diff --git a/homeassistant/components/generic_thermostat/climate.py b/homeassistant/components/generic_thermostat/climate.py
index 081bf1900d6..9e6df475d39 100644
--- a/homeassistant/components/generic_thermostat/climate.py
+++ b/homeassistant/components/generic_thermostat/climate.py
@@ -7,26 +7,18 @@ import math
 
 import voluptuous as vol
 
-from homeassistant.components.climate import (
-    PLATFORM_SCHEMA,
-    ClimateEntity,
-    ClimateEntityFeature,
-)
+from homeassistant.components.climate import PLATFORM_SCHEMA, ClimateEntity
 from homeassistant.components.climate.const import (
     ATTR_PRESET_MODE,
-    CURRENT_HVAC_COOL,
-    CURRENT_HVAC_HEAT,
-    CURRENT_HVAC_IDLE,
-    CURRENT_HVAC_OFF,
-    HVAC_MODE_COOL,
-    HVAC_MODE_HEAT,
-    HVAC_MODE_OFF,
     PRESET_ACTIVITY,
     PRESET_AWAY,
     PRESET_COMFORT,
     PRESET_HOME,
     PRESET_NONE,
     PRESET_SLEEP,
+    ClimateEntityFeature,
+    HVACAction,
+    HVACMode,
 )
 from homeassistant.const import (
     ATTR_ENTITY_ID,
@@ -102,7 +94,7 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
         vol.Optional(CONF_TARGET_TEMP): vol.Coerce(float),
         vol.Optional(CONF_KEEP_ALIVE): cv.positive_time_period,
         vol.Optional(CONF_INITIAL_HVAC_MODE): vol.In(
-            [HVAC_MODE_COOL, HVAC_MODE_HEAT, HVAC_MODE_OFF]
+            [HVACMode.COOL, HVACMode.HEAT, HVACMode.OFF]
         ),
         vol.Optional(CONF_PRECISION): vol.In(
             [PRECISION_TENTHS, PRECISION_HALVES, PRECISION_WHOLE]
@@ -207,9 +199,9 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
         self._temp_precision = precision
         self._temp_target_temperature_step = target_temperature_step
         if self.ac_mode:
-            self._hvac_list = [HVAC_MODE_COOL, HVAC_MODE_OFF]
+            self._hvac_list = [HVACMode.COOL, HVACMode.OFF]
         else:
-            self._hvac_list = [HVAC_MODE_HEAT, HVAC_MODE_OFF]
+            self._hvac_list = [HVACMode.HEAT, HVACMode.OFF]
         self._active = False
         self._cur_temp = None
         self._temp_lock = asyncio.Lock()
@@ -306,7 +298,7 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
 
         # Set default state to off
         if not self._hvac_mode:
-            self._hvac_mode = HVAC_MODE_OFF
+            self._hvac_mode = HVACMode.OFF
 
     @property
     def should_poll(self):
@@ -359,13 +351,13 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
 
         Need to be one of CURRENT_HVAC_*.
         """
-        if self._hvac_mode == HVAC_MODE_OFF:
-            return CURRENT_HVAC_OFF
+        if self._hvac_mode == HVACMode.OFF:
+            return HVACAction.OFF
         if not self._is_device_active:
-            return CURRENT_HVAC_IDLE
+            return HVACAction.IDLE
         if self.ac_mode:
-            return CURRENT_HVAC_COOL
-        return CURRENT_HVAC_HEAT
+            return HVACAction.COOLING
+        return HVACAction.HEATING
 
