diff --git a/lib/BufferedWebServer/BufferedWebServer.h b/lib/BufferedWebServer/BufferedWebServer.h
index a991556..66edaed 100644
--- a/lib/BufferedWebServer/BufferedWebServer.h
+++ b/lib/BufferedWebServer/BufferedWebServer.h
@@ -77,10 +77,19 @@ public:
       return;
     }
 
-    this->webServer->sendContent((const char*)this->buffer, this->bufferPos);
-    this->bufferPos = 0;
     #ifdef ARDUINO_ARCH_ESP8266
-    ::delay(0);
+    ::optimistic_yield(1000);
+    #endif
+
+    auto& client = this->webServer->client();
+    if (client.connected()) {
+      this->webServer->sendContent((const char*)this->buffer, this->bufferPos);
+    }
+
+    this->bufferPos = 0;
+
+    #ifdef ARDUINO_ARCH_ESP8266
+    ::optimistic_yield(1000);
     #endif
   }
 
diff --git a/src/HaHelper.h b/src/HaHelper.h
index 94c434c..989117d 100644
--- a/src/HaHelper.h
+++ b/src/HaHelper.h
@@ -37,7 +37,7 @@ public:
       case Sensors::Purpose::DHW_RETURN_TEMP:
       case Sensors::Purpose::EXHAUST_TEMP:
       case Sensors::Purpose::TEMPERATURE:
-        doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+        doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
         if (unit == UnitSystem::METRIC) {
           doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
 
@@ -87,7 +87,7 @@ public:
         break;
 
       case Sensors::Purpose::HUMIDITY:
-        doc[FPSTR(HA_DEVICE_CLASS)] = F("humidity");
+        doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_HUMIDITY);
         doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_PERCENT);
         break;
 
@@ -156,23 +156,25 @@ public:
     String objId = Sensors::makeObjectId(sSensor.name);
 
     // state topic
-    doc[FPSTR(HA_STATE_TOPIC)] = this->getDeviceTopic(F("sensors"), objId.c_str());
+    doc[FPSTR(HA_STATE_TOPIC)] = this->getDeviceTopic(
+      F("sensors"),
+      objId.c_str()
+    );
 
     // set device class, name, value template for bluetooth sensors
     // or name & value template for another sensors
-    String sName = sSensor.name;
-    
     if (sSensor.type == Sensors::Type::BLUETOOTH) {
       // available state topic
       doc[FPSTR(HA_AVAILABILITY)][1][FPSTR(HA_TOPIC)] = doc[FPSTR(HA_STATE_TOPIC)];
       doc[FPSTR(HA_AVAILABILITY)][1][FPSTR(HA_VALUE_TEMPLATE)] = AVAILABILITY_SENSOR_CONN;
 
+      String sName = sSensor.name;
       switch (vType) {
         case Sensors::ValueType::TEMPERATURE:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("temp"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, F("temp"));
           sName += F(" temperature");
 
-          doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+          doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
           if (unit == UnitSystem::METRIC) {
             doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
             
@@ -184,20 +186,20 @@ public:
           break;
 
         case Sensors::ValueType::HUMIDITY:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("humidity"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_HUMIDITY));
           sName += F(" humidity");
 
-          doc[FPSTR(HA_DEVICE_CLASS)] = F("humidity");
+          doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_HUMIDITY);
           doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_PERCENT);
           doc[FPSTR(HA_NAME)] = sName;
           doc[FPSTR(HA_VALUE_TEMPLATE)] = F("{{ value_json.humidity|float(0)|round(2) }}");
           break;
 
         case Sensors::ValueType::BATTERY:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("battery"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_BATTERY));
           sName += F(" battery");
           
-          doc[FPSTR(HA_DEVICE_CLASS)] = F("battery");
+          doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_BATTERY);
           doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_DIAGNOSTIC);
           doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_PERCENT);
           doc[FPSTR(HA_NAME)] = sName;
@@ -205,7 +207,7 @@ public:
           break;
 
         case Sensors::ValueType::RSSI:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("rssi"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_RSSI));
           sName += F(" RSSI");
           
           doc[FPSTR(HA_DEVICE_CLASS)] = F("signal_strength");
@@ -223,10 +225,14 @@ public:
       doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
       doc[FPSTR(HA_MODE)] = FPSTR(HA_MODE_BOX);
 
-      doc[FPSTR(HA_COMMAND_TOPIC)] = this->getDeviceTopic(F("sensors"), objId.c_str(), F("set"));
+      doc[FPSTR(HA_COMMAND_TOPIC)] = this->getDeviceTopic(
+        F("sensors"),
+        objId.c_str(),
+        F("set")
+      );
       doc[FPSTR(HA_COMMAND_TEMPLATE)] = F("{\"value\": {{ value }}}");
 
