diff --git a/firmware/config.h b/firmware/config.h
index 1ecdf35..fa7e5ec 100644
--- a/firmware/config.h
+++ b/firmware/config.h
@@ -10,7 +10,7 @@
 #define DELAY_LOOP_MS                    50
 #define POWERSAVING_SLEEP_S             600
 #define EMERGENCY_SLEEP_S            172800 // Sleep for 2 days to recover
-#define RESET_ESP_TIME_INTERVAL_MS   (60*60*3*1000) // (60*60*6*1000) // reset every 3 hours
+#define RESET_ESP_TIME_INTERVAL_MS   (60*60*12*1000) // reset every 12 hours
 #define WIND_SENSOR_MEAS_TIME_S          15
 #define INITIAL_WEBSERVER_TIME           20
 
diff --git a/firmware/firmware.ino b/firmware/firmware.ino
index fbc636a..a7730ef 100644
--- a/firmware/firmware.ino
+++ b/firmware/firmware.ino
@@ -7,13 +7,16 @@
 #include <ESP8266HTTPClient.h>
 
 #include <WiFiClient.h>  // WiFiClient
-#include <WiFiManager.h> // WiFiManager from bib manager
 
 // Project includes
 #include "constants.h"
 #include "config.h"
 #include "config_user.h"
 
+#ifdef USE_WIFIMANAGER
+#include <WiFiManager.h> // WiFiManager from bib manager
+#endif
+
 //*************************************************************************//
 // check if some settings are correct
 
@@ -36,7 +39,9 @@ uint16_t update_windspeed_exceed_cnt = 0;
 
 boolean validData = false;
 
+#ifdef USE_WIFIMANAGER
 WiFiManager wifiManager;
+#endif
 
 //*************************************************************************//
 
@@ -141,7 +146,7 @@ void setup()
 
 #ifdef ENABLE_WATCHDOG
   // Enable the internal watchdog
-  ESP.wdtEnable(WATCHDOG_TIMEOUT_MS);
+  ESP.wdtEnable(WDTO_4S);
 #endif
 
 }
@@ -150,6 +155,9 @@ void setup()
 
 void wifiConnectionCheck()
 {
+
+#ifdef USE_WIFIMANAGER
+
   // Establish WiFi connection
   String wifiName = "oko-weather-" + DEVICE_NAME;
 
@@ -161,6 +169,7 @@ void wifiConnectionCheck()
 
   while (!wifiManager.autoConnect(wifiName.c_str(), "DEADBEEF"))
   {
+
     debug("WiFi connection failed, try again in 5 seconds...");
     // If autoconnect to WLAN failed and no client connected, go to deep sleep
 #ifdef SLEEP_IF_NO_WLAN_CONNECTION
@@ -173,6 +182,33 @@ void wifiConnectionCheck()
 #endif
   }
 
+#else // else of USE_WIFIMANAGER
+
+  if (WiFi.status() == WL_CONNECTED)
+  {
+    return;
+  }
+
+  if (!WiFi.config(local_IP, gateway, subnet))
+  {
+    Serial.println("Failed to set IP configuration");
+  } else {
+    Serial.println("Successful set IP configuration");
+  }
+
+  WiFi.begin(ssid, password);
+
+  Serial.println("Connecting to WLAN");
+
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    delay(100);
+  }
+
+  Serial.println("WLAN connection OK");
+
+#endif
+
 }
 
 //*************************************************************************//
diff --git a/firmware/webUpdater.ino b/firmware/webUpdater.ino
index 25af4b7..4514cdd 100644
--- a/firmware/webUpdater.ino
+++ b/firmware/webUpdater.ino
@@ -11,11 +11,14 @@
 #include <ESP8266HTTPUpdateServer.h>
 
 #include <WiFiClient.h>
-#include <WiFiManager.h>         // WiFiManager from bib manager
 
 #include "config.h"
 #include "config_user.h"
 
+#ifdef USE_WIFIMANAGER
+#include <WiFiManager.h>         // WiFiManager from bib manager
+#endif
+
 ESP8266WebServer httpServer(WEB_UPDATER_HTTP_PORT);
 ESP8266HTTPUpdateServer httpUpdater;
 
@@ -44,7 +47,9 @@ void setupWebUpdater(String device, String ip)
   httpUpdater.setup(&httpServer);
 
   httpServer.on("/", showHTMLMain);
+#ifdef USE_WIFIMANAGER
   httpServer.on("/resetWifiManager", resetWifiManager);
+#endif
 #ifdef HOMEBRIDGE_WEBSTAT
   httpServer.on("/hbWebstat", hb_webstat_send);
 #endif
@@ -70,7 +75,7 @@ void setSensorData(float sensorValues[])
   {
     if (sensorValues[i] != 0)
     {
-      wuValidData = true; // at least one value is not zero, the data
+      wuValidData = true; // at least one value is not zero, the data is valid
     }
   }
 
@@ -129,6 +134,7 @@ void hb_webstat_send(void)
   httpServer.send(200, "text/html", msg);
 }
 
+#ifdef USE_WIFIMANAGER
 void resetWifiManager()
 {
 
@@ -150,6 +156,7 @@ void resetWifiManager()
   // manual reset after restart is required
   ESP.restart();
 }
+#endif
 
 void measureWindspeed()
 {