1. Turn the heater off
2. Push and hold the button with three wavy lines while you turn the heater on again
3. You can let go off both buttons when you see the display resetting (blinking lights in the display)
4. The heater will start at the standard temperature of 22 degrees Celsius
AB-H700MINI and JA-series (JA1000, JA1500, JA2000) does need to be reset as they have a mechanical thermostat.