injected to exercise the gate itself,
+    test_absent_token_yields_no_entity's technique in reverse."""
+    newer = _load_device('airconditioner_tp1x_rac')
+    assert _desc(newer, 'filter_alarm_time') is None
+
+    mode = newer['/mode/vs/0']
+    mode['x.com.samsung.da.options'] = [
+        *(mode.get('x.com.samsung.da.options') or []), 'FilterAlarmTime_500',
+    ]
+    assert is_legacy_board(newer) is False
+    assert _desc(newer, 'filter_alarm_time') is None
+
+
+def test_filter_alarm_tracks_the_counter_against_its_threshold():
+    """Why filter_time is read as elapsed rather than remaining: the same
+    options blob carries the threshold, and /alarms/vs/0's filter entry is a
+    'FilterAlarm_OFF'/'Deleted' placeholder below it. The sibling unit on the
+    same site, at FilterTime_5595 against the same FilterAlarmTime_500, instead
+    reported an unsuffixed 'FilterAlarm' in state 'Created'."""
+    resources = _load_device(FIXTURE)
+    options = resources['/mode/vs/0']['x.com.samsung.da.options']
+    assert 'FilterTime_1715' in options
+    assert 'FilterAlarmTime_500' in options
+
+    alarms = resources['/alarms/vs/0']['x.com.samsung.da.items']
+    filter_alarm = next(
+        item for item in alarms
+        if item['x.com.samsung.da.code'].startswith('FilterAlarm')
+    )
+    assert filter_alarm['x.com.samsung.da.code'] == 'FilterAlarm_OFF'
+    assert filter_alarm['x.com.samsung.da.state'] == 'Deleted'
+
+
 # -- climate entity: fan, swing and preset off /airflow/vs/0 ------------------
 
 def test_fan_mode_reads_the_airflow_speed_level():

tests/test_by_type.py

@@ -149,6 +149,7 @@ class TestForDeviceByOicType:
         ('oic.d.oven', 'oven'),
         ('oic.d.refrigerator', 'refrigerator'),
         ('oic.d.washer', 'washer'),
+        ('x.com.st.d.hood', 'range_hood'),
         ('x.com.st.d.stickcleaner', 'vacuum_station'),
         ('x.com.st.d.steamcloset', 'air_dresser'),
         ('x.com.st.d.airqualitysensor', 'air_monitor'),
@@ -177,6 +178,18 @@ class TestForDeviceByOicType:
         from custom_components.localthings.registry.by_type import for_device_by_oic_type
         assert for_device_by_oic_type(('oic.d.robotcleaner',)) is None
 
+    def test_cooktop_is_not_mapped_to_either_cooktop_registry(self):
+        """'oic.d.cooktop' cannot tell the two cooktop families apart.
+
+        A TP1X_DA-KS-COOKTOP induction reports it, but `cooktop` is the
+        unrelated NA9300K gas family (burner state in /mode/vs/0's options
+        array, a different OCF surface -- see by_type/cooktop.py). Mapping the
+        type to either key would misroute the other, and as the primary signal
+        it would override a board token that had it right.
+        """
+        from custom_components.localthings.registry.by_type import for_device_by_oic_type
+        assert for_device_by_oic_type(('oic.d.cooktop',)) is None
+
     def test_empty_returns_none(self):
         from custom_components.localthings.registry.by_type import for_device_by_oic_type
         assert for_device_by_oic_type(()) is None
@@ -324,6 +337,20 @@ class TestForDeviceByModel:
         assert reg is not None
         assert reg.name == 'dehumidifier'
 
+    def test_ehs_via_ehs_token(self):
+        """A Samsung EHS air-to-water heat pump (TP1X_DA_AC_EHS_01001_0000)
+        shares the DA_AC_ board family with the room-AC models but reports
+        no oneUiVersion and carries the '_EHS_' (Eco Heating System) token
+        instead of '_RAC_'/'_PRAC_'/'_WAC_'/'_DHM_'; falls back to the
+        '_EHS_' token in modelNum."""
+        from custom_components.localthings.registry.by_type import for_device_by_model
+        reg = for_device_by_model(
+            'TP1X_DA_AC_EHS_01001_0000|10250141|60070105001711034A00010000002000',
+            'TP1X_DA_AC_EHS_01001_0000',
+        )
+        assert reg is not None
+        assert reg.name == 'ehs'
+
     def test_water_purifier_via_waterpurifier_token(self):
         """Issue #90: a water purifier (TP2X_WATERPURIFIER_20K) reports no
         oneUiVersion and no consumer-prefix match; falls back to the
@@ -703,22 +730,63 @@ class TestResolve:
         assert reg is not None
         assert reg.name == 'refrigerator'
 