-      doc[FPSTR(HA_NAME)] = sName;
+      doc[FPSTR(HA_NAME)] = sSensor.name;
       doc[FPSTR(HA_VALUE_TEMPLATE)] = F("{{ value_json.value|float(0)|round(2) }}");
 
     } else {
@@ -234,20 +240,15 @@ public:
       doc[FPSTR(HA_AVAILABILITY)][1][FPSTR(HA_TOPIC)] = doc[FPSTR(HA_STATE_TOPIC)];
       doc[FPSTR(HA_AVAILABILITY)][1][FPSTR(HA_VALUE_TEMPLATE)] = AVAILABILITY_SENSOR_CONN;
 
-      doc[FPSTR(HA_NAME)] = sName;
+      doc[FPSTR(HA_NAME)] = sSensor.name;
       doc[FPSTR(HA_VALUE_TEMPLATE)] = F("{{ value_json.value|float(0)|round(2) }}");
     }
 
-    sName.clear();
-
     // object id's
-    {
-      String objIdWithPrefix = this->getObjectIdWithPrefix(objId.c_str());
-      doc[FPSTR(HA_UNIQUE_ID)] = objIdWithPrefix;
-      doc[FPSTR(HA_OBJECT_ID)] = objIdWithPrefix;
-    }
+    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(objId.c_str());
+    doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
 
-    String configTopic = this->makeConfigTopic(
+    const String& configTopic = this->makeConfigTopic(
       sSensor.type == Sensors::Type::MANUAL ? FPSTR(HA_ENTITY_NUMBER) : FPSTR(HA_ENTITY_SENSOR),
       objId.c_str()
     );
@@ -264,32 +265,35 @@ public:
   }
 
   bool deleteDynamicSensor(Sensors::Settings& sSensor, Sensors::ValueType vType = Sensors::ValueType::PRIMARY) {
-    String objId = Sensors::makeObjectId(sSensor.name);
+    String objId;
 
     if (sSensor.type == Sensors::Type::BLUETOOTH) {
       switch (vType) {
         case Sensors::ValueType::TEMPERATURE:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("temp"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, F("temp"));
           break;
 
         case Sensors::ValueType::HUMIDITY:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("humidity"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_HUMIDITY));
           break;
 
         case Sensors::ValueType::BATTERY:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("battery"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_BATTERY));
           break;
 
         case Sensors::ValueType::RSSI:
-          objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("rssi"));
+          Sensors::makeObjectIdWithSuffix(objId, sSensor.name, FPSTR(S_RSSI));
           break;
 
         default:
           return false;
       }
+
+    } else {
+      Sensors::makeObjectId(objId, sSensor.name);
     }
 
-    String configTopic = this->makeConfigTopic(
+    const String& configTopic = this->makeConfigTopic(
       sSensor.type == Sensors::Type::MANUAL ? FPSTR(HA_ENTITY_NUMBER) : FPSTR(HA_ENTITY_SENSOR),
       objId.c_str()
     );
@@ -303,18 +307,14 @@ public:
     String objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("connected"));
 
     // object id's
-    {
-      String objIdWithPrefix = this->getObjectIdWithPrefix(objId.c_str());
-      doc[FPSTR(HA_UNIQUE_ID)] = objIdWithPrefix;
-      doc[FPSTR(HA_OBJECT_ID)] = objIdWithPrefix;
-    }
+    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(objId.c_str());
+    doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
 
     // state topic
-    {
-      String parentObjId = Sensors::makeObjectId(sSensor.name);
-      String stateTopic = this->getDeviceTopic(F("sensors"), parentObjId.c_str());
-      doc[FPSTR(HA_STATE_TOPIC)] = stateTopic;
-    }
+    doc[FPSTR(HA_STATE_TOPIC)] = this->getDeviceTopic(
+      F("sensors"),
+      Sensors::makeObjectId(sSensor.name).c_str()
+    );
 
     // sensor name
     {
@@ -325,7 +325,7 @@ public:
       doc[FPSTR(HA_NAME)] = sName;
     }
     
-    String configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_BINARY_SENSOR), objId.c_str());
+    const String& configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_BINARY_SENSOR), objId.c_str());
     objId.clear();
 
 
@@ -341,9 +341,10 @@ public:
   }
 
   bool deleteConnectionDynamicSensor(Sensors::Settings& sSensor) {
-    String objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("connected"));
-    String configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_BINARY_SENSOR), objId.c_str());
-    objId.clear();
+    const String& configTopic = this->makeConfigTopic(
+      FPSTR(HA_ENTITY_BINARY_SENSOR),
+      Sensors::makeObjectIdWithSuffix(sSensor.name, F("connected")).c_str()
+    );
 
     return this->publish(configTopic.c_str());
   }
@@ -353,18 +354,14 @@ public:
     String objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("signal_quality"));
 
