I've had one for about a year. It has worked ever since I plugged it in. I runs continuosly though, I don't know if my humidor isn't sealed well or that's just what it does. It has two modes, the constant humidification and the extra fan that is supposed to activate when you open the door. Both fans run most of the time. I have messed with the adjustment knob as well but it doesn't seem to make a difference.