JanAndBill
Well-known member
Today for the first time in a couple of months we kicked on the main A/C while we went to eat. When we came back I was going to change back over to heat, and I noticed the LCD was flashing E4. Looked it up in the book and found this - "E4 Open circuit or out of range Outdoor Temperature Sensor (select models). Heat pump and dehumidification operation will be locked out. Air conditioner, furnace, heat strip and fan operation can continue to operate." I don't have a heat pump. Pulled the 12 volt fuse on both the furnace and the A/C, nothing changed. When I flipped the 110 circuit breaker off, it reset. It's to cool now to see if the A/C works and not cool enough for the furnace to kick on. Any ideas if I have a problem that needs to be addressed futher???