-    def test_prefers_model_strings_over_resource_signature(self, all_device_fixtures):
-        """Every fixture with usable model strings resolves the same way
-        through `resolve` as through `for_device_by_model` directly."""
+    def test_prefers_resource_signatures_over_model_strings(self, all_device_fixtures):
+        """A strong live-resource signature wins over model metadata.
+
+        Across the fixture corpus Qooker is the only intentional disagreement:
+        its OVEN model token says oven while its /oven + MicroWave surface says
+        microwave. Locking the disagreement set keeps resource-first routing
+        from silently becoming greedy as new signatures or fixtures land.
+        """
         from custom_components.localthings.registry.by_type import (
-            resolve, for_device_by_model,
+            resolve, for_device_by_model, for_device_by_resources,
         )
+        disagreements = {}
         for name, resources in all_device_fixtures.items():
             info = resources.get('/information/vs/0', {})
+            by_resources = for_device_by_resources(resources)
             by_model = for_device_by_model(
                 info.get('x.com.samsung.da.modelNum', ''),
                 info.get('x.com.samsung.da.description', ''),
             )
-            if by_model is not None:
-                assert resolve(resources) is by_model, name
+            if by_resources is None or by_model is None:
+                continue
+            assert resolve(resources) is by_resources, name
+            if by_resources is not by_model:
+                disagreements[name] = (by_resources.name, by_model.name)
 
-    def test_falls_back_to_resource_signature(self, all_device_fixtures):
+        assert disagreements == {
+            'qooker_mw7500a': ('microwave', 'oven'),
+        }
+
+    def test_qooker_microwave_surface_overrides_generic_oven_oic_type(self):
+        """MW7500A declares oic.d.oven and carries an OVEN board token, but
+        its verified local API exposes MicroWave mode on an oven cavity. That
+        strong two-resource signature must win ahead of generic OIC metadata."""
+        from custom_components.localthings.registry.by_type import (
+            for_device_by_model,
+            for_device_by_oic_type,
+            for_device_by_resources,
+            resolve,
+        )
+        from tests.conftest import _load_device
+
+        resources = _load_device('qooker_mw7500a')
+        info = resources['/information/vs/0']
+        by_resources = for_device_by_resources(resources)
+        by_oic = for_device_by_oic_type(('oic.wk.d', 'oic.d.oven'))
+        by_model = for_device_by_model(
+            info['x.com.samsung.da.modelNum'],
+            info['x.com.samsung.da.description'],
+        )
+        reg = resolve(resources, device_types=('oic.wk.d', 'oic.d.oven'))
+
+        assert by_resources is not None and by_resources.name == 'microwave'
+        assert by_oic is not None and by_oic.name == 'oven'
+        assert by_model is not None and by_model.name == 'oven'
+        assert reg is by_resources
+
+    def test_resource_signature_types_dumps_without_information(self, all_device_fixtures):
         """The three dumps with no /information/vs/0 still type."""
         from custom_components.localthings.registry.by_type import resolve
         for name in ('cooktop', 'range_ne63a6511', 'range_no_info'):
@@ -825,3 +893,27 @@ class TestForDeviceByResources:
         assert reg is not None
         assert reg.name == 'microwave'
 
+    def test_microwave_mode_without_oven_cavity_is_not_matched(self):
+        """The mode vocabulary alone is too common to preempt metadata."""
+        from custom_components.localthings.registry.by_type import for_device_by_resources
+
+        resources = {
+            '/mode/vs/0': {
+                'x.com.samsung.da.supportedModes': ['MicroWave'],
+            },
+        }
+
+        assert for_device_by_resources(resources) is None
+
+    def test_scalar_supported_modes_is_not_a_microwave_signature(self):
+        """Malformed scalar data must not gain resource-first precedence."""
+        from custom_components.localthings.registry.by_type import for_device_by_resources
+
+        resources = {
+            '/mode/vs/0': {
+                'x.com.samsung.da.supportedModes': 'MicroWave',
+            },
+            '/oven/vs/0': {'x.com.samsung.da.state': 'Ready'},
+        }
+
+        assert for_device_by_resources(resources) is None

