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 a3a2be171c7..3b02523ec20 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
@@ -24,6 +24,7 @@ PRESET_COMFORT1 = "comfort-1"
 PRESET_COMFORT2 = "comfort-2"
 PRESET_FROST_PROTECTION = "frost_protection"
 PRESET_PROG = "prog"
+PRESET_EXTERNAL = "external"
 
 
 # Map Overkiz presets to Home Assistant presets
@@ -36,6 +37,7 @@ OVERKIZ_TO_PRESET_MODE: dict[str, str] = {
     OverkizCommandParam.COMFORT_2: PRESET_COMFORT2,
     OverkizCommandParam.AUTO: PRESET_AUTO,
     OverkizCommandParam.BOOST: PRESET_BOOST,
+    OverkizCommandParam.EXTERNAL: PRESET_EXTERNAL,
     OverkizCommandParam.INTERNAL: PRESET_PROG,
 }
 
@@ -48,6 +50,7 @@ OVERKIZ_TO_HVAC_MODE: dict[str, str] = {
     OverkizCommandParam.AUTO: HVACMode.AUTO,
     OverkizCommandParam.BASIC: HVACMode.HEAT,
     OverkizCommandParam.STANDBY: HVACMode.OFF,
+    OverkizCommandParam.EXTERNAL: HVACMode.AUTO,
     OverkizCommandParam.INTERNAL: HVACMode.AUTO,
 }
 
@@ -96,15 +99,26 @@ class AtlanticElectricalHeaterWithAdjustableTemperatureSetpoint(
     @property
     def preset_mode(self) -> str | None:
         """Return the current preset mode, e.g., home, away, temp."""
+
+        states = self.device.states
+
         if (
-            state := self.device.states[OverkizState.IO_TARGET_HEATING_LEVEL]
+            operating_mode := states[OverkizState.CORE_OPERATING_MODE]
+        ) and operating_mode.value_as_str == OverkizCommandParam.EXTERNAL:
+            return PRESET_EXTERNAL
+
+        if (
+            state := states[OverkizState.IO_TARGET_HEATING_LEVEL]
         ) and state.value_as_str:
             return OVERKIZ_TO_PRESET_MODE[state.value_as_str]
         return None
 
     async def async_set_preset_mode(self, preset_mode: str) -> None:
         """Set new preset mode."""
-        if preset_mode in [PRESET_AUTO, PRESET_PROG]:
+
+        if preset_mode == PRESET_EXTERNAL:
+            command = OverkizCommand.SET_SCHEDULING_TYPE
+        elif preset_mode in [PRESET_AUTO, PRESET_PROG]:
             command = OverkizCommand.SET_OPERATING_MODE
         else:
             command = OverkizCommand.SET_HEATING_LEVEL
diff --git a/homeassistant/components/overkiz/manifest.json b/homeassistant/components/overkiz/manifest.json
index eb1eee8a7b5..c5d272b0489 100644
--- a/homeassistant/components/overkiz/manifest.json
+++ b/homeassistant/components/overkiz/manifest.json
@@ -4,7 +4,7 @@
   "config_flow": true,
   "integration_type": "hub",
   "documentation": "https://www.home-assistant.io/integrations/overkiz",
-  "requirements": ["pyoverkiz==1.7.2"],
+  "requirements": ["pyoverkiz==1.7.3"],
   "zeroconf": [
     {
       "type": "_kizbox._tcp.local.",
diff --git a/requirements_all.txt b/requirements_all.txt
index ddef4bc8ae2..aa4a77c72bf 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -1820,7 +1820,7 @@ pyotgw==2.1.3
 pyotp==2.8.0
 
 # homeassistant.components.overkiz
-pyoverkiz==1.7.2
+pyoverkiz==1.7.3
 
 # homeassistant.components.openweathermap
 pyowm==3.2.0
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index 33df1afdc77..7d04cef4976 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -1297,7 +1297,7 @@ pyotgw==2.1.3
 pyotp==2.8.0
 
 # homeassistant.components.overkiz
-pyoverkiz==1.7.2
+pyoverkiz==1.7.3
 
 # homeassistant.components.openweathermap
 pyowm==3.2.0