Use temperature of current preset when set fritz HVAC mode to HEAT

If the HVAC mode of the Fritzbox thermostats changes from `HVACMode.OFF`
to `HVAMode.HEAT`, the current preset (COMFORT / ECO) should be
observed. Depending on the status of the current preset, the set
temperature of comfort / eco is set as the new temperature.

homeassistant/components/fritzbox/climate.py

@@ -33,6 +33,7 @@
 )
 from .coordinator import FritzboxConfigEntry, FritzboxDataUpdateCoordinator
 from .model import ClimateExtraAttributes
+from .sensor import value_scheduled_preset
 
 HVAC_MODES = [HVACMode.HEAT, HVACMode.OFF]
 PRESET_HOLIDAY = "holiday"
@@ -174,6 +175,8 @@ async def async_set_hvac_mode(self, hvac_mode: HVACMode) -> None:
             return
         if hvac_mode == HVACMode.OFF:
             await self.async_set_temperature(temperature=OFF_REPORT_SET_TEMPERATURE)
+        elif value_scheduled_preset(self.data) is PRESET_ECO:
+            await self.async_set_temperature(temperature=self.data.eco_temperature)
         else:
             await self.async_set_temperature(temperature=self.data.comfort_temperature)
 

tests/components/fritzbox/test_climate.py

@@ -376,6 +376,27 @@ async def test_set_hvac_mode_heat(hass: HomeAssistant, fritz: Mock) -> None:
     assert device.set_target_temperature.call_args_list == [call(22)]
 
 
+async def test_set_hvac_mode_heat_eco(hass: HomeAssistant, fritz: Mock) -> None:
+    """Test setting hvac mode with current scheduled eco preset."""
+    device = FritzDeviceClimateMock()
+    device.target_temperature = 0.0
+
+    # Prepare scheduled_preset to PRESET_ECO
+    device.nextchange_temperature = device.comfort_temperature
+
+    assert await setup_config_entry(
+        hass, MOCK_CONFIG[FB_DOMAIN][CONF_DEVICES][0], ENTITY_ID, device, fritz
+    )
+
+    await hass.services.async_call(
+        CLIMATE_DOMAIN,
+        SERVICE_SET_HVAC_MODE,
+        {ATTR_ENTITY_ID: ENTITY_ID, ATTR_HVAC_MODE: HVACMode.HEAT},
+        True,
+    )
+    assert device.set_target_temperature.call_args_list == [call(16)]
+
+
 async def test_set_preset_mode_comfort(hass: HomeAssistant, fritz: Mock) -> None:
     """Test setting preset mode."""
     device = FritzDeviceClimateMock()