tests/test_ehs_capabilities.py

@@ -0,0 +1,199 @@
+"""Tests for Samsung EHS (Eco Heating System) heat pump support
+(TP1X_DA_AC_EHS_01001_0000).
+
+HA-free like the rest of the suite: exercises the registry, discovery/
+flatten, and the zone/dhw mode and temperature write contracts.
+"""
+from custom_components.localthings.registry.adapter import flatten
+from custom_components.localthings.registry.by_type import for_device_by_model
+from custom_components.localthings.registry.discovery import discover
+from custom_components.localthings.registry.entities import NumberDesc, SelectDesc, WaterHeaterDesc
+
+from tests.conftest import _load_device
+
+
+def _ehs():
+    resources = _load_device('ehs')
+    info = resources['/information/vs/0']
+    reg = for_device_by_model(
+        info['x.com.samsung.da.modelNum'], info['x.com.samsung.da.description'],
+    )
+    return reg, resources
+
+
+def _bound():
+    reg, resources = _ehs()
+    return discover(resources, reg.capabilities, reg.pattern_capabilities), resources
+
+
+def _state():
+    bound, resources = _bound()
+    return flatten(bound, resources)
+
+
+def _desc(key):
+    bound, _ = _bound()
+    return next(b.desc for b in bound if b.desc.key == key)
+
+
+def test_model_resolves_to_ehs_registry():
+    reg, _ = _ehs()
+    assert reg is not None and reg.name == 'ehs'
+
+
+def test_no_unbound_hrefs():
+    """Every resource in the real TP1X_DA_AC_EHS_01001_0000 dump binds or is
+    covered -- clears the coverage-gap repair a device_type='unknown' entry
+    raises."""
+    reg, resources = _ehs()
+    unbound = []
+    discover(resources, reg.capabilities, reg.pattern_capabilities, log=unbound.append)
+    assert unbound == []
+
+
+def test_expected_state_keys_present():
+    state = _state()
+    for key in ('zone_power', 'zone_mode', 'zone_temperature', 'zone_target_temperature',
+                'water_heater', 'away_mode', 'mute_once', 'alarm_code', 'energy_kwh'):
+        assert key in state, key
+
+
+def test_zone_temperature_reads_current_value():
+    state = _state()
+    assert state['zone_temperature'] == 30.0
+
+
+def test_zone_target_temperature_reads_desired_value():
+    state = _state()
+    assert state['zone_target_temperature'] == 5.0
+
+
+def test_zone_mode_reads_first_mode():
+    state = _state()
+    assert state['zone_mode'] == 'Cool'
+
+
+def test_zone_mode_select_options_come_from_live_supported_modes():
+    """Options are read live from x.com.samsung.da.supportedModes, not a
+    hardcoded tuple -- so a future firmware with a different mode set is
+    handled automatically."""
+    desc = _desc('zone_mode')
+    assert isinstance(desc, SelectDesc)
+    assert desc.options_field == 'x.com.samsung.da.supportedModes'
+    assert desc.options == ()
+
+
+def test_zone_mode_write_contract():
+    desc = _desc('zone_mode')
+    path, body = desc.write_fn('Heat', {})
+    assert path == ['mode', 'vs', '0']
+    assert body == {'x.com.samsung.da.modes': ['Heat']}
+
+
+def test_zone_power_reads_off():
+    state = _state()
+    assert state['zone_power'] is False
+
+
+def test_zone_power_write_contract():
+    desc = _desc('zone_power')
+    path, body = desc.write_fn('On', {})
+    assert path == ['power', 'vs', '0']
+    assert body == {'x.com.samsung.da.power': 'On'}
+
+
+def test_zone_target_temperature_write_contract():
+    desc = _desc('zone_target_temperature')
+    assert isinstance(desc, NumberDesc)
+    path, body = desc.write_fn('21.5', {})
+    assert path == ['temperatures', 'indoor', 'vs', '0']
+    assert body == {'x.com.samsung.da.desired': '21.5'}
+
+
+def test_zone_target_temperature_bounds_read_live():
+    """min/max/step come from the device's own resource fields rather than
+    a hardcoded constant -- see the adding-device-support skill's 'never
