Put in a Honeywell thermostat from Home Depot and last week it was fine. The AC worked, the furnace kicked on and all was right in the world.
Today I turned on the furnace and it came on BUT the AC also came on??? I don't know why it would do that now. I let it run for a few minutes and they both stayed on.
It did not do this last week and I have done nothing since to the thermostat or the wiring.
1994 Tioga with a Coleman AC on roof.
Would like to figure this out before our trip on Friday as we may need heat up in Northern VT.