     @property
     def target_temperature(self):
@@ -379,14 +371,14 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
 
     async def async_set_hvac_mode(self, hvac_mode):
         """Set hvac mode."""
-        if hvac_mode == HVAC_MODE_HEAT:
-            self._hvac_mode = HVAC_MODE_HEAT
+        if hvac_mode == HVACMode.HEAT:
+            self._hvac_mode = HVACMode.HEAT
             await self._async_control_heating(force=True)
-        elif hvac_mode == HVAC_MODE_COOL:
-            self._hvac_mode = HVAC_MODE_COOL
+        elif hvac_mode == HVACMode.COOL:
+            self._hvac_mode = HVACMode.COOL
             await self._async_control_heating(force=True)
-        elif hvac_mode == HVAC_MODE_OFF:
-            self._hvac_mode = HVAC_MODE_OFF
+        elif hvac_mode == HVACMode.OFF:
+            self._hvac_mode = HVACMode.OFF
             if self._is_device_active:
                 await self._async_heater_turn_off()
         else:
@@ -432,8 +424,8 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
         self.async_write_ha_state()
 
     async def _check_switch_initial_state(self):
-        """Prevent the device from keep running if HVAC_MODE_OFF."""
-        if self._hvac_mode == HVAC_MODE_OFF and self._is_device_active:
+        """Prevent the device from keep running if HVACMode.OFF."""
+        if self._hvac_mode == HVACMode.OFF and self._is_device_active:
             _LOGGER.warning(
                 "The climate mode is OFF, but the switch device is ON. Turning off device %s",
                 self.heater_entity_id,
@@ -477,7 +469,7 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
                     self._target_temp,
                 )
 
-            if not self._active or self._hvac_mode == HVAC_MODE_OFF:
+            if not self._active or self._hvac_mode == HVACMode.OFF:
                 return
 
             # If the `force` argument is True, we
@@ -488,7 +480,7 @@ class GenericThermostat(ClimateEntity, RestoreEntity):
                 if self._is_device_active:
                     current_state = STATE_ON
                 else:
-                    current_state = HVAC_MODE_OFF
+                    current_state = HVACMode.OFF
                 try:
                     long_enough = condition.state(
                         self.hass,
diff --git a/tests/components/generic_thermostat/test_climate.py b/tests/components/generic_thermostat/test_climate.py
index 70337f6f679..d607c6dbb61 100644
--- a/tests/components/generic_thermostat/test_climate.py
+++ b/tests/components/generic_thermostat/test_climate.py
@@ -10,15 +10,13 @@ from homeassistant.components import input_boolean, switch
 from homeassistant.components.climate.const import (
     ATTR_PRESET_MODE,
     DOMAIN,
-    HVAC_MODE_COOL,
-    HVAC_MODE_HEAT,
-    HVAC_MODE_OFF,
     PRESET_ACTIVITY,
     PRESET_AWAY,
     PRESET_COMFORT,
     PRESET_HOME,
     PRESET_NONE,
     PRESET_SLEEP,
+    HVACMode,
 )
 from homeassistant.components.generic_thermostat import (
     DOMAIN as GENERIC_THERMOSTAT_DOMAIN,
@@ -115,7 +113,7 @@ async def test_heater_input_boolean(hass, setup_comp_1):
                 "name": "test",
                 "heater": heater_switch,
                 "target_sensor": ENT_SENSOR,
-                "initial_hvac_mode": HVAC_MODE_HEAT,
+                "initial_hvac_mode": HVACMode.HEAT,
             }
         },
     )
@@ -150,7 +148,7 @@ async def test_heater_switch(hass, setup_comp_1, enable_custom_integrations):
                 "name": "test",
                 "heater": heater_switch,
                 "target_sensor": ENT_SENSOR,
-                "initial_hvac_mode": HVAC_MODE_HEAT,
+                "initial_hvac_mode": HVACMode.HEAT,
             }
         },
     )
@@ -217,7 +215,7 @@ async def setup_comp_2(hass):
                 "home_temp": 19,
                 "comfort_temp": 20,
                 "activity_temp": 21,
-                "initial_hvac_mode": HVAC_MODE_HEAT,
+                "initial_hvac_mode": HVACMode.HEAT,
             }
         },
     )
@@ -243,7 +241,7 @@ async def test_setup_defaults_to_unknown(hass):
         },
     )
     await hass.async_block_till_done()
-    assert hass.states.get(ENTITY).state == HVAC_MODE_OFF
+    assert hass.states.get(ENTITY).state == HVACMode.OFF
 