+    hard-code the one dump's values' section."""
+    desc = _desc('zone_target_temperature')
+    rep = {'x.com.samsung.da.minimum': '5.0', 'x.com.samsung.da.maximum': '25.0'}
+    assert desc.native_min_fn(rep) == 5.0
+    assert desc.native_max_fn(rep) == 25.0
+    assert desc.step_fn({'x.com.samsung.da.increment': '0.5'}) == 0.5
+    # No live field: falls back to a sane default rather than raising.
+    assert desc.native_min_fn({}) == 5.0
+    assert desc.native_max_fn({}) == 30.0
+    assert desc.step_fn({}) == 0.5
+
+
+def test_zone_target_temperature_bounds_fall_back_together():
+    """One end without the other is not a usable range: pairing a real
+    device minimum with an invented default maximum looks plausible and is
+    silently wrong, so a half-reported range falls back whole."""
+    desc = _desc('zone_target_temperature')
+    half = {'x.com.samsung.da.minimum': '10.0'}
+    assert desc.native_min_fn(half) == 5.0
+    assert desc.native_max_fn(half) == 30.0
+
+
+def test_zone_target_temperature_zero_increment_is_not_collapsed():
+    """`or` would turn a genuine 0 into the 0.5 default (issue #160)."""
+    desc = _desc('zone_target_temperature')
+    assert desc.step_fn({'x.com.samsung.da.increment': '0'}) == 0.0
+
+
+def test_water_heater_entity_is_bound():
+    """The composite water_heater entity binds the primary /mode/dhw/vs/0
+    resource -- same primary-plus-siblings shape as the AC's ClimateDesc
+    (see test_airconditioner_capabilities.py's test_climate_entity_is_bound)."""
+    bound, _ = _bound()
+    water_heaters = [b for b in bound if isinstance(b.desc, WaterHeaterDesc)]
+    assert len(water_heaters) == 1
+    assert water_heaters[0].href == '/mode/dhw/vs/0'
+
+
+def test_water_heater_reads_first_mode():
+    """The flattened/golden state exposes the same representative scalar
+    the entity's current_operation is derived from -- see climate.py's
+    _first_mode for the identical pattern on the AC side."""
+    state = _state()
+    assert state['water_heater'] == 'Eco'
+
+
+def test_water_heater_write_targets():
+    """DHW.entities[0].write_fn maps each (kind, value) command to the right
+    vendor POST target and body -- power, mode and temperature only, no fan/
+    swing/preset (the AC's climate.py has those; the DHW loop doesn't)."""
+    write = _desc('water_heater').write_fn
+    assert write(('power', True), {}) == (
+        ['power', 'dhw', 'vs', '0'], {'x.com.samsung.da.power': 'On'})
+    assert write(('power', False), {}) == (
+        ['power', 'dhw', 'vs', '0'], {'x.com.samsung.da.power': 'Off'})
+    assert write(('mode', 'Force'), {}) == (
+        ['mode', 'dhw', 'vs', '0'], {'x.com.samsung.da.modes': ['Force']})
+    assert write(('temperature', 45.0), {}) == (
+        ['temperatures', 'dhw', 'vs', '0'], {'x.com.samsung.da.desired': '45.0'})
+    assert write(('bogus', 1), {}) is None
+
+
+def test_dhw_power_and_temperature_declared_as_coverage():
+    """/power/dhw/vs/0 and /temperatures/dhw/vs/0 are read by the composite
+    water_heater entity (via water_heater.py's sibling reads), not given
+    their own entities -- declared as no-entity coverage caps so discover()
+    reports no gap, same pattern as the AC's CLIMATE_CONSUMED_HREFS."""
+    reg, _ = _ehs()
+    for href in ('/power/dhw/vs/0', '/temperatures/dhw/vs/0'):
+        caps = reg.capabilities.get(href)
+        assert caps, href
+        assert all(c.entities == () for c in caps), href
+
+
+def test_away_mode_reads_off():
+    state = _state()
+    assert state['away_mode'] is False
+
+
+def test_away_mode_write_contract():
+    desc = _desc('away_mode')
+    path, body = desc.write_fn('On', {})
+    assert path == ['option', 'outgoing', 'vs', '0']
+    assert body == {'x.com.samsung.da.away': 'On'}

