The fans in the outdoor unit must also run in order to draw the outside air across the coils where the refrigerant absorbs its heat through evaporation and then takes it indoors. Nonetheless, you should stay vigilant when it comes to the sounds your heat pump makes while it operates.

Ideal Winter Heat Pump Temperature Settings According to the Department of Energy, 68°F is the sweet spot that balances comfort and energy efficiency during the fall and winter months. When your home is occupied and when family members are awake, a heat pump setting of 68°F keeps the living areas reasonably warm.

If your heat pump won’t turn off, switch the thermostat setting to “Heat Off.” If your thermostat doesn’t have a switch, try setting the thermostat above the current room temperature. This should turn the heat pump off temporarily.

It doesn’t happen all that often, but it’s a fact of life when you’re trying to extract heat from cold, outdoor air. Sometimes the outdoor coil goes below the dew point, and frost results. There’s nothing wrong with that. Every heat pump comes with a built-in defrost system so it will keep running smoothly.

5-15 minutes

#1 Solution: Give the System Some Time If your heat pump doesn’t seem to be running, just give it 3-4 hours to defrost itself. This will almost always solve the issue and your system will kick back in and continue heating without any noticeable temperature drop within your home.

How do I know it’s working?

1. If the outdoor temperatures have been freezing for some time, expect the heat pump defrost cycle to begin.
2. The unit will cease blowing warm air into your home during defrosting which may cause you to hear a humming sound.
3. The defrost cycle typically lasts about 10 minutes.

You can pour warm water over the unit to melt the snow and ice. Even cold water from a hose will help. Don’t use any sharp objects to pick or knock the ice off the coils of the heat pump. If the unit ices up again, call for service.

Checking the Defrost Sensor

1. Remove power from the condenser.
2. Find and remove the defrost sensor from the condenser and unplug it from the control board.
3. Place the sensor in a container of ice water and using your multimeter, ohm across the terminals, the sensor should read zero ohms (closed).

Worn or damaged defrost control boards: $150-$600. If your unit is “icing up” with increasing frequency, you may have a faulty defrost control board. Faulty timer motors: $200-$250. Older model heat pumps contain timer motors that control the defrost mechanism.

Usual design: a control circuit board in the outdoor compressor/condenser unit controls the defrost cycle timing and length. The heat pump switches from “heating mode” back to “cooling mode” in order to warm the outdoor coil and thus melt frost or ice thereon.

The defrost thermostat should be in the closed position when cold. Check to be sure the thermostat is opening at the correct temperature by placing it in water and slowly heating the water. Defrost thermostats are designed to open between 40 degrees and 90 degrees Fahrenheit.