     // object id's
-    {
-      String objIdWithPrefix = this->getObjectIdWithPrefix(objId.c_str());
-      doc[FPSTR(HA_UNIQUE_ID)] = objIdWithPrefix;
-      doc[FPSTR(HA_OBJECT_ID)] = objIdWithPrefix;
-    }
+    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(objId.c_str());
+    doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
 
     // state topic
-    {
-      String parentObjId = Sensors::makeObjectId(sSensor.name);
-      String stateTopic = this->getDeviceTopic(F("sensors"), parentObjId.c_str());
-      doc[FPSTR(HA_STATE_TOPIC)] = stateTopic;
-    }
+    doc[FPSTR(HA_STATE_TOPIC)] = this->getDeviceTopic(
+      F("sensors"),
+      Sensors::makeObjectId(sSensor.name).c_str()
+    );
 
     // sensor name
     {
@@ -375,7 +372,7 @@ public:
       doc[FPSTR(HA_NAME)] = sName;
     }
     
-    String configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_SENSOR), objId.c_str());
+    const String& configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_SENSOR), objId.c_str());
     objId.clear();
 
 
@@ -395,9 +392,10 @@ public:
 
   bool deleteSignalQualityDynamicSensor(Sensors::Settings& sSensor) {
     JsonDocument doc;
-    String objId = Sensors::makeObjectIdWithSuffix(sSensor.name, F("signal_quality"));
-    String configTopic = this->makeConfigTopic(FPSTR(HA_ENTITY_SENSOR), objId.c_str());
-    objId.clear();
+    const String& configTopic = this->makeConfigTopic(
+      FPSTR(HA_ENTITY_SENSOR),
+      Sensors::makeObjectIdWithSuffix(sSensor.name, F("signal_quality")).c_str()
+    );
 
     return this->publish(configTopic.c_str());
   }
@@ -432,7 +430,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("heating_hysteresis"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -488,7 +486,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("heating_min_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -522,7 +520,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("heating_max_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -557,7 +555,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("dhw_min_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -591,7 +589,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("dhw_max_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -742,7 +740,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("pid_min_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -776,7 +774,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("pid_max_temp"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("temperature");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_TEMPERATURE);
 
     if (unit == UnitSystem::METRIC) {
       doc[FPSTR(HA_UNIT_OF_MEASUREMENT)] = FPSTR(HA_UNIT_OF_MEASUREMENT_C);
@@ -1119,7 +1117,7 @@ public:
     JsonDocument doc;
     doc[FPSTR(HA_AVAILABILITY)][FPSTR(HA_TOPIC)] = this->statusTopic.c_str();
     doc[FPSTR(HA_ENABLED_BY_DEFAULT)] = enabledByDefault;
-    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("rssi"));
+    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(FPSTR(S_RSSI));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_DIAGNOSTIC);
     doc[FPSTR(HA_DEVICE_CLASS)] = F("signal_strength");
@@ -1132,7 +1130,7 @@ public:
     doc[FPSTR(HA_EXPIRE_AFTER)] = this->expireAfter;
     doc.shrinkToFit();
 
-    return this->publish(this->makeConfigTopic(FPSTR(HA_ENTITY_SENSOR), F("rssi")).c_str(), doc);
+    return this->publish(this->makeConfigTopic(FPSTR(HA_ENTITY_SENSOR), FPSTR(S_RSSI)).c_str(), doc);
   }
 
   bool publishUptime(bool enabledByDefault = true) {
@@ -1257,17 +1255,17 @@ public:
     JsonDocument doc;
     doc[FPSTR(HA_AVAILABILITY)][FPSTR(HA_TOPIC)] = this->statusTopic.c_str();
     doc[FPSTR(HA_ENABLED_BY_DEFAULT)] = enabledByDefault;
-    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("restart"));
+    doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(FPSTR(S_RESTART));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("restart");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_RESTART);
     doc[FPSTR(HA_NAME)] = F("Restart");
     doc[FPSTR(HA_COMMAND_TOPIC)] = this->setStateTopic.c_str();
     doc[FPSTR(HA_COMMAND_TEMPLATE)] = F("{\"actions\": {\"restart\": true}}");
     doc[FPSTR(HA_EXPIRE_AFTER)] = this->expireAfter;
     doc.shrinkToFit();
 
