If you use a heat pump for heating and cooling in your Wilmington, DE home, you may be familiar with occasional frost on the outdoor condenser coil. A little bit of frost is normal. But when you check the outdoor section of your heat pump and see it encased in ice, that’s cause for alarm. What do you do when you find your heat pump has iced over?

What Causes Heat Pump Frost?

As heat from outside air is absorbed by the refrigerant in a heat pump, excess moisture in the form of condensation can occur on the coil. When it’s cold outside, that moisture can freeze in layers.

The heat pump has a defrost cycle that kicks on when frost appears, and goes into cooling mode, with heat from the refrigerant melting the ice. While this is happening, the heat pump uses backup heating to keep the home warm until the ice is melted. Normally the defrost cycle is finished within 30 minutes. If it isn’t, you will want to correct whatever’s causing severe icing as quickly as possible, especially if your heat pump is using costly electric resistance heating as backup heat.

What Causes Heat Pump Icing?

The following are things you can do to prevent icing:

  • Check to ensure the coil is free of debris, ice and snow. Remove ice with a garden hose.
  • Leaking rain gutters or freezing rain may cause icing. Protect the unit from these conditions.
  • If the unit sinks into the ground, water may pond around it and result in ice. The unit will have to be raised.

The following tasks should be performed by your service expert:

  • Test the refrigerant charge. Improper refrigerant charge can cause icing.
  • Check the reverse or relay switch to make sure it’s not faulty.
  • Check the fan motor.
  • Check the defrost thermostat or sensor.

To learn more about what to do when a heat pump has iced over, contact us at William G Day Company today!

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