MATTSDAD66
Apr 1, 2014, 12:20 PM
The screen on the programmable thermostat went blank when I switched from heat to cool with the mode button. I have 27 volts dc out of the transformer and only 13.5 volts dc at the thermostat. The led light blinks two times and then three times and then repeats itself. I have checked the pressure switch and it is clear.