diff --git a/custom_components/localthings/registry/capabilities/airconditioner.py b/custom_components/localthings/registry/capabilities/airconditioner.py
index b502a63..93b96bf 100644
--- a/custom_components/localthings/registry/capabilities/airconditioner.py
+++ b/custom_components/localthings/registry/capabilities/airconditioner.py
@@ -384,6 +384,21 @@ def _has_option_token_any_board(prefix):
     return lambda rep, resources: _option_token(rep, prefix) is not None
 
 
+def _reports_celsius(resources):
+    """Whether this subdevice's own /temperatures/vs/0 declares Celsius (or
+    says nothing at all, `_temps_vs_unit`'s default).
+
+    Guards `OutdoorTemp_`'s -55 offset below: issue #367's field validation
+    (48h against weather.forecast_home, r=0.92) ran on Celsius-locale boards
+    only -- 13 of the 14 non-legacy fixtures that carry the token declare
+    Celsius, and the offset's own calibration comment is a Celsius reading
+    too. The one Fahrenheit-locale exception on record
+    (`airconditioner_lnx_rac_heatpump`) has nothing to confirm the same
+    additive constant, or degrees C rather than F, still hold -- so this
+    stays off boards that declare anything else, rather than guess."""
+    return _temps_vs_unit(resources.get(HREF_TEMPS_VS) or {}) == "°C"
+
+
 def _option_token_on(prefix):
     return lambda rep: _option_token(rep, prefix) == "On"
 
@@ -795,13 +810,14 @@ CLIMATE = Capability(
         # Outdoor temperature, offset by 55 -- calibrated against an
         # independent thermometer (token 75 while it read 20.3°C).
         #
-        # exists_fn is token-presence-only (issue #367): the token was
-        # previously gated behind is_legacy_board for no reason tied to the
-        # token itself, which silently dropped the sensor on every
-        # non-legacy board that reports it -- 14 of 17 fixtures carrying the
-        # token in the issue's own survey. A 48h/289-sample field capture
-        # correlated it against weather.forecast_home at r=0.92, ruling out
-        # a firmware constant.
+        # exists_fn is token-presence-only (issue #367), not is_legacy_board:
+        # gating it there dropped the sensor on every non-legacy board that
+        # reports it -- 14 of 17 fixtures carrying the token in the issue's
+        # own survey. A 48h/289-sample field capture correlated it against
+        # weather.forecast_home at r=0.92, ruling out a firmware constant.
+        # `_reports_celsius` keeps that presence check from also claiming
+        # the -55 Celsius offset for board generations it was never
+        # validated on -- see its own docstring.
         #
         # enabled_default=False: multi-split installs (multiple indoor heads
         # on one outdoor condenser) report the same token on every head, so
@@ -813,7 +829,10 @@ CLIMATE = Capability(
         SensorDesc(
             key="outdoor_temperature",
             rep_fn=_option_token_num("OutdoorTemp", offset=55),
-            exists_fn=_has_option_token_any_board("OutdoorTemp"),
+            exists_fn=lambda rep, resources: (
+                _has_option_token_any_board("OutdoorTemp")(rep, resources)
+                and _reports_celsius(resources)
+            ),
             device_class="temperature",
             state_class="measurement",
             unit="°C",
diff --git a/tests/fixtures/golden/airconditioner_lnx_rac_heatpump.json b/tests/fixtures/golden/airconditioner_lnx_rac_heatpump.json
index 1264892..9cbc8d2 100644
--- a/tests/fixtures/golden/airconditioner_lnx_rac_heatpump.json
+++ b/tests/fixtures/golden/airconditioner_lnx_rac_heatpump.json
@@ -22,7 +22,6 @@
     "mute_once",
     "odor_controller_active",
     "odor_controller_progress",
-    "outdoor_temperature",
     "power_watts",
     "tropical_night_mode"
   ]
diff --git a/tests/test_airconditioner_capabilities.py b/tests/test_airconditioner_capabilities.py
index 023a24a..49e7526 100644
--- a/tests/test_airconditioner_capabilities.py
+++ b/tests/test_airconditioner_capabilities.py
@@ -654,6 +654,22 @@ def test_lnx_rac_heatpump_no_unbound_hrefs():
     assert unbound == []
 
 
+def test_lnx_rac_heatpump_outdoor_temperature_stays_off_fahrenheit_boards():
+    """issue #367's -55 offset was field-validated on Celsius-locale boards
+    only; this fixture's own /temperatures/vs/0 declares Fahrenheit despite
+    carrying an OutdoorTemp_ token, so the sensor stays off rather than
+    apply an unvalidated offset/unit to it (see _reports_celsius)."""
+    reg, resources = _ac_lnx_rac_heatpump()
+    temps_item = resources["/temperatures/vs/0"]["x.com.samsung.da.items"][0]
+    assert temps_item["x.com.samsung.da.unit"] == "Fahrenheit"
+    options = resources["/mode/vs/0"]["x.com.samsung.da.options"]
+    assert any(o.startswith("OutdoorTemp_") for o in options)
+
+    bound = discover(resources, reg.capabilities, reg.pattern_capabilities)
+    state = flatten(bound, resources)
+    assert "outdoor_temperature" not in state
+
+
 def test_lnx_rac_heatpump_absence_power_saving_state():
     reg, resources = _ac_lnx_rac_heatpump()
     bound = discover(resources, reg.capabilities, reg.pattern_capabilities)