My thermostat went blank yesterday, was running as normal and suddenly went blank, won't turn on and I don't know what to do. My ac unit has gone out in the past once but thermostat continued working even while ac unit was down, have no idea what happened yesterday but hoping someone can give me an idea of where to go from here. Thx:confused:

Does it take battries?

Usually the result of power to thermostat being lost. If this is an older version (two-tone brown/tan), remove the thermostat from the switching base and check the interface terminals (pins on base, copper strips on thermostat) for oxidation.