diff --git a/homeassistant/components/overkiz/climate_entities/atlantic_electrical_heater_with_adjustable_temperature_setpoint.py b/homeassistant/components/overkiz/climate_entities/atlantic_electrical_heater_with_adjustable_temperature_setpoint.py
index 47dc75710ec..64a7dc1e645 100644
--- a/homeassistant/components/overkiz/climate_entities/atlantic_electrical_heater_with_adjustable_temperature_setpoint.py
+++ b/homeassistant/components/overkiz/climate_entities/atlantic_electrical_heater_with_adjustable_temperature_setpoint.py
@@ -143,7 +143,9 @@ class AtlanticElectricalHeaterWithAdjustableTemperatureSetpoint(
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return temperature.value_as_float
         return None
 
diff --git a/homeassistant/components/overkiz/climate_entities/atlantic_electrical_towel_dryer.py b/homeassistant/components/overkiz/climate_entities/atlantic_electrical_towel_dryer.py
index 16568c0b1b7..e49fc4358e9 100644
--- a/homeassistant/components/overkiz/climate_entities/atlantic_electrical_towel_dryer.py
+++ b/homeassistant/components/overkiz/climate_entities/atlantic_electrical_towel_dryer.py
@@ -95,7 +95,9 @@ class AtlanticElectricalTowelDryer(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return cast(float, temperature.value)
 
         return None
diff --git a/homeassistant/components/overkiz/climate_entities/atlantic_heat_recovery_ventilation.py b/homeassistant/components/overkiz/climate_entities/atlantic_heat_recovery_ventilation.py
index 698979672ea..f1d96b5687b 100644
--- a/homeassistant/components/overkiz/climate_entities/atlantic_heat_recovery_ventilation.py
+++ b/homeassistant/components/overkiz/climate_entities/atlantic_heat_recovery_ventilation.py
@@ -69,7 +69,9 @@ class AtlanticHeatRecoveryVentilation(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return cast(float, temperature.value)
 
         return None
diff --git a/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_heating_zone.py b/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_heating_zone.py
index 72a9182974f..bf6aa43644e 100644
--- a/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_heating_zone.py
+++ b/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_heating_zone.py
@@ -108,7 +108,9 @@ class AtlanticPassAPCHeatingZone(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return cast(float, temperature.value)
 
         return None
diff --git a/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_zone_control_zone.py b/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_zone_control_zone.py
index c61c92a3c44..261acc2838c 100644
--- a/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_zone_control_zone.py
+++ b/homeassistant/components/overkiz/climate_entities/atlantic_pass_apc_zone_control_zone.py
@@ -24,7 +24,7 @@ OVERKIZ_MODE_TO_PRESET_MODES: dict[str, str] = {
 
 PRESET_MODES_TO_OVERKIZ = {v: k for k, v in OVERKIZ_MODE_TO_PRESET_MODES.items()}
 
-TEMPERATURE_ZONECONTROL_DEVICE_INDEX = 1
+TEMPERATURE_ZONECONTROL_DEVICE_INDEX = 20
 
 
 # Those device depends on a main probe that choose the operating mode (heating, cooling, ...)
@@ -65,10 +65,15 @@ class AtlanticPassAPCZoneControlZone(AtlanticPassAPCHeatingZone):
         """Return hvac operation ie. heat, cool, dry, off mode."""
 
         if (
-            state := self.zone_control_device.states[
-                OverkizState.IO_PASS_APC_OPERATING_MODE
-            ]
-        ) is not None and (value := state.value_as_str) is not None:
+            self.zone_control_device is not None
+            and (
+                state := self.zone_control_device.states[
+                    OverkizState.IO_PASS_APC_OPERATING_MODE
+                ]
+            )
+            is not None
+            and (value := state.value_as_str) is not None
+        ):
             return OVERKIZ_TO_HVAC_MODE[value]
         return HVACMode.OFF
 
diff --git a/homeassistant/components/overkiz/climate_entities/somfy_heating_temperature_interface.py b/homeassistant/components/overkiz/climate_entities/somfy_heating_temperature_interface.py
index becb807d41a..85ce7ae57e3 100644
--- a/homeassistant/components/overkiz/climate_entities/somfy_heating_temperature_interface.py
+++ b/homeassistant/components/overkiz/climate_entities/somfy_heating_temperature_interface.py
@@ -166,7 +166,9 @@ class SomfyHeatingTemperatureInterface(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return temperature.value_as_float
         return None
 
diff --git a/homeassistant/components/overkiz/climate_entities/somfy_thermostat.py b/homeassistant/components/overkiz/climate_entities/somfy_thermostat.py
index 615c618dd40..829a3bad03b 100644
--- a/homeassistant/components/overkiz/climate_entities/somfy_thermostat.py
+++ b/homeassistant/components/overkiz/climate_entities/somfy_thermostat.py
@@ -104,7 +104,9 @@ class SomfyThermostat(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return cast(float, temperature.value)
         return None
 
diff --git a/homeassistant/components/overkiz/climate_entities/valve_heating_temperature_interface.py b/homeassistant/components/overkiz/climate_entities/valve_heating_temperature_interface.py
index 893e4ca3d8e..e2165e8b6c6 100644
--- a/homeassistant/components/overkiz/climate_entities/valve_heating_temperature_interface.py
+++ b/homeassistant/components/overkiz/climate_entities/valve_heating_temperature_interface.py
@@ -91,7 +91,9 @@ class ValveHeatingTemperatureInterface(OverkizEntity, ClimateEntity):
     @property
     def current_temperature(self) -> float | None:
         """Return the current temperature."""
-        if temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]:
+        if self.temperature_device is not None and (
+            temperature := self.temperature_device.states[OverkizState.CORE_TEMPERATURE]
+        ):
             return temperature.value_as_float
 
         return None
diff --git a/homeassistant/components/overkiz/executor.py b/homeassistant/components/overkiz/executor.py
index e11dc59cc27..94b2c1b25fa 100644
--- a/homeassistant/components/overkiz/executor.py
+++ b/homeassistant/components/overkiz/executor.py
@@ -41,9 +41,9 @@ class OverkizExecutor:
         """Return Overkiz device linked to this entity."""
         return self.coordinator.data[self.device_url]
 
-    def linked_device(self, index: int) -> Device:
+    def linked_device(self, index: int) -> Device | None:
         """Return Overkiz device sharing the same base url."""
-        return self.coordinator.data[f"{self.base_device_url}#{index}"]
+        return self.coordinator.data.get(f"{self.base_device_url}#{index}")
 
     def select_command(self, *commands: str) -> str | None:
         """Select first existing command in a list of commands."""