tests/test_golden_regression.py

@@ -49,6 +49,18 @@ def test_registry_reproduces_golden_state_keys_for_washer():
     )
 
 
+def test_registry_reproduces_golden_state_keys_for_ehs():
+    from tests.conftest import _load_device
+    resources = _load_device('ehs')
+    golden = json.loads((GOLDEN / 'ehs.json').read_text())
+    state_keys = _new_state_keys('ehs', resources)
+    assert set(state_keys) == set(golden['state_keys']), (
+        f"state_keys mismatch:\n"
+        f"  extra:   {sorted(set(state_keys) - set(golden['state_keys']))}\n"
+        f"  missing: {sorted(set(golden['state_keys']) - set(state_keys))}"
+    )
+
+
 def test_registry_reproduces_golden_state_keys_for_washer_wa8000t():
     """Top-load washer (WA8000T, issue #106) reports no oneUiVersion and
     used the 'WA' consumer-model prefix, previously unmapped in
@@ -686,6 +698,22 @@ def test_registry_reproduces_golden_state_keys_for_microwave_mw7300b():
     )
 
 
+def test_registry_reproduces_golden_state_keys_for_qooker_mw7500a():
+    """Bespoke Qooker MW7500A uses Samsung's OVEN board/type metadata but
+    proves its microwave semantics through MicroWave mode plus cavity
+    powerLevel. The routing correction must expose microwave state keys
+    without the misleading oven_mode/oven_state entities."""
+    from tests.conftest import _load_device
+    resources = _load_device('qooker_mw7500a')
+    golden = json.loads((GOLDEN / 'qooker_mw7500a.json').read_text())
+    state_keys = _new_state_keys('qooker_mw7500a', resources)
+    assert set(state_keys) == set(golden['state_keys']), (
+        f"state_keys mismatch:\n"
+        f"  extra:   {sorted(set(state_keys) - set(golden['state_keys']))}\n"
+        f"  missing: {sorted(set(golden['state_keys']) - set(state_keys))}"
+    )
+
+
 def test_registry_reproduces_golden_state_keys_for_microwave_me7500d():
     """TP1X_DA-KS-MICROWAVE-01051 plain microwave (model ME7500D, issues
     #137/#142) -- the same microwave registry as MW7300B above, but this

tests/test_microwave_capabilities.py

@@ -1,6 +1,9 @@
 """Unit tests for the microwave-family capabilities (issue #121/#66 split
 into their own device type instead of being folded into oven.py)."""
-from custom_components.localthings.registry.by_type import for_device_by_model
+from custom_components.localthings.registry.by_type import (
+    for_device_by_model,
+    resolve,
+)
 from custom_components.localthings.registry.capabilities import microwave
 from custom_components.localthings.registry.discovery import discover
 
@@ -39,6 +42,27 @@ def test_microwave_hood_fan_fixture_resolves_and_has_no_unbound_hrefs():
     assert unbound == []
 
 
+def test_qooker_fixture_resolves_as_microwave_and_has_no_unbound_hrefs():
+    """Bespoke Qooker MW7500A is microwave-shaped despite both its OCF type
+    and internal board token saying oven."""
+    from tests.conftest import _load_device
+    resources = _load_device('qooker_mw7500a')
+
+    reg = resolve(resources, device_types=('oic.wk.d', 'oic.d.oven'))
+
+    assert reg is not None
+    assert reg.name == 'microwave'
+    unbound = []
+    bound = discover(
+        resources, reg.capabilities, reg.pattern_capabilities,
+        log=unbound.append,
+    )
+    assert unbound == []
+    keys = {entity.desc.key for entity in bound}
+    assert {'cooking_mode', 'power_level', 'setpoint'} <= keys
+    assert 'oven_mode' not in keys
+
+
 # ---------------------------------------------------------------------------
 # MICROWAVE_SETPOINT — NumberDesc with RMW write semantics
 # ---------------------------------------------------------------------------