 
 async def test_setup_gets_current_temp_from_sensor(hass):
@@ -283,7 +281,7 @@ async def test_get_hvac_modes(hass, setup_comp_2):
     """Test that the operation list returns the correct modes."""
     state = hass.states.get(ENTITY)
     modes = state.attributes.get("hvac_modes")
-    assert modes == [HVAC_MODE_HEAT, HVAC_MODE_OFF]
+    assert modes == [HVACMode.HEAT, HVACMode.OFF]
 
 
 async def test_set_target_temp(hass, setup_comp_2):
@@ -519,7 +517,7 @@ async def test_running_when_hvac_mode_is_off(hass, setup_comp_2):
     """Test that the switch turns off when enabled is set False."""
     calls = _setup_switch(hass, True)
     await common.async_set_temperature(hass, 30)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == HASS_DOMAIN
@@ -531,7 +529,7 @@ async def test_no_state_change_when_hvac_mode_off(hass, setup_comp_2):
     """Test that the switch doesn't turn on when enabled is False."""
     calls = _setup_switch(hass, False)
     await common.async_set_temperature(hass, 30)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     _setup_sensor(hass, 25)
     await hass.async_block_till_done()
     assert len(calls) == 0
@@ -542,12 +540,12 @@ async def test_hvac_mode_heat(hass, setup_comp_2):
 
     Switch turns on when temp below setpoint and mode changes.
     """
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     await common.async_set_temperature(hass, 30)
     _setup_sensor(hass, 25)
     await hass.async_block_till_done()
     calls = _setup_switch(hass, False)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_HEAT)
+    await common.async_set_hvac_mode(hass, HVACMode.HEAT)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == HASS_DOMAIN
@@ -588,7 +586,7 @@ async def setup_comp_3(hass):
                 "heater": ENT_SWITCH,
                 "target_sensor": ENT_SENSOR,
                 "ac_mode": True,
-                "initial_hvac_mode": HVAC_MODE_COOL,
+                "initial_hvac_mode": HVACMode.COOL,
             }
         },
     )
@@ -624,12 +622,12 @@ async def test_hvac_mode_cool(hass, setup_comp_3):
 
