How to Keep Your Air Conditioner From Freezing

We all count on our HVAC system to keep us cool during the heat of the summer. There’s nothing more disappointing than realizing that the A/C we count on has frozen up.

A frozen air conditioner is a symptom of a couple of different problems. The most common cause is an air flow block, often caused by a dirty filter.

When your air conditioner is working as it should, air flows over the evaporator coils and dries up whatever moisture has collected there from the difference in the coolant-chilled components and the warmer surrounding air. When something keeps the air from flowing fast enough, that condensation collects and freezes.

Luckily, there’s a simple way to figure out if your frozen air conditioner was caused by a dirty air filter. As a bonus, you’ll be fixing the problem at the same time. Just follow these simple steps:

Completely shut your A/C off. It will begin to defrost once it’s no longer pumping refrigerant through the lines.
Clean or replace your air filter.
Leave the A/C off but run the fan. Give it at least 60-90 minutes before you try the A/C again.

Once everything has defrosted, keep an eye on the system to make sure it doesn’t freeze up again. In many cases, changing the filter will solve the problem. Just remember to keep replacing or cleaning your filter every 30–90 days to keep your A/C from freezing up again.

If your frozen air conditioner wasn’t solved by changing the filter, you may have a bigger issue: a refrigerant leak. To locate a leak, you’ll have to call a service technician. Once the technician has located the leak, there are two possible outcomes:

If your HVAC system is reasonably new and otherwise in good shape, the leak can be fixed and the refrigerant topped off.
If your system is older and/or has other problems in addition to the leak, you may need to look into replacing it.

For more expert HVAC tips on preventing a frozen air conditioner and more, contact Roth Home & Cooling. We’re proud to serve the Portland area.