-    return this->publish(this->makeConfigTopic(FPSTR(HA_ENTITY_BUTTON), F("restart")).c_str(), doc);
+    return this->publish(this->makeConfigTopic(FPSTR(HA_ENTITY_BUTTON), FPSTR(S_RESTART)).c_str(), doc);
   }
 
   bool publishResetFaultButton(bool enabledByDefault = true) {
@@ -1280,7 +1278,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("reset_fault"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("restart");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_RESTART);
     doc[FPSTR(HA_NAME)] = F("Reset fault");
     doc[FPSTR(HA_COMMAND_TOPIC)] = this->setStateTopic.c_str();
     doc[FPSTR(HA_COMMAND_TEMPLATE)] = F("{\"actions\": {\"resetFault\": true}}");
@@ -1300,7 +1298,7 @@ public:
     doc[FPSTR(HA_UNIQUE_ID)] = this->getObjectIdWithPrefix(F("reset_diagnostic"));
     doc[FPSTR(HA_OBJECT_ID)] = doc[FPSTR(HA_UNIQUE_ID)];
     doc[FPSTR(HA_ENTITY_CATEGORY)] = FPSTR(HA_ENTITY_CATEGORY_CONFIG);
-    doc[FPSTR(HA_DEVICE_CLASS)] = F("restart");
+    doc[FPSTR(HA_DEVICE_CLASS)] = FPSTR(S_RESTART);
     doc[FPSTR(HA_NAME)] = F("Reset diagnostic");
     doc[FPSTR(HA_COMMAND_TOPIC)] = this->setStateTopic.c_str();
     doc[FPSTR(HA_COMMAND_TEMPLATE)] = F("{\"actions\": {\"resetDiagnostic\": true}}");
diff --git a/src/MainTask.h b/src/MainTask.h
index 7c238f6..09795aa 100644
--- a/src/MainTask.h
+++ b/src/MainTask.h
@@ -76,17 +76,6 @@ protected:
       vars.actions.restart = false;
       this->restartSignalTime = millis();
 
-      // save settings
-      fsSettings.updateNow();
-
-      // save sensors settings
-      fsSensorsSettings.updateNow();
-
-      // force save network settings
-      if (fsNetworkSettings.updateNow() == FD_FILE_ERR && LittleFS.begin()) {
-        fsNetworkSettings.write();
-      }
-
       Log.sinfoln(FPSTR(L_MAIN), F("Restart signal received. Restart after 10 sec."));
     }
 
@@ -147,8 +136,9 @@ protected:
     for (Stream* stream : Log.getStreams()) {
       while (stream->available() > 0) {
         stream->read();
+
         #ifdef ARDUINO_ARCH_ESP8266
-        ::delay(0);
+        ::optimistic_yield(1000);
         #endif
       }
     }
@@ -159,7 +149,19 @@ protected:
 
     // restart
     if (this->restartSignalTime > 0 && millis() - this->restartSignalTime > 10000) {
+      // save settings
+      fsSettings.updateNow();
+
+      // save sensors settings
+      fsSensorsSettings.updateNow();
+
+      // force save network settings
+      if (fsNetworkSettings.updateNow() == FD_FILE_ERR && LittleFS.begin()) {
+        fsNetworkSettings.write();
+      }
+
       this->restartSignalTime = 0;
+      this->delay(500);
       ESP.restart();
     }
   }
diff --git a/src/MqttTask.h b/src/MqttTask.h
index b201ace..a85c7e5 100644
--- a/src/MqttTask.h
+++ b/src/MqttTask.h
@@ -129,7 +129,7 @@ protected:
     #endif
 
     this->client->onMessage([this] (void*, size_t length) {
-      String topic = this->client->messageTopic();
+      const String& topic = this->client->messageTopic();
       if (!length || length > 2048 || !topic.length()) {
         return;
       }
@@ -139,7 +139,7 @@ protected:
         payload[i] = this->client->read();
       }
       
-      this->onMessage(topic.c_str(), payload, length);
+      this->onMessage(topic, payload, length);
     });
 
     // writer settings
@@ -153,7 +153,7 @@ protected:
       Log.straceln(FPSTR(L_MQTT), F("%s publish %u of %u bytes to topic: %s"), result ? F("Successfully") : F("Failed"), written, length, topic);
 
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
 
       //this->client->poll();
@@ -162,13 +162,13 @@ protected:
 
     #ifdef ARDUINO_ARCH_ESP8266
     this->writer->setFlushEventCallback([this] (size_t, size_t) {
-      ::delay(0);
+      ::optimistic_yield(1000);
 
       if (this->wifiClient->connected()) {
         this->wifiClient->flush();
       }
 
-      ::delay(0);
+      ::optimistic_yield(1000);
     });
     #endif
 
@@ -222,7 +222,7 @@ protected:
     }
 
     #ifdef ARDUINO_ARCH_ESP8266
-    ::delay(0);
+    ::optimistic_yield(1000);
     #endif
 
     // publish variables and status
@@ -295,14 +295,14 @@ protected:
               this->haHelper->deleteDynamicSensor(prevSettings, Sensors::ValueType::TEMPERATURE);
               break;
             
