Add hvac_action support to melcloud

Since actions are shared between water tank (if any) and climate device,
hvac action can be idle even when heat pump is active

homeassistant/components/melcloud/climate.py

@@ -20,6 +20,7 @@
     DEFAULT_MIN_TEMP,
     ClimateEntity,
     ClimateEntityFeature,
+    HVACAction,
     HVACMode,
 )
 from homeassistant.config_entries import ConfigEntry
@@ -60,6 +61,18 @@
 }
 ATW_ZONE_HVAC_MODE_REVERSE_LOOKUP = {v: k for k, v in ATW_ZONE_HVAC_MODE_LOOKUP.items()}
 
+ATW_ZONE_HVAC_ACTION_LOOKUP = {
+    atw.STATUS_IDLE: HVACAction.IDLE,
+    atw.STATUS_HEAT_ZONES: HVACAction.HEATING,
+    atw.STATUS_COOL: HVACAction.COOLING,
+    atw.STATUS_STANDBY: HVACAction.IDLE,
+    # Heating water tank, so the zone is idle
+    atw.STATUS_HEAT_WATER: HVACAction.IDLE,
+    atw.STATUS_LEGIONELLA: HVACAction.IDLE,
+    # Heat pump cannot heat in this mode, but will be ready soon
+    atw.STATUS_DEFROST: HVACAction.PREHEATING,
+}
+
 
 async def async_setup_entry(
     hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
@@ -351,6 +364,13 @@ def hvac_modes(self) -> list[HVACMode]:
         """Return the list of available hvac operation modes."""
         return [self.hvac_mode]
 
+    @property
+    def hvac_action(self) -> HVACAction | None:
+        """Return the current running hvac operation."""
+        if not self._device.power:
+            return HVACAction.OFF
+        return ATW_ZONE_HVAC_ACTION_LOOKUP.get(self._device.status)
+
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""