Check that the thermostat is set a few degrees higher than the room temperature if the heat pump is not heating the room sufficiently.
Move the fan switch from "Auto" to "On" to test for power to the air handler. If the blower engages, the unit is operating properly. Check the circuit breakers on the air handler cabinet if the blower does not turn on. Inspect the breakers and fuses in the household electrical panel. Reset breakers that have tripped by flipping them off and then on again. Replace blown fuses. If the breakers continue to trip, call a qualified Tempstar service technician to investigate further.
Verify that the condenser is running if the heat pump runs constantly but the unit does not produce the desired heat. Check to see if the high-pressure cut-off switch has engaged. The high-pressure cut-off switch is a button protruding from the cabinet in the area of the refrigerant pipes. Press on the switch. If the unit starts up, the head pressure may have gotten too high. If the cut-off switch continues to trip, have a service technician check out the unit.
Check the air filter if the heat pump runs continuously on a moderately cold day. The heat pump is expected to run continuously on an excessively cold day, as it does not put out the same amount of heat as a fossil fuel furnace. Knock the air filter against the palm of your hand to clear away debris. Use a vacuum if the filter is excessively clogged. Vacuum around the area where the air filter sits. A dirty air filter can interrupt air flow.
Switch the heat pump over to the auxiliary stage for a couple of hours if the pump tends to freeze on cold, humid days. The heat pump has two stages, and the secondary heat source is electric or auxiliary. This will turn off the heat pump and allow it to work through a number of defrost cycles.