-            case Sensors::Type::MANUAL: {
-              String topic = this->haHelper->getDeviceTopic(
-                F("sensors"),
-                Sensors::makeObjectId(prevSettings.name).c_str(),
-                F("set")
+            case Sensors::Type::MANUAL:
+              this->client->unsubscribe(
+                this->haHelper->getDeviceTopic(
+                  F("sensors"),
+                  Sensors::makeObjectId(prevSettings.name).c_str(),
+                  F("set")
+                ).c_str()
               );
-              this->client->unsubscribe(topic.c_str());
-            }
 
             default:
               this->haHelper->deleteDynamicSensor(prevSettings, Sensors::ValueType::PRIMARY);
@@ -331,14 +331,14 @@ protected:
             this->haHelper->publishDynamicSensor(sSettings, Sensors::ValueType::TEMPERATURE, settings.system.unitSystem);
             break;
 
-          case Sensors::Type::MANUAL: {
-            String topic = this->haHelper->getDeviceTopic(
-              F("sensors"),
-              Sensors::makeObjectId(prevSettings.name).c_str(),
-              F("set")
+          case Sensors::Type::MANUAL: 
+            this->client->subscribe(
+              this->haHelper->getDeviceTopic(
+                F("sensors"),
+                Sensors::makeObjectId(prevSettings.name).c_str(),
+                F("set")
+              ).c_str()
             );
-            this->client->subscribe(topic.c_str());
-          }
           
           default:
             this->haHelper->publishDynamicSensor(sSettings, Sensors::ValueType::PRIMARY, settings.system.unitSystem);
@@ -372,13 +372,13 @@ protected:
     Log.swarningln(FPSTR(L_MQTT), F("Disconnected (reason: %d uptime: %lu s.)"), this->client->connectError(), uptime);
   }
 
-  void onMessage(const char* topic, uint8_t* payload, size_t length) {
+  void onMessage(const String& topic, uint8_t* payload, size_t length) {
     if (!length) {
       return;
     }
 
     if (settings.system.logLevel >= TinyLogger::Level::TRACE) {
-      Log.strace(FPSTR(L_MQTT_MSG), F("Topic: %s\r\n>  "), topic);
+      Log.strace(FPSTR(L_MQTT_MSG), F("Topic: %s\r\n>  "), topic.c_str());
       if (Log.lock()) {
         for (size_t i = 0; i < length; i++) {
           if (payload[i] == 0) {
@@ -409,31 +409,27 @@ protected:
     }
     doc.shrinkToFit();
 
+    // delete topic
+    this->writer->publish(topic.c_str(), nullptr, 0, true);
+
     if (this->haHelper->getDeviceTopic(F("state/set")).equals(topic)) {
-      this->writer->publish(topic, nullptr, 0, true);
-      
       if (jsonToVars(doc, vars)) {
         this->resetPublishedVarsTime();
       }
 
     } else if (this->haHelper->getDeviceTopic(F("settings/set")).equals(topic)) {
-      this->writer->publish(topic, nullptr, 0, true);
-      
       if (safeJsonToSettings(doc, settings)) {
         this->resetPublishedSettingsTime();
         fsSettings.update();
       }
 
     } else {
-      this->writer->publish(topic, nullptr, 0, true);
-
-      String _topic = topic;
-      String sensorsTopic = this->haHelper->getDeviceTopic(F("sensors/"));
+      const String& sensorsTopic = this->haHelper->getDeviceTopic(F("sensors/"));
       auto stLength = sensorsTopic.length();
 
-      if (_topic.startsWith(sensorsTopic) && _topic.endsWith(F("/set"))) {
-        if (_topic.length() > stLength + 4) {
-          String name = _topic.substring(stLength, _topic.indexOf('/', stLength));
+      if (topic.startsWith(sensorsTopic) && topic.endsWith(F("/set"))) {
+        if (topic.length() > stLength + 4) {
+          const String& name = topic.substring(stLength, topic.indexOf('/', stLength));
           int16_t id = Sensors::getIdByObjectId(name.c_str());
 
           if (id == -1) {
@@ -515,14 +511,14 @@ protected:
           this->haHelper->publishDynamicSensor(sSettings, Sensors::ValueType::TEMPERATURE, settings.system.unitSystem);
           break;
 
-        case Sensors::Type::MANUAL: {
-          String topic = this->haHelper->getDeviceTopic(
-            F("sensors"),
-            Sensors::makeObjectId(sSettings.name).c_str(),
-            F("set")
+        case Sensors::Type::MANUAL:
+          this->client->subscribe(
+            this->haHelper->getDeviceTopic(
+              F("sensors"),
+              Sensors::makeObjectId(sSettings.name).c_str(),
+              F("set")
+            ).c_str()
           );
-          this->client->subscribe(topic.c_str());
-        }
         
         default:
           this->haHelper->publishDynamicSensor(sSettings, Sensors::ValueType::PRIMARY, settings.system.unitSystem);
@@ -603,12 +599,14 @@ protected:
     sensorResultToJson(sensorId, doc);
     doc.shrinkToFit();
 
