From 1cdf874d0763e730bcf55c915522eb9f3ea2e808 Mon Sep 17 00:00:00 2001
From: Erwin Douna <e.douna@gmail.com>
Date: Wed, 30 Sep 2026 17:05:01 +0200
Subject: [PATCH] Add HVAC action to MELCloud Home ATW zones (#183771)

---
 .../components/melcloud_home/climate.py       | 21 +++++++++
 .../melcloud_home/snapshots/test_climate.ambr |  2 +
 .../components/melcloud_home/test_climate.py  | 43 +++++++++++++++++++
 3 files changed, 66 insertions(+)

diff --git a/homeassistant/components/melcloud_home/climate.py b/homeassistant/components/melcloud_home/climate.py
index c65aa18f85cb..f2f8cff92436 100644
--- a/homeassistant/components/melcloud_home/climate.py
+++ b/homeassistant/components/melcloud_home/climate.py
@@ -7,6 +7,7 @@ from aiomelcloudhome import (
     ATAOperationMode,
     ATAVaneHorizontal,
     ATAVaneVertical,
+    ATWOperationMode,
     ATWZoneMode,
 )
 
@@ -14,6 +15,7 @@ from homeassistant.components.climate import (
     ClimateEntity,
     ClimateEntityDescription,
     ClimateEntityFeature,
+    HVACAction,
     HVACMode,
 )
 from homeassistant.const import ATTR_TEMPERATURE, UnitOfTemperature
@@ -92,6 +94,15 @@ HVAC_MODE_TO_ATW_ZONE_MODE: dict[HVACMode, ATWZoneMode] = {
     HVACMode.COOL: ATWZoneMode.COOL_ROOM_TEMPERATURE,
 }
 
+# The unit heats either the tank or the zones, so heating the tank idles the zones
+ATW_OPERATION_TO_HVAC_ACTION: dict[ATWOperationMode, HVACAction] = {
+    ATWOperationMode.STOP: HVACAction.IDLE,
+    ATWOperationMode.HOT_WATER: HVACAction.IDLE,
+    ATWOperationMode.HEAT: HVACAction.HEATING,
+    ATWOperationMode.HEAT_ZONES: HVACAction.HEATING,
+    ATWOperationMode.COOL: HVACAction.COOLING,
+}
+
 
 async def async_setup_entry(
     hass: HomeAssistant,
@@ -441,6 +452,16 @@ class ATWZoneClimateEntity(MelCloudHomeATWZoneEntity, ClimateEntity):
             else HVACMode.OFF
         )
 
+    @property
+    @override
+    def hvac_action(self) -> HVACAction | None:
+        """Return what the unit is doing for this zone."""
+        if self.hvac_mode == HVACMode.OFF:
+            return HVACAction.OFF
+        if self.unit.operation_mode is None:
+            return None
+        return ATW_OPERATION_TO_HVAC_ACTION[self.unit.operation_mode]
+
     @override
     async def async_set_hvac_mode(self, hvac_mode: HVACMode) -> None:
         """Set the HVAC mode."""
diff --git a/tests/components/melcloud_home/snapshots/test_climate.ambr b/tests/components/melcloud_home/snapshots/test_climate.ambr
index 526c0c4e2366..b374b798c416 100644
--- a/tests/components/melcloud_home/snapshots/test_climate.ambr
+++ b/tests/components/melcloud_home/snapshots/test_climate.ambr
@@ -49,6 +49,7 @@
     'attributes': ReadOnlyDict({
       <ClimateEntityStateAttribute.CURRENT_TEMPERATURE: 'current_temperature'>: 20.0,
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Heat Pump Zone 1',
+      <ClimateEntityStateAttribute.HVAC_ACTION: 'hvac_action'>: <HVACAction.HEATING: 'heating'>,
       <ClimateEntityCapabilityAttribute.HVAC_MODES: 'hvac_modes'>: list([
         <HVACMode.OFF: 'off'>,
         <HVACMode.HEAT: 'heat'>,
@@ -117,6 +118,7 @@
     'attributes': ReadOnlyDict({
       <ClimateEntityStateAttribute.CURRENT_TEMPERATURE: 'current_temperature'>: 21.0,
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Heat Pump Zone 2',
+      <ClimateEntityStateAttribute.HVAC_ACTION: 'hvac_action'>: <HVACAction.HEATING: 'heating'>,
       <ClimateEntityCapabilityAttribute.HVAC_MODES: 'hvac_modes'>: list([
         <HVACMode.OFF: 'off'>,
         <HVACMode.HEAT: 'heat'>,
diff --git a/tests/components/melcloud_home/test_climate.py b/tests/components/melcloud_home/test_climate.py
index c655409fe7ba..bd155257a35b 100644
--- a/tests/components/melcloud_home/test_climate.py
+++ b/tests/components/melcloud_home/test_climate.py
@@ -19,6 +19,7 @@ import pytest
 
 from homeassistant.components.climate import (
     ATTR_FAN_MODE,
+    ATTR_HVAC_ACTION,
     ATTR_HVAC_MODE,
     ATTR_SWING_HORIZONTAL_MODE,
     ATTR_SWING_MODE,
@@ -28,6 +29,7 @@ from homeassistant.components.climate import (
     SERVICE_SET_SWING_HORIZONTAL_MODE,
     SERVICE_SET_SWING_MODE,
     SERVICE_SET_TEMPERATURE,
+    HVACAction,
     HVACMode,
 )
 from homeassistant.components.melcloud_home.const import DOMAIN
@@ -527,6 +529,47 @@ async def test_atw_zone_temperature_range(
     assert state2.attributes["max_temp"] == 28.0
 
 
+@pytest.mark.parametrize(
+    ("overrides", "expected_action"),
+    [
+        pytest.param({"OperationMode": "Stop"}, HVACAction.IDLE, id="idle"),
+        pytest.param({"OperationMode": "HotWater"}, HVACAction.IDLE, id="hot_water"),
+        pytest.param({"OperationMode": "Heat"}, HVACAction.HEATING, id="heat"),
+        pytest.param(
+            {"OperationMode": "HeatZones"}, HVACAction.HEATING, id="heat_zones"
+        ),
+        pytest.param({"OperationMode": "Cool"}, HVACAction.COOLING, id="cool"),
+        pytest.param({"OperationMode": "Unknown"}, None, id="unknown"),
+        pytest.param(
+            {"OperationMode": "Heat", "Power": "False"}, HVACAction.OFF, id="off"
+        ),
+    ],
+)
+async def test_atw_zone_hvac_action(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_melcloud_client: AsyncMock,
+    overrides: dict[str, str],
+    expected_action: HVACAction | None,
+) -> None:
+    """Test the ATW zone HVAC action follows the unit's operation mode."""
+    context: dict[str, Any] = await async_load_json_object_fixture(
+        hass, "context.json", DOMAIN
+    )
+    settings = {
+        setting["name"]: setting
+        for setting in context["buildings"][0]["airToWaterUnits"][0]["settings"]
+    }
+    for name, value in overrides.items():
+        settings[name]["value"] = value
+    mock_melcloud_client.get_context.return_value = UserContext.model_validate(context)
+
+    await setup_integration(hass, mock_config_entry)
+
+    assert (state := hass.states.get(ATW_ZONE1_ENTITY_ID))
+    assert state.attributes.get(ATTR_HVAC_ACTION) == expected_action
+
+
 @pytest.mark.parametrize(
     ("entity_id", "method", "service", "service_data"),
     [