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Wondering Why Your Heat Pump’s Gone Frosty? Maybe We Can Help


frosty heat pump. Under most circumstances, it’s natural for a coat of frost to cover some of the heat pump’s outdoor condensing coil.

A heat pump doesn’t create heat. In the heating mode, it gathers heat from the air outside and brings it indoors via the refrigerant. When the outdoor component freezes in the winter, it indicates there’s enough humidity in the air for frost to form. Should the coil be colder than the dew point of the air, frost builds.

The dew point is the temperature at which humidity condenses into water. The relationship between temperature and humidity dictates the dew point. As a rule, colder air can hold less humidity, so you may see more frost form when temperatures are relatively mild for winter and conditions are damp.

Heat pumps will go into a defrost cycle that involves reversing the flow of refrigerant, taking heat from your home’s air to warm the outdoor condensing coil to melt the frosty heat pump. You may notice your home is cooler briefly or that the electric heating coil inside the pump turns on for supplemental heating during the defrost cycle.

You can avoid some of the frost buildup by starting the heating season with a clean outdoor condensing coil that has free air circulation on all sides. A clean condenser will prevent some of the frost buildup and keep energy bills lower.

If you notice that the frost doesn’t melt away reasonably quickly from the heat pump’s condenser, you may need to seek professional assistance. It can signal a problem with the condenser’s outdoor placement or position, improper refrigerant level or other mechanical issues that need to be fixed. It may also mean that you have water draining on the condenser or too much snow building on top of it or around it.

To learn more about avoiding a frosty heat pump, contact HAVC Unlimited Heating & Cooling. We provide trusted HVAC services for homeowners in Prince William, Loudoun and Fairfax counties.

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