tests/test_onebody_washer_subdevice.py

@@ -0,0 +1,92 @@
+"""Pattern C subdevice discovery: AWM-WW-AID-26-ONEBODY washer+dryer combo
+(issue #241).
+
+The fixture is a live capture from the reporting board (see its
+`seeds_note`): the master tree is the dryer (`oic.d.dryer`,
+`..._DV80H27H`), and a complete washer tree (`..._WF80H`) answers at
+`/<uuid>/device/0`, where the UUID appears *only* as the path prefix of the
+`x.com.samsung.da.multidevice` link in `/oic/res` -- no `subdeviceIdList`
+(Pattern B's signal), no `/device/<n>` sibling (Pattern A's).
+"""
+from tests.conftest import FakeCoapSession, _discover_full, _load_device_full
+
+FIXTURE = 'washer_dryer_onebody_awm'
+WASHER_UUID = '58b7d338-15c5-97d3-b562-000000000001'
+
+
+def _discover():
+    resources, oic_res, seeds = _load_device_full(FIXTURE)
+    return _discover_full(resources, oic_res, seeds)
+
+
+def test_washer_subdevice_materializes_from_oic_res_uuid_link():
+    bound, materialized, skipped, full_resources, device_type_name = _discover()
+
+    assert [s.key for s in materialized] == [WASHER_UUID]
+    sub = materialized[0]
+    assert sub.kind == 'prefixed'
+    assert sub.seed_path == (WASHER_UUID, 'device', '0')
+    # Collection mode, not the issue-#205 flat fallback.
+    assert sub.flat_hrefs == ()
+
+
+def test_washer_subdevice_probe_only_fires_for_the_advertised_uuid():
+    """Pattern C must not invent candidates: exactly one prefixed seed is
+    probed (the UUID from the /oic/res multidevice link), alongside the
+    bounded speculative Pattern A probes this board 4.04s."""
+    from custom_components.localthings.registry.subdevices import (
+        enumerate_subdevices,
+    )
+
+    resources, oic_res, seeds = _load_device_full(FIXTURE)
+    probes: dict[str, bool] = {}
+    sess = FakeCoapSession(seeds)
+    candidates, _extra = enumerate_subdevices(
+        sess, resources, oic_res, probe_log=probes.__setitem__,
+    )
+
+    assert probes[f'/{WASHER_UUID}/device/0'] is True
+    assert probes['/device/1'] is False
+    assert probes['/device/2'] is False
+    # No flat-fallback flood: the seed Collection answered, so no per-href
+    # probes under the prefix beyond the seed itself.
+    prefixed_probes = [h for h in probes if h.startswith(f'/{WASHER_UUID}/')]
+    assert prefixed_probes == [f'/{WASHER_UUID}/device/0']
+    assert [c.key for c in candidates] == [WASHER_UUID]
+
+
+def test_washer_subdevice_binds_its_own_primary_entities():
+    """The washer tree carries its own /operational/state and /power -- the
+    liveness gate must see live primary entities, and the bound set must
+    carry washer-side keys under the subdevice key prefix."""
+    bound, materialized, _skipped, _full, _name = _discover()
+    sub = materialized[0]
+
+    sub_keys = {b.desc.key for b in bound if b.subdevice.key == sub.key}
+    assert sub_keys, 'washer subdevice bound no entities at all'
+    # Its own operational state and its own power switch/sensor -- the two
+    # things SmartThings cloud splits this unit over.
+    assert any('machine_state' in k for k in sub_keys), sub_keys
+    assert any('power' in k for k in sub_keys), sub_keys
+
+
+def test_master_dryer_entities_unchanged_by_washer_discovery():
+    """Additive only: the master (dryer) side must keep binding the same
+    entity keys with and without the washer candidate materializing."""
+    resources, _oic_res, _seeds = _load_device_full(FIXTURE)
+
+    # Without any subdevices (oic_res withheld, seeds empty -> washer never
+    # discovered).
+    bound_solo, materialized_solo, _s, _f, _n = _discover_full(
+        resources, [], {},
+    )
+    assert materialized_solo == []
+    solo_keys = {(b.href, b.desc.key) for b in bound_solo}
+
+    bound, materialized, _s2, _f2, _n2 = _discover()
+    sub = materialized[0]
+    main_keys = {
+        (b.href, b.desc.key) for b in bound if b.subdevice.key != sub.key
+    }
+
+    assert main_keys == solo_keys

tests/test_subdevices.py

@@ -451,6 +451,45 @@ def test_enumerate_both_patterns_checked_independently():
     ]
 
 
+def test_enumerate_prefixed_id_named_by_both_subdevice_id_list_and_oic_res_is_not_duplicated():
+    """A board can carry a UUID that is both listed in subdeviceIdList
+    (Pattern B's signal) *and* advertised as an /oic/res link prefix
+    (Pattern C's) -- the TP2X_FAC_BORA_21K reporter's own board does this.
+    The two signals must resolve to one candidate, not two."""
+    resources = {
+        '/subdevices/vs/0': {'x.com.samsung.da.subdeviceIdList': [_UUID]},
+    }
+    oic_res = [{'di': 'a', 'links': [
+        {'href': f'/{_UUID}/multidevice/vs/0'},
+    ]}]
+    sess = _FakeSession({
+        (_UUID, 'device', '0'): [_DEVCOL_REP, {'href': '/mode/vs/0', 'rep': {'m': 1}}],
+    })
+    subdevices, _extra = enumerate_subdevices(sess, resources, oic_res)
+    assert [(u.kind, u.key) for u in subdevices] == [('prefixed', _UUID)]
+
+
+def test_enumerate_prefixed_id_case_mismatch_between_sources_is_not_duplicated():
+    """subdeviceIdList and an /oic/res link prefix can name the same UUID
+    with different casing -- the match must be case-insensitive, or the
+    same physical subdevice materializes twice under two different keys."""
+    upper_uuid = _UUID.upper()
+    resources = {
+        '/subdevices/vs/0': {'x.com.samsung.da.subdeviceIdList': [upper_uuid]},
+    }
+    oic_res = [{'di': 'a', 'links': [
+        {'href': f'/{_UUID}/multidevice/vs/0'},
+    ]}]
+    sess = _FakeSession({
+        (upper_uuid, 'device', '0'): [_DEVCOL_REP, {'href': '/mode/vs/0', 'rep': {'m': 1}}],
+        (_UUID, 'device', '0'): [_DEVCOL_REP, {'href': '/mode/vs/0', 'rep': {'m': 1}}],
+    })
+    subdevices, _extra = enumerate_subdevices(sess, resources, oic_res)
+    assert len(subdevices) == 1
+    assert subdevices[0].kind == 'prefixed'
+    assert subdevices[0].key.lower() == _UUID
+
+
 # ---------------------------------------------------------------------------
 # discover_partitioned
 # ---------------------------------------------------------------------------

