diff --git a/hotwater.ino b/hotwater.ino
index ca75a79..73d4037 100644
--- a/hotwater.ino
+++ b/hotwater.ino
@@ -27,10 +27,14 @@ IPAddress subnet(MY_NET);
 #define TCP_PORT 15000
 #define T_UPDATE_INTERVAL 1000
 
+#define MODE_OFF 0
+#define MODE_ON 1
+
 #define REGISTER_TARGET_T 0
 #define REGISTER_HYSTERESIS 1
 #define REGISTER_CUR_TEMP 2
 #define REGISTER_CUR_STATE 3
+#define REGISTER_MODE 4
 
 ModbusIP mb;
 OneWire oneWire(TEMP_SENSOR_PIN);
@@ -45,6 +49,7 @@ int t_target = 7000;
 int hyst = 200;
 int cur_t = 0;
 int cur_state = 0;
+int mode = 1;
 
 bool TryLoad(char *filename)
 {
@@ -54,6 +59,8 @@ bool TryLoad(char *filename)
 	t_target = atoi(s.c_str());
   s = f.readStringUntil('\n');
 	hyst = atoi(s.c_str());
+  s = f.readStringUntil('\n');
+	mode = atoi(s.c_str());
   f.close();
   if (t_target == 0) return false;
 	return true;
@@ -71,6 +78,7 @@ void SaveTo(char *filename)
 	if (!f) return;
 	f.println(t_target);
   f.println(hyst);
+  f.println(mode);
 	f.close();
 }
 
@@ -114,6 +122,7 @@ void setup()
 	mb.addHreg(REGISTER_HYSTERESIS, hyst);
 	mb.addHreg(REGISTER_CUR_TEMP, cur_t);
 	mb.addHreg(REGISTER_CUR_STATE, cur_state);
+  mb.addHreg(REGISTER_MODE, mode);
   //
   sensor.begin();
   sensor.setResolution(12);
@@ -141,10 +150,15 @@ void loop()
 	mb.task();
 	t_target = mb.Hreg(REGISTER_TARGET_T);
 	hyst = mb.Hreg(REGISTER_HYSTERESIS);
+  mode = mb.Hreg(REGISTER_MODE);
 	if (cur_t < t_target - hyst) cur_state = 1;
 	else if (cur_t > t_target + hyst) cur_state = 0;
 	mb.Hreg(REGISTER_CUR_STATE, cur_state);
-	digitalWrite(RELAY_PIN, cur_state);
+  if (mode == MODE_OFF)
+  {
+    cur_state = 0;
+  }
+  digitalWrite(RELAY_PIN, cur_state);
 	if (u) 
 	{
     SaveState();
@@ -157,11 +171,13 @@ void loop()
     lcd.print((cur_t) / 100.0, 2);
     lcd.print(" (");
     lcd.print(t_target / 100);
-    lcd.print(")");
+    lcd.print(") ");
+    if (mode == MODE_ON) lcd.print("ON");
+    else lcd.print("OFF");
     lcd.setCursor(0, 1);
     lcd.print("S: ");
     lcd.print(cur_state);
-    lcd.print("WiFi: ");
+    lcd.print(" WiFi: ");
     lcd.print(WiFi.status());
 	}
 	mb.Hreg(REGISTER_TARGET_T, t_target);