Allow a climate entity to have an independent on / off state attribute

homeassistant/components/climate/__init__.py

@@ -240,6 +240,7 @@ CACHED_PROPERTIES_WITH_ATTR_ = {
     "preset_mode",
     "preset_modes",
     "is_aux_heat",
+    "is_on",
     "fan_mode",
     "fan_modes",
     "swing_mode",
@@ -280,6 +281,7 @@ class ClimateEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
     _attr_hvac_mode: HVACMode | None
     _attr_hvac_modes: list[HVACMode]
     _attr_is_aux_heat: bool | None
+    _attr_is_on: bool | None
     _attr_max_humidity: float = DEFAULT_MAX_HUMIDITY
     _attr_max_temp: float
     _attr_min_humidity: float = DEFAULT_MIN_HUMIDITY
@@ -357,6 +359,26 @@ class ClimateEntity(Entity, cached_properties=CACHED_PROPERTIES_WITH_ATTR_):
             return HVACMode(hvac_mode).value  # type: ignore[unreachable]
         return hvac_mode.value
 
+    @property
+    def is_on(self) -> bool | None:
+        """Return True if the climate is turned on.
+
+        The climate's on/off state can be be controlled independently
+        from the hvac_action and hvac_mode if the _attr_is_on attribute is set.
+
+        If the _attr_is_on attrubiute is set, then return that value.
+        Otherwise, return True if hvac_action is not None and not HVACAction.OFF.
+        Return None if hvac_action is None,
+        otherwise return True if hvac_mode is not HVACMode.OFF.
+        """
+        if hasattr(self, "_attr_is_on"):
+            return self._attr_is_on
+        if self.hvac_action is not None:
+            return self.hvac_action != HVACAction.OFF
+        if self.hvac_mode is None:
+            return None
+        return self.hvac_mode != HVACMode.OFF
+
     @property
     def precision(self) -> float:
         """Return the precision of the system."""

tests/components/climate/test_init.py

@@ -36,6 +36,7 @@ from homeassistant.components.climate.const import (
     SWING_HORIZONTAL_OFF,
     SWING_HORIZONTAL_ON,
     ClimateEntityFeature,
+    HVACAction,
 )
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import ATTR_TEMPERATURE, PRECISION_WHOLE, UnitOfTemperature
@@ -425,7 +426,7 @@ async def test_mode_validation(
 
 
 async def test_turn_on_off_toggle(hass: HomeAssistant) -> None:
-    """Test turn_on/turn_off/toggle methods."""
+    """Test turn_on/turn_off/toggle methods and the is_on property."""
 
     class MockClimateEntityTest(MockClimateEntity):
         """Mock Climate device."""
@@ -440,20 +441,54 @@ async def test_turn_on_off_toggle(hass: HomeAssistant) -> None:
         async def async_set_hvac_mode(self, hvac_mode: HVACMode) -> None:
             """Set new target hvac mode."""
             self._attr_hvac_mode = hvac_mode
+            self._attr_is_on = hvac_mode != HVACMode.OFF
 
     climate = MockClimateEntityTest()
     climate.hass = hass
 
+    assert climate.is_on is False
+
     await climate.async_turn_on()
     assert climate.hvac_mode == HVACMode.HEAT
+    assert climate.is_on is True
 
     await climate.async_turn_off()
     assert climate.hvac_mode == HVACMode.OFF
+    assert climate.is_on is False
 
     await climate.async_toggle()
     assert climate.hvac_mode == HVACMode.HEAT
+    assert climate.is_on is True
     await climate.async_toggle()
     assert climate.hvac_mode == HVACMode.OFF
+    assert climate.is_on is False
+
+    # Test is_on property in case _attr_is_on is not set
+    delattr(climate, "_attr_is_on")
+
+    # When hvac_action is set, is_on should depend on it
+    climate._attr_hvac_mode = HVACMode.AUTO
+    climate._attr_hvac_action = HVACAction.HEATING
+    assert climate.hvac_mode == HVACMode.AUTO
+    assert climate.hvac_action == HVACAction.HEATING
+    assert climate.is_on is True
+    climate._attr_hvac_action = HVACAction.OFF
+    assert climate.hvac_action == HVACAction.OFF
+    assert climate.is_on is False
+
+    # When hvac_action is not used and hvac_mode is set, is_on should depend on it
+    climate._attr_hvac_action = None
+    assert climate.hvac_action is None
+    assert climate.hvac_mode == HVACMode.AUTO
+    assert climate.is_on is True
+    climate._attr_hvac_mode = HVACMode.OFF
+    assert climate.hvac_mode == HVACMode.OFF
+    assert climate.is_on is False
+
+    # If no mode or action is set and _attr_is_on is not set, is_on should be None
+    climate._attr_hvac_action = None
+    climate._attr_hvac_mode = None
+    assert climate.is_on is None
 
 
 async def test_sync_toggle(hass: HomeAssistant) -> None: