Why is My Air Conditioner Freezing Up?

Protect your home A/C from Winnipeg’s summer heat by looking out for these common causes that require repair or maintenance to fix. Summer comes with no surprises every year, especially with our rise in humidity! It gets really, really hot. We crank the thermostat down and send our air conditioner into overdrive to try and keep us cool. Everything is great until the home air conditioning system freezes up. Home cooling systems and central air conditioners needing repair can ruin a hot summer real quick.

How does that even make sense? How can a unit freeze when it’s working around the clock in 30-degree weather? There are two fairly common reasons this happens to homeowners. And trust us, we see it every day. This is probably the most common issue our air conditioning contractors fix or provide maintenance for in Winnipeg.

A Winnipeg air conditioner with a frozen line

A dirty air filter like the one on the right is often the cause of a frozen air conditioner.
A clean furnace filter and a dirty furnace filter

1. Blocked air flow
The first potential cause of a frozen air conditioner is typically the air flow in your home. When your home’s air flow is restricted, there’s no air moving through the air conditioning system to keep the condensate on the coil from freezing. The culprit is usually a dirty air filter. This is a simple problem to prevent.

Best advice? Set reminders to regularly change your air filters, and get two A/C tune-ups each year to keep your system clean and efficient. Earlier in the season like April/May and September/October is better for maintenance, before HVAC contractors get busy with service calls.

If your air conditioner freezes up due to an air flow issue, switch it off to start the defrosting process. Next thing you should do is turn on the fan. Let it run for 60 to 90 minutes. Check and change your air filter during this time. After that, turn your air conditioner back to cool and it should start working again. Also make sure your coil is draining out of the supplied hose.

2. Refrigerant leaks
Then there’s the issue of refrigerant leaks. This is another common cause of your A/C freezing up. Whenever you’re leaking Freon or other coolant, it’s a decision point for homeowners. When you have a leak, it’s best to either get it fixed or invest in a new A/C, depending on the age of your current system.

Yes, you can get an HVAC company like Pyramid Heating and Air Conditioner to top off your coolant and get your system up and running again. However, it’s a temporary fix — and there’s no telling how long it will last. It could go a couple of months or a couple of weeks or a couple of hours before your A/C is frozen again.

If you suspect a leak, contact Pyramid Plumbing and Heating as soon as possible. Let a licensed journeyman technician pinpoint and repair the leak before it causes any other headaches.

Have you had problems with A/C freezing up? Tell us about it in the comments below.