     Switch turns on when temp below setpoint and mode changes.
     """
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     await common.async_set_temperature(hass, 25)
     _setup_sensor(hass, 30)
     await hass.async_block_till_done()
     calls = _setup_switch(hass, False)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_COOL)
+    await common.async_set_hvac_mode(hass, HVACMode.COOL)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == HASS_DOMAIN
@@ -698,7 +696,7 @@ async def test_running_when_operating_mode_is_off_2(hass, setup_comp_3):
     """Test that the switch turns off when enabled is set False."""
     calls = _setup_switch(hass, True)
     await common.async_set_temperature(hass, 30)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == HASS_DOMAIN
@@ -710,7 +708,7 @@ async def test_no_state_change_when_operation_mode_off_2(hass, setup_comp_3):
     """Test that the switch doesn't turn on when enabled is False."""
     calls = _setup_switch(hass, False)
     await common.async_set_temperature(hass, 30)
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     _setup_sensor(hass, 35)
     await hass.async_block_till_done()
     assert len(calls) == 0
@@ -733,7 +731,7 @@ async def setup_comp_4(hass):
                 "target_sensor": ENT_SENSOR,
                 "ac_mode": True,
                 "min_cycle_duration": datetime.timedelta(minutes=10),
-                "initial_hvac_mode": HVAC_MODE_COOL,
+                "initial_hvac_mode": HVACMode.COOL,
             }
         },
     )
@@ -799,7 +797,7 @@ async def test_mode_change_ac_trigger_off_not_long_enough(hass, setup_comp_4):
     _setup_sensor(hass, 25)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -814,7 +812,7 @@ async def test_mode_change_ac_trigger_on_not_long_enough(hass, setup_comp_4):
     _setup_sensor(hass, 30)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_HEAT)
+    await common.async_set_hvac_mode(hass, HVACMode.HEAT)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -839,7 +837,7 @@ async def setup_comp_5(hass):
                 "target_sensor": ENT_SENSOR,
                 "ac_mode": True,
                 "min_cycle_duration": datetime.timedelta(minutes=10),
-                "initial_hvac_mode": HVAC_MODE_COOL,
+                "initial_hvac_mode": HVACMode.COOL,
             }
         },
     )
@@ -905,7 +903,7 @@ async def test_mode_change_ac_trigger_off_not_long_enough_2(hass, setup_comp_5):
     _setup_sensor(hass, 25)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -920,7 +918,7 @@ async def test_mode_change_ac_trigger_on_not_long_enough_2(hass, setup_comp_5):
     _setup_sensor(hass, 30)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_HEAT)
+    await common.async_set_hvac_mode(hass, HVACMode.HEAT)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -944,7 +942,7 @@ async def setup_comp_6(hass):
                 "heater": ENT_SWITCH,
                 "target_sensor": ENT_SENSOR,
                 "min_cycle_duration": datetime.timedelta(minutes=10),
-                "initial_hvac_mode": HVAC_MODE_HEAT,
+                "initial_hvac_mode": HVACMode.HEAT,
             }
         },
     )
@@ -1010,7 +1008,7 @@ async def test_mode_change_heater_trigger_off_not_long_enough(hass, setup_comp_6
     _setup_sensor(hass, 30)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_OFF)
+    await common.async_set_hvac_mode(hass, HVACMode.OFF)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -1025,7 +1023,7 @@ async def test_mode_change_heater_trigger_on_not_long_enough(hass, setup_comp_6)
     _setup_sensor(hass, 25)
     await hass.async_block_till_done()
     assert len(calls) == 0
-    await common.async_set_hvac_mode(hass, HVAC_MODE_HEAT)
+    await common.async_set_hvac_mode(hass, HVACMode.HEAT)
     assert len(calls) == 1
     call = calls[0]
     assert call.domain == "homeassistant"
@@ -1052,7 +1050,7 @@ async def setup_comp_7(hass):
                 "ac_mode": True,
                 "min_cycle_duration": datetime.timedelta(minutes=15),
                 "keep_alive": datetime.timedelta(minutes=10),
-                "initial_hvac_mode": HVAC_MODE_COOL,
+                "initial_hvac_mode": HVACMode.COOL,
             }
         },
     )
@@ -1124,7 +1122,7 @@ async def setup_comp_8(hass):
                 "target_sensor": ENT_SENSOR,
                 "min_cycle_duration": datetime.timedelta(minutes=15),
                 "keep_alive": datetime.timedelta(minutes=10),
-                "initial_hvac_mode": HVAC_MODE_HEAT,
+                "initial_hvac_mode": HVACMode.HEAT,
             }
         },
     )
@@ -1238,7 +1236,7 @@ async def test_custom_setup_params(hass):
     assert state.attributes.get("target_temp_step") == TARGET_TEMP_STEP
 
 
-@pytest.mark.parametrize("hvac_mode", [HVAC_MODE_OFF, HVAC_MODE_HEAT, HVAC_MODE_COOL])
+@pytest.mark.parametrize("hvac_mode", [HVACMode.OFF, HVACMode.HEAT, HVACMode.COOL])
 async def test_restore_state(hass, hvac_mode):
     """Ensure states are restored on startup."""
     mock_restore_cache(
@@ -1284,7 +1282,7 @@ async def test_no_restore_state(hass):
         (
             State(
                 "climate.test_thermostat",
-                HVAC_MODE_OFF,
+                HVACMode.OFF,
                 {ATTR_TEMPERATURE: "20", ATTR_PRESET_MODE: PRESET_AWAY},
             ),
         ),
@@ -1308,7 +1306,7 @@ async def test_no_restore_state(hass):
     await hass.async_block_till_done()
     state = hass.states.get("climate.test_thermostat")
     assert state.attributes[ATTR_TEMPERATURE] == 22
-    assert state.state == HVAC_MODE_OFF
+    assert state.state == HVACMode.OFF
 