tests/test_translations.py

@@ -129,7 +129,17 @@ def test_no_catalog_carries_unresolved_core_references():
 # so it presents as the device itself, and never reads a catalog name. Same
 # for the ARTIK051 air-purifier's airflow_fan (issue #56) -- ordered speed
 # levels, no presets, same _attr_name = None treatment.
-UNNAMED_DESCRIPTORS = {("fan", "fan"), ("fan", "airflow_fan")}
+#
+# The EHS DHW water_heater is deliberately NOT in here: it is one loop of a
+# two-loop device rather than the device itself, so it carries a catalog
+# name like everything else (entity.water_heater.dhw, via the descriptor's
+# translation_key). That is independent of its *states* -- those are all
+# HA's own standard water_heater states (STATE_ECO/HEAT_PUMP/HIGH_DEMAND/
+# PERFORMANCE/OFF), which Home Assistant translates itself via the
+# entity_component fallback, so no per-state entry is needed either way.
+UNNAMED_DESCRIPTORS = {
+    ("fan", "fan"), ("fan", "airflow_fan"),
+}
 
 
 def test_every_descriptor_has_an_entity_catalog_entry():

tests/test_water_heater_ehs.py

@@ -0,0 +1,212 @@
+"""HA water_heater-entity mapping tests for the EHS DHW loop."""
+
+from homeassistant.components.water_heater import (
+    STATE_ECO,
+    STATE_HEAT_PUMP,
+    STATE_HIGH_DEMAND,
+    STATE_PERFORMANCE,
+    WaterHeaterEntity,
+)
+from homeassistant.const import STATE_OFF, UnitOfTemperature
+
+from custom_components.localthings.registry.by_type import ehs
+from custom_components.localthings.registry.discovery import discover
+from custom_components.localthings.registry.entities import WaterHeaterDesc
+from custom_components.localthings.water_heater import LocalThingsWaterHeater
+from tests.conftest import _load_device
+
+
+class _FakeCoordinator:
+    device_serial = 'TEST-EHS-SERIAL'
+    device_info = {}
+    data = {}
+
+    def __init__(self, resources):
+        self.last_resources = resources
+        self.commands = []
+
+    def resource(self, href):
+        return self.last_resources.get(href, {})
+
+    def canonical_resources(self, subdevice):
+        # Every bound entity in this test uses the default MAIN subdevice,
+        # so the canonical view is just the raw snapshot (issue #177 --
+        # see LocalThingsEntity._resources).
+        return self.last_resources
+
+    async def async_send_command(self, bound, payload):
+        self.commands.append((bound, payload))
+
+
+def _entity(resources, coordinator=None):
+    bound = discover(
+        resources, ehs.REGISTRY.capabilities, ehs.REGISTRY.pattern_capabilities,
+    )
+    water_heater_bound = next(item for item in bound if isinstance(item.desc, WaterHeaterDesc))
+    return LocalThingsWaterHeater(coordinator or _FakeCoordinator(resources), water_heater_bound)
+
+
+def test_current_operation_reads_eco_when_on():
+    entity = _entity(_load_device('ehs'))
+    assert entity.current_operation == STATE_ECO
+
+
+def test_current_operation_is_off_when_powered_off():
+    resources = _load_device('ehs')
+    resources['/power/dhw/vs/0']['x.com.samsung.da.power'] = 'Off'
+    entity = _entity(resources)
+    assert entity.current_operation == STATE_OFF
+
+
+def test_operation_list_includes_off_and_mapped_modes():
+    """Fixture's supportedModes is Eco/Std/Power/Force -- all four map onto
+    HA's own standard water_heater states (see water_heater.py's module
+    docstring for the SmartThings-cloud precedent this mirrors)."""
+    entity = _entity(_load_device('ehs'))
+    assert entity.operation_list == [
+        STATE_OFF, STATE_ECO, STATE_HEAT_PUMP, STATE_PERFORMANCE, STATE_HIGH_DEMAND,
+    ]
+
+
+def test_temperature_reads_current_and_target():
+    entity = _entity(_load_device('ehs'))
+    assert entity.current_temperature == 38.0
+    assert entity.target_temperature == 40.0
+    assert entity.temperature_unit == UnitOfTemperature.CELSIUS
+    assert entity.min_temp == 40.0
+    assert entity.max_temp == 62.0
+    assert entity.target_temperature_step == 0.5
+
+
+def test_temperature_bounds_fall_back_together():
+    """A board reporting only one end of the range must not pair a real
+    device bound with an HA default -- both ends or neither, same rule as
+    climate._range()."""
+    resources = _load_device('ehs')
