diff --git a/homeassistant/components/overkiz/sensor.py b/homeassistant/components/overkiz/sensor.py
index 5c54a1bd383c65..184b4938fefaf5 100644
--- a/homeassistant/components/overkiz/sensor.py
+++ b/homeassistant/components/overkiz/sensor.py
@@ -423,7 +423,7 @@ class OverkizSensorDescription(SensorEntityDescription):
     OverkizSensorDescription(
         key=OverkizState.CORE_REMAINING_HOT_WATER,
         name="Warm water remaining",
-        device_class=SensorDeviceClass.VOLUME,
+        device_class=SensorDeviceClass.VOLUME_STORAGE,
         state_class=SensorStateClass.MEASUREMENT,
         native_unit_of_measurement=UnitOfVolume.LITERS,
     ),