My controller also turns on and off fridge (or plugged in heating pad) and/or humidifier or dehumidifier, it is not a unit just for humidity. It is supposed to control one or the other, but not both at the same time. Maybe that is where it will fail. The question and answer section of Amazon made it sound like if the controller shuts off power to dehumidifier, once it powers back up, it will not come back on. It has no problem turning on humidifier and turning it off. It is to be here tomorrow, 3 days early, so I will get to see. Do you have any kind of special dehumidifier? Or is it simply an on/off switch?