Why would a heat pump freeze up in the winter?

Heat pumps can sometimes ice up during cold weather and here is an explanation as to why. A heat pump works by using a refrigerant that absorbs the heat energy from the surrounding air. As the air passes across the evaporator and the heat energy is extracted, this will cause the water vapor in the air to cool and condense onto the evaporator. In winter temperatures this condensation can freeze which is perfectly normal.

If this frozen condensation is allowed to build up, this will impact the heat pump’s ability to operate correctly, either reducing its performance and overall efficiency or preventing the unit from working at all. It is therefore important that heat pumps are designed to work successfully in cold outdoor temperatures by incorporating a mechanism that prevents excessive build up of frozen condensation.

Grant heat pumps are designed not to freeze in the Winter

As you have invested in a Grant air source heat pump, you can be confident that it will still work throughout the cold winter months. This is because your Aerona³ heat pump has a built-in defrost function which ensures the evaporator is kept free of any ice buildup, enabling your heat pump system to continue to work during cold weather. Your heat pump also features a heating element in the base of the unit which will automatically operate when the outside air temperatures fall to 2.5°C or below – this heating element helps prevent the formation of ice in the base of your heat pump. Find out more about the defrost function mode and how it stops your heat pump from freezing in the winter.

What should you do if your heat pump freezes

up?

In the unlikely event that the defrost cycle on your heat pump fails to operate and/or an issue arises which prevents the automatic heating element from working, it is possible that your heat pump will freeze up with condensation if the outside temperatures are very low. In such cases, a fault code should appear on your heat pump controller’s display screen and it is recommended that you speak to your heating engineer for support. Please do not attempt to thaw any frozen condensate by pouring boiling water on your heat pump as you will likely damage the unit.

You can learn more about looking after your Grant air source heat pump and some of its features by watching the video below – the section about the defrost cycle and heating element starts 43 seconds into the video.

The information provided here is advice only - if you are not happy to check your product, please contact a heating engineer to assist.

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