Knowing how to troubleshoot a heat pump thermostat can save money as well as frustration. There are many things that could cause the heat pump to not work properly. Checking the thermostat is a good place to start. If a problem is in the thermostat and not the heat pump, a call to the repairman may not be necessary.
Remove the thermostat cover by unsnapping it from the thermostat housing by hand.
Locate the heat anticipator, which is in the center of the thermostat. It is a small disc with numbers and probably the word "longer" on it. If the temperature is not reaching the set temperature, move the dial with your finger one calibration mark away from "longer."
Replace the thermostat cover and check the operation in a couple of hours.
Turn off the power to the heat pump at the circuit breaker box.
Remove the cover from the thermostat.
Gently clean the contact points on the thermostat with a cotton swab and rubbing alcohol.
Inspect and tighten any loose wire terminal connections using a small Phillips head screwdriver.
If the thermostat is a digital model, check to see if the battery is good. An indicator light will be on the thermostat.
Replace the thermostat cover and set the desired temperature. Turn the power back on to the heat pump at the circuit breaker box.