diff --git a/homeassistant/components/melcloud/climate.py b/homeassistant/components/melcloud/climate.py
index 4c085821ee7..b16221923de 100644
--- a/homeassistant/components/melcloud/climate.py
+++ b/homeassistant/components/melcloud/climate.py
@@ -14,17 +14,13 @@ from pymelcloud.atw_device import (
 )
 import voluptuous as vol
 
-from homeassistant.components.climate import ClimateEntity, ClimateEntityFeature
+from homeassistant.components.climate import ClimateEntity
 from homeassistant.components.climate.const import (
     ATTR_HVAC_MODE,
     DEFAULT_MAX_TEMP,
     DEFAULT_MIN_TEMP,
-    HVAC_MODE_COOL,
-    HVAC_MODE_DRY,
-    HVAC_MODE_FAN_ONLY,
-    HVAC_MODE_HEAT,
-    HVAC_MODE_HEAT_COOL,
-    HVAC_MODE_OFF,
+    ClimateEntityFeature,
+    HVACMode,
 )
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import ATTR_TEMPERATURE, TEMP_CELSIUS
@@ -49,18 +45,18 @@ SCAN_INTERVAL = timedelta(seconds=60)
 
 
 ATA_HVAC_MODE_LOOKUP = {
-    ata.OPERATION_MODE_HEAT: HVAC_MODE_HEAT,
-    ata.OPERATION_MODE_DRY: HVAC_MODE_DRY,
-    ata.OPERATION_MODE_COOL: HVAC_MODE_COOL,
-    ata.OPERATION_MODE_FAN_ONLY: HVAC_MODE_FAN_ONLY,
-    ata.OPERATION_MODE_HEAT_COOL: HVAC_MODE_HEAT_COOL,
+    ata.OPERATION_MODE_HEAT: HVACMode.HEAT,
+    ata.OPERATION_MODE_DRY: HVACMode.DRY,
+    ata.OPERATION_MODE_COOL: HVACMode.COOL,
+    ata.OPERATION_MODE_FAN_ONLY: HVACMode.FAN_ONLY,
+    ata.OPERATION_MODE_HEAT_COOL: HVACMode.HEAT_COOL,
 }
 ATA_HVAC_MODE_REVERSE_LOOKUP = {v: k for k, v in ATA_HVAC_MODE_LOOKUP.items()}
 
 
 ATW_ZONE_HVAC_MODE_LOOKUP = {
-    atw.ZONE_OPERATION_MODE_HEAT: HVAC_MODE_HEAT,
-    atw.ZONE_OPERATION_MODE_COOL: HVAC_MODE_COOL,
+    atw.ZONE_OPERATION_MODE_HEAT: HVACMode.HEAT,
+    atw.ZONE_OPERATION_MODE_COOL: HVACMode.COOL,
 }
 ATW_ZONE_HVAC_MODE_REVERSE_LOOKUP = {v: k for k, v in ATW_ZONE_HVAC_MODE_LOOKUP.items()}
 
@@ -161,16 +157,16 @@ class AtaDeviceClimate(MelCloudClimate):
         return attr
 
     @property
-    def hvac_mode(self) -> str:
+    def hvac_mode(self) -> HVACMode:
         """Return hvac operation ie. heat, cool mode."""
         mode = self._device.operation_mode
         if not self._device.power or mode is None:
-            return HVAC_MODE_OFF
+            return HVACMode.OFF
         return ATA_HVAC_MODE_LOOKUP.get(mode)
 
     def _apply_set_hvac_mode(self, hvac_mode: str, set_dict: dict[str, Any]) -> None:
         """Apply hvac mode changes to a dict used to call _device.set."""
-        if hvac_mode == HVAC_MODE_OFF:
+        if hvac_mode == HVACMode.OFF:
             set_dict["power"] = False
             return
 
@@ -179,19 +175,19 @@ class AtaDeviceClimate(MelCloudClimate):
             raise ValueError(f"Invalid hvac_mode [{hvac_mode}]")
 
         set_dict["operation_mode"] = operation_mode
-        if self.hvac_mode == HVAC_MODE_OFF:
+        if self.hvac_mode == HVACMode.OFF:
             set_dict["power"] = True
 
-    async def async_set_hvac_mode(self, hvac_mode: str) -> None:
+    async def async_set_hvac_mode(self, hvac_mode: HVACMode) -> None:
         """Set new target hvac mode."""
         set_dict = {}
         self._apply_set_hvac_mode(hvac_mode, set_dict)
         await self._device.set(set_dict)
 
     @property
-    def hvac_modes(self) -> list[str]:
+    def hvac_modes(self) -> list[HVACMode]:
         """Return the list of available hvac operation modes."""
-        return [HVAC_MODE_OFF] + [
+        return [HVACMode.OFF] + [
             ATA_HVAC_MODE_LOOKUP.get(mode) for mode in self._device.operation_modes
         ]
 
@@ -319,16 +315,16 @@ class AtwDeviceZoneClimate(MelCloudClimate):
         return data
 
     @property
-    def hvac_mode(self) -> str:
+    def hvac_mode(self) -> HVACMode:
         """Return hvac operation ie. heat, cool mode."""
         mode = self._zone.operation_mode
         if not self._device.power or mode is None:
-            return HVAC_MODE_OFF
-        return ATW_ZONE_HVAC_MODE_LOOKUP.get(mode, HVAC_MODE_OFF)
+            return HVACMode.OFF
+        return ATW_ZONE_HVAC_MODE_LOOKUP.get(mode, HVACMode.OFF)
 
-    async def async_set_hvac_mode(self, hvac_mode: str) -> None:
+    async def async_set_hvac_mode(self, hvac_mode: HVACMode) -> None:
         """Set new target hvac mode."""
-        if hvac_mode == HVAC_MODE_OFF:
+        if hvac_mode == HVACMode.OFF:
             await self._device.set({"power": False})
             return
 
@@ -340,12 +336,12 @@ class AtwDeviceZoneClimate(MelCloudClimate):
             props = {PROPERTY_ZONE_1_OPERATION_MODE: operation_mode}
         else:
             props = {PROPERTY_ZONE_2_OPERATION_MODE: operation_mode}
-        if self.hvac_mode == HVAC_MODE_OFF:
+        if self.hvac_mode == HVACMode.OFF:
             props["power"] = True
         await self._device.set(props)
 
     @property
-    def hvac_modes(self) -> list[str]:
+    def hvac_modes(self) -> list[HVACMode]:
         """Return the list of available hvac operation modes."""
         return [self.hvac_mode]