Is your Heat pump freezing up?

Several years ago I was sitting at my desk on a bitterly cold weekend morning and realized that the house wasn’t as warm as it usually was and that the heat pump outside my window sounded louder than normal. Imagine my surprise (and horror) when I looked outside and saw my heat pump had about 8-9 inches of solid ice built up on the top. It was pretty clear that I had a major problem. My Husband was traveling so no calling for “Honey.” Even with my limited knowledge of how the heat pump should work, I knew that the layer of ice on my unit was an issue that couldn’t wait. A call to ADA Heating and Air was even better than calling “Honey.”

What is Normal in Winter

The certified technician from ADA explained that it was normal for a little frost to build up on the unit in the winter. A heat pump transfers heat by drawing in natural heat from the outside air or ground and compressing it. Then, with the use of refrigerants, the heat is converted into gas and transferred to a coil inside the house. The action of the refrigerant can release condensation that will form a frost layer. In a properly functioning unit, a defrost cycle will initiate automatically whenever frost forms.

Incased in Ice

The technician didn’t need to explain that “incased in ice” was not normal. There are multiple reasons why a heat pump can freeze. Most of the issues that can cause freezing would have been caught on a seasonal inspection of the unit if there had been a maintenance contract in place. Some common causes of heat pump freezing are;

  • Refrigerant levels are inadequate
  • Defrost sensor, thermostat or relay is faulty
  • Fan motor has failed
  • Unit not receiving air circulation due to build-up of leaves, weeds or debris
  • Unit not receiving air circulation due to build-up of snow
  • Unit not supported by platform allowing it to sink into the ground
  • Gutter above unit has developed a leak allowing water to drip onto the unit
  • Freezing rain

Heat Pump Freezing: Your Options

If you find your heat pump incased in ice, you may be able to solve the issue without a service call, depending on the reason why the unit has iced over. Take the following steps;

  • Turn off the unit to allow ice to melt and to prevent further damage
  • Turn the unit onto emergency heat
  • Remove and accumulation of snow, leaves, or debris from around the unit that may be blocking circulation
  • If faulty gutter exists, repair the gutter
  • Gently chip away the ice from the coils. Never use a sharp object to break up ice as the refrigerant coils and blower fan blades can be damaged easily.

Many of the causes of heat pump freezing are not DIY. If you have taken the steps above and the unit remains frozen, or if the steps above only solved the problem temporarily, place a call to your service technician.

ADA Heating and Air will send a NATE Certified technician (North American Technician Excellence) to perform diagnostics on your unit, make recommendations on repair, and provide a written estimate. My unit had two problems that had resulted in a frozen unit; low refrigerant levels and a unit that had not been properly footed. A seasonal maintenance contract would have caught both issues and an after hours service call would not have been necessary.


ADA Heating and Air is a family owned firm that has been servicing Danville, Nicholasville, Versailles, Winchester, Harrodsburg, Stanford, Lexington and the surrounding Central Kentucky areas for over 20 years. They are trained to service or repair all makes and models. Call today for your emergency repair or to avoid a crisis like mine by initiating a seasonal maintenance program.


By | 2017-08-02T01:20:32+00:00 January 26th, 2017|Heating|Comments Off on Is Your Heat Pump Freezing Up?

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