We have a heat pump and a Rogers White 1F89-211 thermostat. Before we left on vacation for 10 days, I set the air conditioning on 78 degrees because wasn't concerned with the house freezing... more concerned that we would have a really warm day and didn't want the house to get below 78 degrees. When we got back, the temp in the house was 78 degrees and the fan was on. I immediately switched the thermostat to off and it would not go off. Then I shut off the breakers to the system and the air handler and opened the doors to cool the house off. Since then, we've turned the system on for short periods to keep the house above 70 degrees but still can't get the system to turn off at the thermostat. The system is definitely heating but doesn't appear to be cooling, but the air handler fan runs all the time.