-    String topic = this->haHelper->getDeviceTopic(
-      F("sensors"),
-      Sensors::makeObjectId(sSettings.name).c_str()
+    return this->writer->publish(
+      this->haHelper->getDeviceTopic(
+        F("sensors"),
+        Sensors::makeObjectId(sSettings.name).c_str()
+      ).c_str(),
+      doc,
+      true
     );
-    
-    return this->writer->publish(topic.c_str(), doc, true);
   }
 
   bool publishVariables(const char* topic) {
diff --git a/src/PortalTask.h b/src/PortalTask.h
index baed4de..fd1a2b2 100644
--- a/src/PortalTask.h
+++ b/src/PortalTask.h
@@ -232,7 +232,7 @@ protected:
         }
       }
 
-      String plain = this->webServer->arg(0);
+      const String& plain = this->webServer->arg(0);
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Request /api/backup/restore %d bytes: %s"), plain.length(), plain.c_str());
 
       if (plain.length() < 5) {
@@ -246,7 +246,6 @@ protected:
 
       JsonDocument doc;
       DeserializationError dErr = deserializeJson(doc, plain);
-      plain.clear();
 
       if (dErr != DeserializationError::Ok || doc.isNull() || !doc.size()) {
         this->webServer->send(400);
@@ -254,12 +253,6 @@ protected:
       }
 
       bool changed = false;
-      if (!doc[FPSTR(S_SETTINGS)].isNull() && jsonToSettings(doc[FPSTR(S_SETTINGS)], settings)) {
-        vars.actions.restart = true;
-        fsSettings.update();
-        changed = true;
-      }
-
       if (!doc[FPSTR(S_NETWORK)].isNull() && jsonToNetworkSettings(doc[FPSTR(S_NETWORK)], networkSettings)) {
         fsNetworkSettings.update();
         network->setHostname(networkSettings.hostname)
@@ -271,27 +264,40 @@ protected:
             networkSettings.staticConfig.gateway,
             networkSettings.staticConfig.subnet,
             networkSettings.staticConfig.dns
-          )
-          ->reconnect();
+          );
+        changed = true;
+      }
+
+      if (!doc[FPSTR(S_SETTINGS)].isNull() && jsonToSettings(doc[FPSTR(S_SETTINGS)], settings)) {
+        fsSettings.update();
         changed = true;
       }
 
       if (!doc[FPSTR(S_SENSORS)].isNull()) {
-        for (uint8_t sensorId = 0; sensorId <= Sensors::getMaxSensorId(); sensorId++) {
-          if (doc[FPSTR(S_SENSORS)][sensorId].isNull()) {
+        for (auto sensor : doc[FPSTR(S_SENSORS)].as<JsonObject>()) {
+          if (!isDigit(sensor.key().c_str())) {
             continue;
           }
 
-          auto sensorSettingsDoc = doc[FPSTR(S_SENSORS)][sensorId].to<JsonObject>();
-          if (jsonToSensorSettings(sensorId, sensorSettingsDoc, Sensors::settings[sensorId])){
+          int sensorId = atoi(sensor.key().c_str());
+          if (sensorId < 0 || sensorId > 255 || !Sensors::isValidSensorId(sensorId)) {
+            continue;
+          }
+          
+          if (jsonToSensorSettings(sensorId, sensor.value(), Sensors::settings[sensorId])) {
+            fsSensorsSettings.update();
             changed = true;
           }
         }
       }
-
+      
       doc.clear();
       doc.shrinkToFit();
 
+      if (changed) {
+        vars.actions.restart = true;
+      }
+
       this->webServer->send(changed ? 201 : 200);
     });
 
@@ -317,7 +323,7 @@ protected:
         }
       }
 
-      String plain = this->webServer->arg(0);
+      const String& plain = this->webServer->arg(0);
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Request /api/network/settings %d bytes: %s"), plain.length(), plain.c_str());
 
       if (plain.length() < 5) {
@@ -331,7 +337,6 @@ protected:
 
       JsonDocument doc;
       DeserializationError dErr = deserializeJson(doc, plain);
-      plain.clear();
 
       if (dErr != DeserializationError::Ok || doc.isNull() || !doc.size()) {
         this->webServer->send(400);
@@ -390,7 +395,7 @@ protected:
       
       JsonDocument doc;
       for (short int i = 0; i < apCount; i++) {
-        String ssid = WiFi.SSID(i);
+        const String& ssid = WiFi.SSID(i);
         doc[i][FPSTR(S_SSID)] = ssid;
         doc[i][FPSTR(S_BSSID)] = WiFi.BSSIDstr(i);
         doc[i][FPSTR(S_SIGNAL_QUALITY)] = NetworkMgr::rssiToSignalQuality(WiFi.RSSI(i));
@@ -433,7 +438,7 @@ protected:
         }
       }
 
