Maintaining your heat pump

Outdoor Ductless Heat Pump Unit

Do you know what kind of heating system you have? It’s OK if you don’t—this question catches many people off guard. This shouldn’t, however, be an excuse for not maintaining that system!

If you have an outdoor unit, it is either part of your air conditioner, or means that you are heating and cooling your home with a heat pump.  There are two types of heat pumps—ducted and ductless. If you have registers that supply heat in each room, you have a ducted system. You  will usually find your air handler in your garage or basement with large ducting coming off of the system that moves the conditioned air through your home.  If you have a unit mounted on your wall, commonly called a distribution head, you have a ductless system. Often times you will have a couple of centrally located heads with your ductless system.

 Heat pumps are one of the most energy efficient ways to heat your home, but like all heating systems, proper maintenance is crucial to efficient operation. Your heat pump can be 10 – 25% less efficient when neglected.

First things first–before you get started, turn off the power to the system. You can either turn the system off, or for higher safety, turn off the circuit breaker at your electrical panel.


  • Keep the outdoor unit clean and clear of debris. Remove leaves, grass, weeds and other debris away
    from the unit. You can spray the unit down with a hose to be sure that you are removing all debris. The compressor may overheat causing damage to the system if not cleaned regularly.

Outdoor Heat Pump Unit

  • Using a rag and warm water, wipe the outside of the unit, wiping dirt and dust from the vents as well. You can use a garden hose to gently spray down the fan and coils.
  • Check the system monthly to ensure that the unit is draining properly. Remove any clogs as necessary. During the cooling season, you should be able to see water trickle from the outdoor condenser unit.


  • For ducted heat pump systems, it is a good rule of thumb to check the filters in your air handler once per month or every three months at the minimum. The more people and pets in your home, the more often you should be changing your filter.
    • Turn off the power supply to your heat pump.
    • Locate your filter in your air handler unit. It is usually located at the juncture of where the air handler meets the ductwork.
    • If your filter is disposable, find your filter size which will be listed on the filter frame and replace it with the same size filter. You will know if your filters is disposable if it has a cardboard frame.
    • If your filter is reusable, wash in cold water with a mild detergent. The filter must be completely dry before reinstalling.
  • For ductless heat pumps, it is a good rule of thumb to check the indoor air handlers’ filters once per month or every three months at the minimum. The more people and pets in your home, the more often you should be cleaning your filter.
  • Ductless heat pump filter
    • Turn off the power to your heat pump.
    • Removing the filter is easy—look for arrows on the surface panels for directions on how to remove the panels and reveal the filters inside.
    • You can use a vacuum cleaner for lighter dust and can gently wash for stickier debris. Lukewarm soapy water should work well and if there is buildup, you can soak the filter for as long as necessary. Let it air dry then reinstall.

It is best to have your system checked annually by a technician. You can find a list of professionals from the Energy Trust of Oregon here.

Photo Credits: GreenSavers, Certified Home Performance Contractor