How to Troubleshoot a Malfunctioning Heat Pump

A heat pump mounted beside an air conditioner unit.
  • 1-2 hours
  • Beginner
  • 15-50
What You'll Need
Air filters
Low pressure hose
New batteries
What You'll Need
Air filters
Low pressure hose
New batteries

Heat pumps are a cost-effective alternative to central air in moderate climates. Through transferring hot air in and out of your home, it regulates your temperature to the desired level. However, if you're starting to have problems with functionality when summer rolls around, it can quickly become very uncomfortable inside. Try these simple troubleshooting techniques to get your heat pump back in proper working order.

Step 1 - Check Your Settings

This simplest possible solution is always the best to try first. If your heat pump worked fine when it was chilly but is failing you now that warmer days have arrived, check that the thermostat is turned to cooling and set on automatic. These switches are generally located on the side or bottom of the unit.

If this doesn't solve the problem, try turning the machine to “fan only,” to make sure that your fan is running properly. Be sure to keep the thermostat at a temperature setting that is comfortable for you; if the setting isn't low enough, the heat pump won't kick on.

Step 2 - Check Your Filter and Clean Debris

Your filters have to be clean in order for your heat pump to work correctly. You should change them monthly during heavy use seasons. If the filters are clogged or there is debris around your compressor, that can explain the cooling problem. Use a low pressure hose to wash away caked on dust and debris, and then try having your heat pump run to see if the issue is resolved.

Step 3 - Change the Batteries on Your Thermostat

Electronic thermostats often need frequent battery changes. Try inserting a new set to see if it improves the functionality of your heat pump.

Step 4 - Defrost the Heat Pump

Heavy ice buildup on your unit can also cause malfunctions. Sometimes the energy efficiency settings will prevent the defroster from working long enough or often enough to keep your unit clear. To fix this, try running the “fan only” setting for an hour or so to melt the ice. If this is a recurring problem, consider moving the outdoor sensor to a more ideal location, closer to the coil's outtake.

Step 5 - Check Your Power Source

Check your fuse or breaker box to make sure that the heat pump is receiving power. If the heat pump starts and stops, or continuously flips the breaker, you may have either a problem with the compressor or a problem with your home's electrical wiring. At this point, it is advisable to have an electrician come out and take a look at the problem.

Step 6 - Add Refrigerant

Low refrigerant levels can limit the functionality of your heat pump, or even cause it to fail. However, adding refrigerant requires a special license, because handling the materials is extremely hazardous for those without specific experience and training. The EPA has specific guidelines for the disposal of refrigerant, which is harmful to both humans and wildlife. So, if you are in need of refrigerant, it's time you called in a professional.