Many homeowners with newly installed heat pumps might be alarmed when they notice on a cold day that the outdoor part of their heating system appears to have frozen over. Don’t panic, because this is completely normal! However, there are some instances in which a frozen heat pump could indicate a problem with your unit. So let’s take a look at why your heat pump freezes over and what you can do to prevent it from happening when it shouldn’t.

Why does a heat pump freeze up during winter?

If you read our blog about how a heat pump works, you’ll know that heat pumps use refrigerant to absorb heat from the air outside – even when it’s cold out. As heat from the air outside is transferred to that refrigerant, some excess moisture from the air builds up on your unit’s coils. On cold days, that moisture can freeze into layers on your heat pump, making it difficult for your unit to perform properly.

How does a heat pump protect itself from freezing?

Luckily, your heat pump is designed to handle the buildup of ice that we described above. You see, your heat pump has a defrost cycle that kicks on when it detects excessive ice buildup. While in the defrost mode, your heat pump essentially operates in the cooling mode and allows heat from the refrigerant to melt the ice away. As this is happening, a backup heating cycle keeps your home warm until the ice has melted away and the heat pump is ready to operate as normal again. It should be noted that if your heat pump is still frozen after 30 minutes in the defrost cycle, you should contact Jerry Kelly Heating & Air Conditioning.

How can you help protect your heat pump from freezing?

One of the primary reasons why your heat pump might freeze over when it normally shouldn’t is a lack of proper airflow. To prevent this from happening, you can:

  • Check, clean or change your filter every month
  • Remove any ice that has built upon the top of your outdoor unit (use a garden hose to melt the ice away instead of jabbing it with a sharp object, which might bend the fins underneath)
  • Clear away any excess snow or debris that has built up around your outdoor unit

If you have any questions about a heat pump freezing during winter, or if you’d like an HVAC system serviced or installed in your home, contact Jerry Kelly Heating & Air Conditioning heating and air conditioning. We service the St. Louis area and surrounding towns like Manchester, St. Paul, and Clayton, MO.

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