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What to Do When Your HVAC Unit Freezes in Winter

A frozen HVAC system in the middle of winter can be a costly and inconvenient problem in your home. The best way to prevent the problem is to have your system regularly serviced by a licensed professional. If you do find yourself with a frozen unit, the good news is there are some things you can do yourself to solve the problem before calling in a professional.

First Things First: Ice Is Not Always a Bad Sign

Ice or frost on your HVAC unit isn’t always a sign of a problem. When temperatures dip below freezing – which they do most winters around here – ice is par for the course. Moisture in the air condenses on your unit, then freezes in the cold air. Your HVAC unit is designed to deal with ice by running a periodic defrost cycle, heating the outside of the unit and melting any snow or ice that’s accumulated on it. But when there’s too much ice, frost, or snow built up on your unit, the defrost cycle can’t melt all of it, and it may affect your unit’s ability to function.

What Causes an HVAC Unit to Freeze Up?

There are a variety of things that could cause your HVAC system to freeze, and fortunately, most of them are preventable:

  • Restricted airflow can cause your unit to accumulate ice during the winter. Make sure to change your air filters regularly and have your ducts occasionally inspected by a professional to prevent airflow issues.
  • Do not allow snow, leaves, or other debris to build up around your HVAC unit, as they can also cause reduced airflow to the system.
  • A filter that prohibits adequate airflow is just as bad as a dirty air filter. Make sure the filters you use are the appropriate rating for your HVAC system.
  • Failed or malfunctioning parts can cause excess moisture to build up on your unit, which is then susceptible to freezing. This issue can be prevented with regular maintenance by an HVAC professional.

If you think your HVAC system might be frozen, you can check by following these steps:

  1. Turn off the system.
  2. Turn on the blower to thaw the evaporator coils.
  3. If you can feel warm air, your unit might be frozen.

How Can I Defrost My HVAC Unit?

  • If you have the ability to wait, switch off the fan, and your unit can thaw on its own. Note that this will take at least a few hours.
  • Run hot or even cool water from your garden hose over the unit to melt ice. Never try to chip away ice with anything sharp, as this could damage your equipment. Ensure that you remove as much water as possible after thawing, as leftover moisture can refreeze.

If these methods do not work, or if you encounter problems during the process, you should call a professional for assistance. Arronco Comfort Air offers a wide range of HVAC repair and heat pump services. If you need help preparing your system for winter or defrosting your HVAC unit, contact Arronco. We’re here whenever you need us.

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