I had a honeywell programmable thermostat and for some reason the unit outide stopped working but the one inside was OK. I didn't know what happened but for some reason when I slammed a door it vibrated the area of the wall where the thermostat is located and it started working. Every time I close the door next to the thermostat the wall always kind of vibrates. I opened up the thermostat to find the white wire connection burnt, but the wire was still good cause I switched the thermostat and it worked fine. I'm not buying the same brand thermostat.