 
 async def test_initial_hvac_off_force_heater_off(hass):
@@ -1333,14 +1331,14 @@ async def test_initial_hvac_off_force_heater_off(hass):
                 "heater": ENT_SWITCH,
                 "target_sensor": ENT_SENSOR,
                 "target_temp": 20,
-                "initial_hvac_mode": HVAC_MODE_OFF,
+                "initial_hvac_mode": HVACMode.OFF,
             }
         },
     )
     await hass.async_block_till_done()
     state = hass.states.get("climate.test_thermostat")
     # 'initial_hvac_mode' will force state but must prevent heather keep working
-    assert state.state == HVAC_MODE_OFF
+    assert state.state == HVACMode.OFF
     # heater must be switched off
     assert len(calls) == 1
     call = calls[0]
@@ -1360,7 +1358,7 @@ async def test_restore_will_turn_off_(hass):
         (
             State(
                 "climate.test_thermostat",
-                HVAC_MODE_HEAT,
+                HVACMode.HEAT,
                 {ATTR_TEMPERATURE: "18", ATTR_PRESET_MODE: PRESET_NONE},
             ),
             State(heater_switch, STATE_ON, {}),
@@ -1393,7 +1391,7 @@ async def test_restore_will_turn_off_(hass):
     await hass.async_block_till_done()
     state = hass.states.get("climate.test_thermostat")
     assert state.attributes[ATTR_TEMPERATURE] == 20
-    assert state.state == HVAC_MODE_HEAT
+    assert state.state == HVACMode.HEAT
     assert hass.states.get(heater_switch).state == STATE_ON
 
 
@@ -1408,7 +1406,7 @@ async def test_restore_will_turn_off_when_loaded_second(hass):
         (
             State(
                 "climate.test_thermostat",
-                HVAC_MODE_HEAT,
+                HVACMode.HEAT,
                 {ATTR_TEMPERATURE: "18", ATTR_PRESET_MODE: PRESET_NONE},
             ),
             State(heater_switch, STATE_ON, {}),
@@ -1432,14 +1430,14 @@ async def test_restore_will_turn_off_when_loaded_second(hass):
                 "heater": heater_switch,
                 "target_sensor": ENT_SENSOR,
                 "target_temp": 20,
-                "initial_hvac_mode": HVAC_MODE_OFF,
+                "initial_hvac_mode": HVACMode.OFF,
             }
         },
     )
     await hass.async_block_till_done()
     state = hass.states.get("climate.test_thermostat")
     assert state.attributes[ATTR_TEMPERATURE] == 20
-    assert state.state == HVAC_MODE_OFF
+    assert state.state == HVACMode.OFF
 
     calls_on = async_mock_service(hass, ha.DOMAIN, SERVICE_TURN_ON)
     calls_off = async_mock_service(hass, ha.DOMAIN, SERVICE_TURN_OFF)
@@ -1473,13 +1471,13 @@ async def test_restore_state_uncoherence_case(hass):
 
     state = hass.states.get(ENTITY)
     assert state.attributes[ATTR_TEMPERATURE] == 20
-    assert state.state == HVAC_MODE_OFF
+    assert state.state == HVACMode.OFF
     assert len(calls) == 0
 
     calls = _setup_switch(hass, False)
     await hass.async_block_till_done()
     state = hass.states.get(ENTITY)
-    assert state.state == HVAC_MODE_OFF
+    assert state.state == HVACMode.OFF
 
 
 async def _setup_climate(hass):
@@ -1501,7 +1499,7 @@ async def _setup_climate(hass):
     )
 
 
-def _mock_restore_cache(hass, temperature=20, hvac_mode=HVAC_MODE_OFF):
+def _mock_restore_cache(hass, temperature=20, hvac_mode=HVACMode.OFF):
     mock_restore_cache(
         hass,
         (