diff --git a/custom_components/luxtronik/sensor.py b/custom_components/luxtronik/sensor.py
index ab7b8da..335136c 100644
--- a/custom_components/luxtronik/sensor.py
+++ b/custom_components/luxtronik/sensor.py
@@ -459,7 +459,7 @@ def _restore_attr_value(self, value: Any | None) -> Any:
                     if day == name: 
                         vals.append(idx)
                         break
-            if len(vals):
+            if vals:
                 return vals 
         return time.min 
 
diff --git a/custom_components/luxtronik/sensor_entities_predefined.py b/custom_components/luxtronik/sensor_entities_predefined.py
index a00300e..9b61067 100644
--- a/custom_components/luxtronik/sensor_entities_predefined.py
+++ b/custom_components/luxtronik/sensor_entities_predefined.py
@@ -468,6 +468,7 @@
         native_unit_of_measurement=UnitOfPower.WATT,
         entity_registry_enabled_default=False,
         native_precision=0,
+        min_firmware_version_minor=FirmwareVersionMinor.minor_88,
     ),
     # endregion Main heatpump
     # region Heating