-      String plain = this->webServer->arg(0);
+      const String& plain = this->webServer->arg(0);
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Request /api/settings %d bytes: %s"), plain.length(), plain.c_str());
 
       if (plain.length() < 5) {
@@ -447,7 +452,6 @@ protected:
 
       JsonDocument doc;
       DeserializationError dErr = deserializeJson(doc, plain);
-      plain.clear();
 
       if (dErr != DeserializationError::Ok || doc.isNull() || !doc.size()) {
         this->webServer->send(400);
@@ -618,7 +622,7 @@ protected:
         }
       }
 
-      String plain = this->webServer->arg(0);
+      const String& plain = this->webServer->arg(0);
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Request /api/vars %d bytes: %s"), plain.length(), plain.c_str());
 
       if (plain.length() < 5) {
@@ -632,7 +636,6 @@ protected:
 
       JsonDocument doc;
       DeserializationError dErr = deserializeJson(doc, plain);
-      plain.clear();
 
       if (dErr != DeserializationError::Ok || doc.isNull() || !doc.size()) {
         this->webServer->send(400);
@@ -829,7 +832,7 @@ protected:
     this->webServer->onNotFound([this]() {
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Page not found, uri: %s"), this->webServer->uri().c_str());
 
-      const String uri = this->webServer->uri();
+      const String& uri = this->webServer->uri();
       if (uri.equals(F("/"))) {
         this->webServer->send(200, F("text/plain"), F("The file system is not flashed!"));
 
@@ -856,7 +859,7 @@ protected:
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Started: AP up or STA connected"));
 
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
 
     } else if (this->stateWebServer() && !network->isApEnabled() && !network->isStaEnabled()) {
@@ -864,7 +867,7 @@ protected:
       Log.straceln(FPSTR(L_PORTAL_WEBSERVER), F("Stopped: AP and STA down"));
 
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
     }
 
@@ -874,7 +877,7 @@ protected:
       Log.straceln(FPSTR(L_PORTAL_DNSSERVER), F("Started: AP up"));
       
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
 
     } else if (this->stateDnsServer() && (!network->isApEnabled() || !this->stateWebServer())) {
@@ -882,14 +885,15 @@ protected:
       Log.straceln(FPSTR(L_PORTAL_DNSSERVER), F("Stopped: AP down"));
 
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
     }
 
     if (this->stateDnsServer()) {
       this->dnsServer->processNextRequest();
+
       #ifdef ARDUINO_ARCH_ESP8266
-      ::delay(0);
+      ::optimistic_yield(1000);
       #endif
     }
 
@@ -907,7 +911,7 @@ protected:
   }
 
   void onCaptivePortal() {
-    const String uri = this->webServer->uri();
+    const String& uri = this->webServer->uri();
 
     if (uri.equals(F("/connecttest.txt"))) {
       this->webServer->sendHeader(F("Location"), F("http://logout.net"));
@@ -927,10 +931,10 @@ protected:
 
     } else {
       String portalUrl = F("http://");
-      portalUrl += network->getApIp().toString();
+      portalUrl += network->getApIp().toString().c_str();
       portalUrl += '/';
 
-      this->webServer->sendHeader(F("Location"), portalUrl.c_str());
+      this->webServer->sendHeader(F("Location"), portalUrl);
       this->webServer->send(302);
 
       Log.straceln(FPSTR(L_PORTAL_CAPTIVE), F("Redirect to portal page with 302 code"));
diff --git a/src/Sensors.h b/src/Sensors.h
index 4c6735c..ed06f34 100644
--- a/src/Sensors.h
+++ b/src/Sensors.h
@@ -146,9 +146,10 @@ public:
       return 0;
     }
 
+    String refObjectId;
     for (uint8_t id = 0; id < getMaxSensorId(); id++) {
-      String _objectId = Sensors::makeObjectId(settings[id].name);
-      if (strcmp(_objectId.c_str(), objectId) == 0) {
+      Sensors::makeObjectId(refObjectId, settings[id].name);
+      if (refObjectId.equals(objectId)) {
         return id;
       }
     }
@@ -351,13 +352,10 @@ public:
     return false;
   }
 
-  template <class T> 
-  static String cleanName(T value, char space = ' ') {
-    String clean = value;
-
+  static String& cleanName(String& value, char space = ' ') {
     // only valid symbols
-    for (uint8_t pos = 0; pos < clean.length(); pos++) {
-      char symbol = clean.charAt(pos);
+    for (uint8_t pos = 0; pos < value.length(); pos++) {
+      char symbol = value.charAt(pos);
 
       // 0..9
       if (symbol >= 48 && symbol <= 57) {
@@ -379,39 +377,68 @@ public:
         continue;
       }
 
-      clean.setCharAt(pos, space);
+      value.setCharAt(pos, space);
     }
 
-    clean.trim();
+    value.trim();
 
