I turned the top control to a point that the oil-filled heater came on in a cool room, it cycled on and off on cycle lasted less than 5 min. then off period of about 30 min.). I moved the heater to a warm room with the same setting, it cycled on and off in the same manner. It appears to cycle on and off regardless of the temperature of the room. Middle dial set at III, little lever in the lower red dial set to "--".