+    del resources['/temperatures/dhw/vs/0']['x.com.samsung.da.maximum']
+    entity = _entity(resources)
+
+    # Neither end comes from the device: the device minimum (40.0) is
+    # dropped along with the missing maximum, so both fall back to HA's own
+    # water_heater defaults rather than being mixed.
+    assert entity.min_temp != 40.0
+    assert (entity.min_temp, entity.max_temp) == (
+        WaterHeaterEntity.min_temp.fget(entity),
+        WaterHeaterEntity.max_temp.fget(entity),
+    )
+
+
+def test_zero_increment_is_not_collapsed_into_the_default():
+    """`or` would turn a genuine 0 into 0.5 (issue #160)."""
+    resources = _load_device('ehs')
+    resources['/temperatures/dhw/vs/0']['x.com.samsung.da.increment'] = '0'
+    entity = _entity(resources)
+
+    assert entity.target_temperature_step == 0.0
+
+
+def test_current_operation_tolerates_lowercase_device_codes():
+    resources = _load_device('ehs')
+    resources['/mode/dhw/vs/0']['x.com.samsung.da.modes'] = ['eco']
+    entity = _entity(resources)
+
+    assert entity.current_operation == STATE_ECO
+
+
+def test_entity_is_named_rather_than_taking_the_device_name():
+    """Unlike climate.py's AC, DHW is one loop of a two-loop device, so it
+    takes a catalog name instead of presenting as the device itself."""
+    entity = _entity(_load_device('ehs'))
+
+    # No _attr_name override (that would present as the bare device name,
+    # and would also beat the catalog); the name comes from the catalog key.
+    assert '_attr_name' not in entity.__dict__
+    assert entity.translation_key == 'dhw'
+
+
+async def test_set_temperature_writes_dhw_temperature():
+    resources = _load_device('ehs')
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_temperature(temperature=45.0)
+
+    assert coordinator.commands == [(entity._bound, ('temperature', 45.0))]
+
+
+async def test_set_temperature_honours_operation_mode():
+    """water_heater.set_temperature carries an optional operation_mode
+    (SET_TEMPERATURE_SCHEMA); dropping it would move the setpoint without
+    ever changing mode -- same bug fixed for climate's hvac_mode."""
+    resources = _load_device('ehs')
+    resources['/power/dhw/vs/0']['x.com.samsung.da.power'] = 'Off'
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_temperature(temperature=55.0,
+                                       operation_mode=STATE_HIGH_DEMAND)
+
+    assert coordinator.commands == [
+        (entity._bound, ('power', True)),
+        (entity._bound, ('mode', 'Force')),
+        (entity._bound, ('temperature', 55.0)),
+    ]
+
+
+async def test_set_temperature_with_off_mode_skips_the_setpoint_write():
+    resources = _load_device('ehs')
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_temperature(temperature=55.0, operation_mode=STATE_OFF)
+
+    assert coordinator.commands == [(entity._bound, ('power', False))]
+
+
+async def test_turn_on_and_off_write_dhw_power():
+    resources = _load_device('ehs')
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_turn_on()
+    await entity.async_turn_off()
+
+    assert coordinator.commands == [
+        (entity._bound, ('power', True)),
+        (entity._bound, ('power', False)),
+    ]
+
+
+async def test_set_operation_mode_off_turns_off_without_writing_mode():
+    resources = _load_device('ehs')
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_operation_mode(STATE_OFF)
+
+    assert coordinator.commands == [(entity._bound, ('power', False))]
+
+
+async def test_set_operation_mode_writes_mapped_device_code():
+    resources = _load_device('ehs')
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_operation_mode(STATE_HIGH_DEMAND)
+
+    # DHW power is already on (fixture default) -- no extra power write.
+    assert coordinator.commands == [(entity._bound, ('mode', 'Force'))]
+
+
+async def test_set_operation_mode_powers_on_first_when_off():
+    resources = _load_device('ehs')
+    resources['/power/dhw/vs/0']['x.com.samsung.da.power'] = 'Off'
+    coordinator = _FakeCoordinator(resources)
+    entity = _entity(resources, coordinator)
+
+    await entity.async_set_operation_mode(STATE_PERFORMANCE)
+
+    assert coordinator.commands == [
+        (entity._bound, ('power', True)),
+        (entity._bound, ('mode', 'Power')),
+    ]