-    return clean;
+    return value;
+  }
+
+  template <class T> 
+  static String cleanName(T value, char space = ' ') {
+    String res = value;
+    return cleanName(res, space);
+  }
+
+  template <class T> 
+  static String& makeObjectId(String& res, T value, char separator = '_') {
+    res = value;
+    cleanName(res);
+    res.toLowerCase();
+    res.replace(' ', separator);
+
+    return res;
   }
 
   template <class T> 
   static String makeObjectId(T value, char separator = '_') {
-    auto objId = cleanName(value);
-    objId.toLowerCase();
-    objId.replace(' ', separator);
+    String res;
+    makeObjectId(res, value, separator);
 
-    return objId;
+    return res;
   }
 
   template <class TV, class TS> 
-  static auto makeObjectIdWithSuffix(TV value, TS suffix, char separator = '_') {
-    auto objId = makeObjectId(value, separator);
-    objId += separator;
-    objId += suffix;
+  static String& makeObjectIdWithSuffix(String& res, TV value, TS suffix, char separator = '_') {
+    res.clear();
+    makeObjectId(res, value, separator);
+    res += separator;
+    res += suffix;
 
-    return objId;
+    return res;
+  }
+
+  template <class TV, class TS> 
+  static String makeObjectIdWithSuffix(TV value, TS suffix, char separator = '_') {
+    String res;
+    makeObjectIdWithSuffix(res, value, suffix, separator);
+    return res;
   }
 
   template <class TV, class TP> 
-  static auto makeObjectIdWithPrefix(TV value, TP prefix, char separator = '_') {
-    String objId = prefix;
-    objId += separator;
-    objId += makeObjectId(value, separator);
+  static String& makeObjectIdWithPrefix(String& res, TV value, TP prefix, char separator = '_') {
+    res = prefix;
+    res += separator;
+    res += makeObjectId(value, separator).c_str();
 
-    return objId;
+    return res;
+  }
+
+  template <class TV, class TP> 
+  static String makeObjectIdWithPrefix(TV value, TP prefix, char separator = '_') {
+    String res;
+    return makeObjectIdWithPrefix(res, value, prefix, separator);
   }
 
   static uint8_t bluetoothRssiToQuality(int rssi) {
diff --git a/src/Settings.h b/src/Settings.h
index 7b3f59b..0f22fff 100644
--- a/src/Settings.h
+++ b/src/Settings.h
@@ -154,7 +154,7 @@ Sensors::Settings sensorsSettings[SENSORS_AMOUNT] = {
     false,
     "Outdoor temp",
     Sensors::Purpose::OUTDOOR_TEMP,
-    Sensors::Type::DALLAS_TEMP,
+    Sensors::Type::OT_OUTDOOR_TEMP,
     DEFAULT_SENSOR_OUTDOOR_GPIO
   },
   {
diff --git a/src/utils.h b/src/utils.h
index 0eac8c7..d928a21 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -1461,7 +1461,8 @@ bool jsonToSensorSettings(const uint8_t sensorId, const JsonVariantConst src, Se
 
   // name
   if (!src[FPSTR(S_NAME)].isNull()) {
-    String value = Sensors::cleanName(src[FPSTR(S_NAME)].as<String>());
+    auto value = src[FPSTR(S_NAME)].as<String>();
+    Sensors::cleanName(value);
 
     if (value.length() < sizeof(dst.name) && !value.equals(dst.name)) {
       strcpy(dst.name, value.c_str());
diff --git a/src_data/scripts/utils.js b/src_data/scripts/utils.js
index 5bdc88d..122d273 100644
--- a/src_data/scripts/utils.js
+++ b/src_data/scripts/utils.js
@@ -306,22 +306,6 @@ const setupRestoreBackupForm = (formSelector) => {
       try {
         const data = JSON.parse(event.target.result);
         console.log("Backup: ", data);
-        
-        if (data.network != undefined) {
-          let response = await fetch(url, {
-            method: 'POST',
-            cache: 'no-cache',
-            headers: {
-              'Content-Type': 'application/json'
-            },
-            body: JSON.stringify({"network": data.network})
-          });
-
-          if (!response.ok) {
-            onFailed();
-            return;
-          }
-        }
 
         if (data.settings != undefined) {
           let response = await fetch(url, {
@@ -362,6 +346,22 @@ const setupRestoreBackupForm = (formSelector) => {
           }
         }
 
+        if (data.network != undefined) {
+          let response = await fetch(url, {
+            method: 'POST',
+            cache: 'no-cache',
+            headers: {
+              'Content-Type': 'application/json'
+            },
+            body: JSON.stringify({"network": data.network})
+          });
+
+          if (!response.ok) {
+            onFailed();
+            return;
+          }
+        }
+
         onSuccess();
 
       } catch (err) {