The process of troubleshooting a heat pump depends on what the problem is. Some of the problems a user may encounter are that the heat pump doesn't run or doesn't cool or heat correctly, the machine freezes up or its blower doesn't work.
If the heat pump doesn’t run, make sure that the thermostat is set to the setting you need. If the thermostat is new, there is a possibility that it is not made for heat pumps orisn't wired correctly. Turn the circuit breaker off and back on. To make sure that the heat pump is receiving power, check the main electrical panel and all the subpanels that supply power to the machine. If a circuit breaker has tripped, reset it by turning it off and on again. If there is a power switch connected to the air pump, make sure that it is turned on.
To troubleshoot a heat pump that doesn’t heat or cool properly, make sure that the thermostat is set correctly, and raise the temperature by 5 degrees Fahrenheit. If that doesn't work, make sure that room-heating registers are open, check the filters in the heat pump and replace them if they are dirty. Make sure that the auxiliary heating elements are working properly, and clean the coils in the outdoor condensing unit.