Expert advice on how to fix heat pump problems, such as heating or cooling poorly and more. Includes step-by-step DIY advice.

Heat pump problems are often caused by thermostat malfunctions. To test your thermostat and fix any problems, see Thermostat Repairs. If your home is heated by a furnace instead of a heat pump, please see Furnace Troubleshooting & Repairs.

A black Lennox high efficiency heat pump.


If your heat pump does not heat or cool properly, freezes up, or cycles off and on too frequently, this article will help.

Following is step-by-step advice for troubleshooting typical heat pump problems and DIY heat pump repairs.

Here we will deal with heat pump power problems; a heat pump that freezes up; improper heating, cooling, and cycling by a heat pump; blower issues; heat pump noises; and more. If these simple repair techniques don’t work, have a heat pump repair technician (go to HomeAdvisor) check out your system.

If your heat pump needs to be restarted at low temperatures, check your owner’s manual for proper techniques. If you can’t find your owner’s manual, try searching the make and model online for a free PDF manual. For models with a system selector switch, turn the switch to Emergency Heat and wait six hours. Then return the switch to the normal setting.

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If the heat doesn’t come on even when the thermostat is set above room temperature, the problem is usually that it isn’t receiving power because of a tripped circuit breaker or blown fuse.

Note: If the weather is particularly cold and your heat pump doesn’t seem to be working right, please see Heat Pump Cold Weather Problems.


Heat Pump Does Not Run

If your heat pump doesn’t go on at all, there is a problem with the thermostat or the unit isn’t receiving power. Do the following:

1 Be sure the thermostat is set to the proper setting (“Heat” if you’re calling for heat) and the temperature you want the room to be. If the thermostat was replaced recently, the new thermostat may be the wrong type—it must be specifically a heat pump thermostat. Or, it may have been wired improperly. An improperly wired thermostat can fry electronic components, preventing the heat pump from working properly.

2 Be sure the heat pump is receiving power. The two circuit breakers that protect the electrical circuits providing power to the air handler and heat pump condenser may have tripped.

Man’s fingers holding a red circuit breaker switch including an arrow pointing to a direction.
Turn the circuit breaker all of the way off, then flip it back to “ON.” © HomeTips

Check both the main electrical panel and any electric subpanels that supply power to the unit. If a circuit breaker has tripped, reset it by flipping it to OFF and then to ON.

If the circuit breaker trips again, there is probably a short in the electrical system that normally provides power to the furnace. Call an electrical contractor (go to HomeAdvisor).

3 If the heat pump is connected to a power switch, either on the wall near the unit or inside the air handler cabinet (many don’t have switches), be sure the switch is turned on. If it is turned off, turn it on and wait a few minutes for the air handler to engage.

4 If your heat pump has electrical elements that provide supplemental heat as most do, the circuit breakers or fuses that protect the heating elements may have tripped or blown. They are usually located inside the air handler cabinet. Reset them.

HomeTips Pro Tip: Opening up the cabinet of a heat pump and working with electrical parts can be dangerous for the inexperienced. If you don’t have the necessary knowledge and skills, call a heating repair technician (HomeAdvisor).

Heat Pump Doesn’t Heat or Cool Right

Heat pumps don’t discharge air that is as hot as the air discharged by oil or gas forced-air furnaces, so don’t expect their output to feel like that of a furnace when they’re on.

But if you’re used to a certain temperature of air and your heat pump is producing much cooler air, take the following steps.

Please note: A heat pump may go into a defrost mode to prevent icing up. When this happens, it can temporarily output cold air. Also be aware that the heat pump will have to work harder to produce heat when in defrost mode and/or when it’s particularly cold outside.

1 Be sure the thermostat is set properly. Raise the set temperature 5 degrees F. and then wait a few minutes for the heat to come on.

2 Be sure the room-heating registers are open.

3 Check the heat pump filter. If it is dirty, change it as described in the article How to Replace a Heat Pump Filter.

A hand placing a new air filter in a wall register, with airflow arrows pointing toward the ductwork.
Twice a year, change all filters—including the return-air filters like this one. ©Don Vandervort, HomeTips

4 Be sure the auxiliary heating elements are working (if your heat pump has these).

5 Clean the coils of the outdoor condensing unit (see Central Air Conditioner Repairs).

6 If these simple steps don’t work, have a heat pump repair technician check out your system. Either the blower isn’t working properly or the system is out of balance in some other way. For example, the reversing valve may be stuck in the wrong position.

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About Don Vandervort
Don Vandervort has developed his expertise for more than 30 years as a remodeler and builder, Building Editor for Sunset Books, Senior Editor at Home Magazine, author of more than 30 home improvement books, and writer of countless magazine articles. He appeared for 3 seasons on HGTV’s “The Fix,” and served as MSN’s home expert for several years. Don founded HomeTips in 1996. Read more about Don Vandervort