diff --git a/homeassistant/components/alarm_control_panel/__init__.py b/homeassistant/components/alarm_control_panel/__init__.py
index 8f523d5af7c..f210af3d670 100644
--- a/homeassistant/components/alarm_control_panel/__init__.py
+++ b/homeassistant/components/alarm_control_panel/__init__.py
@@ -133,7 +133,7 @@ class AlarmControlPanelEntity(Entity):
     _attr_changed_by: str | None = None
     _attr_code_arm_required: bool = True
     _attr_code_format: CodeFormat | None = None
-    _attr_supported_features: AlarmControlPanelEntityFeature | int
+    _attr_supported_features: AlarmControlPanelEntityFeature | int = 0
 
     @property
     def code_format(self) -> CodeFormat | None:
diff --git a/homeassistant/components/climate/__init__.py b/homeassistant/components/climate/__init__.py
index d19637a9be0..1cea229a306 100644
--- a/homeassistant/components/climate/__init__.py
+++ b/homeassistant/components/climate/__init__.py
@@ -225,7 +225,7 @@ class ClimateEntity(Entity):
     _attr_precision: float
     _attr_preset_mode: str | None
     _attr_preset_modes: list[str] | None
-    _attr_supported_features: ClimateEntityFeature | int
+    _attr_supported_features: ClimateEntityFeature | int = 0
     _attr_swing_mode: str | None
     _attr_swing_modes: list[str] | None
     _attr_target_humidity: int | None = None
diff --git a/homeassistant/components/fibaro/climate.py b/homeassistant/components/fibaro/climate.py
index 90a13fe8988..be2b8c6a527 100644
--- a/homeassistant/components/fibaro/climate.py
+++ b/homeassistant/components/fibaro/climate.py
@@ -126,7 +126,6 @@ class FibaroThermostat(FibaroDevice, ClimateEntity):
         self._target_temp_device: FibaroDevice | None = None
         self._op_mode_device: FibaroDevice | None = None
         self._fan_mode_device: FibaroDevice | None = None
-        self._attr_supported_features = 0
         self.entity_id = ENTITY_ID_FORMAT.format(self.ha_id)
 
         siblings = fibaro_device.fibaro_controller.get_siblings(fibaro_device)
diff --git a/homeassistant/components/intesishome/climate.py b/homeassistant/components/intesishome/climate.py
index 29cb30b81a2..bfdf406ee1a 100644
--- a/homeassistant/components/intesishome/climate.py
+++ b/homeassistant/components/intesishome/climate.py
@@ -172,7 +172,6 @@ class IntesisAC(ClimateEntity):
         self._hvane = None
         self._power = False
         self._fan_speed = None
-        self._attr_supported_features = 0
         self._power_consumption_heat = None
         self._power_consumption_cool = None
 
diff --git a/homeassistant/components/izone/climate.py b/homeassistant/components/izone/climate.py
index d65ebae24d4..a8dc90ad88c 100644
--- a/homeassistant/components/izone/climate.py
+++ b/homeassistant/components/izone/climate.py
@@ -445,7 +445,6 @@ class ZoneDevice(ClimateEntity):
         self._zone = zone
         self._name = zone.name.title()
 
-        self._attr_supported_features = 0
         if zone.type != Zone.Type.AUTO:
             self._state_to_pizone = {
                 HVACMode.OFF: Zone.Mode.CLOSE,
diff --git a/homeassistant/components/risco/alarm_control_panel.py b/homeassistant/components/risco/alarm_control_panel.py
index 7f4241048d7..116e022d216 100644
--- a/homeassistant/components/risco/alarm_control_panel.py
+++ b/homeassistant/components/risco/alarm_control_panel.py
@@ -107,7 +107,6 @@ class RiscoAlarm(AlarmControlPanelEntity):
         self._code_disarm_required = options[CONF_CODE_DISARM_REQUIRED]
         self._risco_to_ha = options[CONF_RISCO_STATES_TO_HA]
         self._ha_to_risco = options[CONF_HA_STATES_TO_RISCO]
-        self._attr_supported_features = 0
         self._attr_has_entity_name = True
         self._attr_name = None
         for state in self._ha_to_risco:
diff --git a/homeassistant/components/sia/alarm_control_panel.py b/homeassistant/components/sia/alarm_control_panel.py
index 0a2a17db200..25d3f447a09 100644
--- a/homeassistant/components/sia/alarm_control_panel.py
+++ b/homeassistant/components/sia/alarm_control_panel.py
@@ -90,7 +90,6 @@ class SIAAlarmControlPanel(SIABaseEntity, AlarmControlPanelEntity):
     """Class for SIA Alarm Control Panels."""
 
     entity_description: SIAAlarmControlPanelEntityDescription
-    _attr_supported_features = 0
 
     def __init__(
         self,
diff --git a/homeassistant/components/switcher_kis/climate.py b/homeassistant/components/switcher_kis/climate.py
index 99b9208e4ad..8462c8f02f8 100644
--- a/homeassistant/components/switcher_kis/climate.py
+++ b/homeassistant/components/switcher_kis/climate.py
@@ -104,7 +104,6 @@ class SwitcherClimateEntity(
         self._attr_target_temperature_step = 1
         self._attr_temperature_unit = TEMP_CELSIUS
 
-        self._attr_supported_features = 0
         self._attr_hvac_modes = [HVACMode.OFF]
         for mode in remote.modes_features:
             self._attr_hvac_modes.append(DEVICE_MODE_TO_HA[mode])
diff --git a/homeassistant/components/tuya/alarm_control_panel.py b/homeassistant/components/tuya/alarm_control_panel.py
index aae50902d03..d5122862e2c 100644
--- a/homeassistant/components/tuya/alarm_control_panel.py
+++ b/homeassistant/components/tuya/alarm_control_panel.py
@@ -97,7 +97,6 @@ class TuyaAlarmEntity(TuyaEntity, AlarmControlPanelEntity):
         description: AlarmControlPanelEntityDescription,
     ) -> None:
         """Init Tuya Alarm."""
-        self._attr_supported_features = 0
         super().__init__(device, device_manager)
         self.entity_description = description
         self._attr_unique_id = f"{super().unique_id}{description.key}"
diff --git a/homeassistant/components/tuya/climate.py b/homeassistant/components/tuya/climate.py
index 757701d5382..1b393dd5872 100644
--- a/homeassistant/components/tuya/climate.py
+++ b/homeassistant/components/tuya/climate.py
@@ -134,7 +134,6 @@ class TuyaClimateEntity(TuyaEntity, ClimateEntity):
     ) -> None:
         """Determine which values to use."""
         self._attr_target_temperature_step = 1.0
-        self._attr_supported_features = 0
         self.entity_description = description
 
         super().__init__(device, device_manager)
diff --git a/homeassistant/components/zwave_js/climate.py b/homeassistant/components/zwave_js/climate.py
index 06f2d225742..03f7fa94642 100644
--- a/homeassistant/components/zwave_js/climate.py
+++ b/homeassistant/components/zwave_js/climate.py
@@ -182,7 +182,6 @@ class ZWaveClimate(ZWaveBaseEntity, ClimateEntity):
             check_all_endpoints=True,
         )
         self._set_modes_and_presets()
-        self._attr_supported_features = 0
         if self._current_mode and len(self._hvac_presets) > 1:
             self._attr_supported_features |= ClimateEntityFeature.PRESET_MODE
         # If any setpoint value exists, we can assume temperature