diff --git a/src/Sensors.h b/src/Sensors.h
index 53b9285..8095414 100644
--- a/src/Sensors.h
+++ b/src/Sensors.h
@@ -336,76 +336,61 @@ public:
     return updated;
   }
 
-  static float getMeanValueByPurpose(Purpose purpose, const ValueType valueType, const AverageType avgType = AverageType::MEAN, bool onlyConnected = true) {
+  static float getMeanValueByPurpose(Purpose purpose, const ValueType valueType, const AverageType avgType = AverageType::MEAN, const bool onlyConnected = true, const float defaultValue = NAN) {
     if (settings == nullptr || results == nullptr) {
-      return 0.0f;
+      return defaultValue;
     }
 
     uint8_t valueId = (uint8_t) valueType;
     if (!isValidValueId(valueId)) {
-      return 0.0f;
+      return defaultValue;
     }
     
-    if (avgType == AverageType::MEAN) {
-      float value = 0.0f;
-      uint8_t amount = 0;
+    float value = 0.0f;
+    uint8_t amount = 0;
 
+    if (avgType == AverageType::MEAN) {
+      float sum = 0.0f;
       for (uint8_t id = 0; id <= getMaxSensorId(); id++) {
         auto& sSensor = settings[id];
         auto& rSensor = results[id];
 
         if (sSensor.purpose == purpose && (!onlyConnected || rSensor.connected)) {
-          value += rSensor.values[valueId];
+          sum += rSensor.values[valueId];
           amount++;
         }
       }
 
-      if (!amount) {
-        return 0.0f;
-        
-      } else if (amount == 1) {
-        return value;
-
-      } else {
-        return value / amount;
-      }
+      value = amount == 1 ? sum : (sum / amount);
 
     } else if (avgType == AverageType::MINIMUM) {
-      float value = NAN;
-
       for (uint8_t id = 0; id <= getMaxSensorId(); id++) {
         auto& sSensor = settings[id];
         auto& rSensor = results[id];
 
         if (sSensor.purpose == purpose && (!onlyConnected || rSensor.connected)) {
-          if (value == NAN || rSensor.values[valueId] < value) {
+          if (amount == 0 || rSensor.values[valueId] < value) {
             value = rSensor.values[valueId];
+            amount++;
           }
         }
       }
 
-      return value != NAN ? value : 0.0f;
-
     } else if (avgType == AverageType::MAXIMUM) {
-      float value = NAN;
-
       for (uint8_t id = 0; id <= getMaxSensorId(); id++) {
         auto& sSensor = settings[id];
         auto& rSensor = results[id];
 
         if (sSensor.purpose == purpose && (!onlyConnected || rSensor.connected)) {
-          if (value == NAN || rSensor.values[valueId] > value) {
+          if (amount == 0 || rSensor.values[valueId] > value) {
             value = rSensor.values[valueId];
+            amount++;
           }
         }
       }
-
-      return value != NAN ? value : 0.0f;
-
-    } else {
-      // bad mean type
-      return 0.0f;
     }
+
+    return amount > 0 ? value : defaultValue;
   }
 
   static bool existsConnectedSensorsByPurpose(Purpose purpose) {
diff --git a/src/SensorsTask.h b/src/SensorsTask.h
index 09b0333..905bd88 100644
--- a/src/SensorsTask.h
+++ b/src/SensorsTask.h
@@ -423,14 +423,50 @@ protected:
   }
 
   void updateMasterValues() {
-    vars.master.heating.outdoorTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::OUTDOOR_TEMP, Sensors::ValueType::PRIMARY, settings.heating.outdoorTempAvgType);
-    vars.master.heating.indoorTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::INDOOR_TEMP, Sensors::ValueType::PRIMARY, settings.heating.indoorTempAvgType);
+    vars.master.heating.indoorTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::INDOOR_TEMP,
+      Sensors::ValueType::PRIMARY,
+      settings.heating.indoorTempAvgType,
+      true,
+      0.0f
+    );
+    vars.master.heating.outdoorTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::OUTDOOR_TEMP,
+      Sensors::ValueType::PRIMARY,
+      settings.heating.outdoorTempAvgType,
+      true,
+      0.0f
+    );
 
-    vars.master.heating.currentTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::HEATING_TEMP, Sensors::ValueType::PRIMARY);
-    vars.master.heating.returnTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::HEATING_RETURN_TEMP, Sensors::ValueType::PRIMARY);
+    vars.master.heating.currentTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::HEATING_TEMP,
+      Sensors::ValueType::PRIMARY,
+      Sensors::AverageType::MEAN,
+      true,
+      0.0f
+    );
+    vars.master.heating.returnTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::HEATING_RETURN_TEMP,
+      Sensors::ValueType::PRIMARY,
+      Sensors::AverageType::MEAN,
+      true,
+      0.0f
+    );
 
-    vars.master.dhw.currentTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::DHW_TEMP, Sensors::ValueType::PRIMARY);
-    vars.master.dhw.returnTemp = Sensors::getMeanValueByPurpose(Sensors::Purpose::DHW_RETURN_TEMP, Sensors::ValueType::PRIMARY);
+    vars.master.dhw.currentTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::DHW_TEMP,
+      Sensors::ValueType::PRIMARY,
+      Sensors::AverageType::MEAN,
+      true,
+      0.0f
+    );
+    vars.master.dhw.returnTemp = Sensors::getMeanValueByPurpose(
+      Sensors::Purpose::DHW_RETURN_TEMP,
+      Sensors::ValueType::PRIMARY,
+      Sensors::AverageType::MEAN,
+      true,
+      0.0f
+    );
   }
 
   void makeDallasInstances() {