7 Reasons Why Your AC Keeps Freezing Up | Blair's Air Conditioning

If you are like most people, you probably take your air conditioner for granted… until it starts acting up. If portions of your AC are freezing, know that sometimes, the issue can be easily resolved. However, it’s crucial to note that (a) you should always turn off the breaker that powers your air conditioner before you start working on it, and (b) some issues require an experienced technician to take care of them.

Let Google be your friend, but also know your limits. Becoming an HVAC technician requires certification for a reason.

7 Reasons Why AC Units Freeze Up

The evaporator coil is the part of your air conditioner that freezes up. It is responsible for transferring heat from the inside of your home to the outside.

There are several reasons your evaporator coil may freeze, learn 7 reasons why your air conditioner is freezing up below.

1. Dirty Air Filter

Your AC can also freeze up due to a dirty filter.

Your air conditioner’s air filter is in charge of catching air pollutants before they enter your home’s air ducts. Over time, these pollutants and allergens build up in your air filter, restricting the airflow.

Air conditioners absorb the warm air from your home, extracts the moisture, turns warm air into cool air, and blows it back out through your air vents. When the filters start restricting airflow, it becomes harder and harder for air to enter your home, and more importantly, your AC system.

As a result, condensation from the air’s humidity will start freezing over the AC coils instead of dripping into the drip pan.

The longer the filters remain dirty, the thicker the layer of ice becomes. Try replacing your air filters to help allow air to flow freely throughout your home.

2. Refrigerant Leak

If what’s freezing up are the side panels of the condenser unit (the outside portion of your AC), the reason could be a refrigerant leak.

If the refrigerant level is too low, then it will cause your evaporator coils to become too cold. Air that comes in contact with your evaporator coil will freeze.

Frost on the condenser unit is only one of the signs, however. If in addition to freezing, your air conditioner is making a hissing sound and the inside of your home feels humid, contact an HVAC technician ASAP, because extended exposure to refrigerant could result in refrigerant poisoning.

Call 727-592-8479 for AC Service in the Tampa Bay Area

3. Faulty Fan

Mechanical issues, such as a problem with your air conditioner’s fan, can restrict airflow and cause your air conditioner to freeze up.

The fan’s purpose is to help the cold air get to where it needs to go and to transport the warm air outside. If the fan is not working properly, the airflow will be disrupted, and too much condensation will build up on the coils. Just as with dirty air filters, the water droplets build up rapidly and start freezing on the coils.

4. It’s Too Cold Outside

Did you know you should not run your air conditioner if the temperature outside is less than 62 degrees Fahrenheit? This can cause pressure inside of the air conditioning system to drop.

If your home is too warm and it’s cold outside, simply open the windows.

Setting the thermostat to a temperature that is as low as the weather outside will cause the condensation from the AC to freeze. This is due to the fact that an AC unit needs to cool the air 18 to 20 degrees lower than the temperature you set on the thermostat in order cool your home to the desired temperature.

5. Dirty Air Ducts

Do you see a trend with all of these listed items? Anything that blocks airflow will end up causing a portion of your air conditioner to freeze up, and your air ducts are no exception.

Your air conditioner keeps your home cool by removing heat from it. If there is insufficient airflow, then this heat exchange cannot properly take place. This can cause your evaporator coils to freeze.

If you haven’t done this in a while, you may want to consider having your air ducts professionally cleaned.

6. Blocked Condensate Line

All this dripping water we keep mentioning is syphoned out of your home through a pipe that’s called a condensate line.

Even if everything else is working properly, with time, this damp pipe will gather sludge, and if not flushed regularly, will start growing mold inside.

Wait long enough and all of that nastiness may clog the condensate line. Since the water has nowhere else to go, it’ll start freezing on your coils.

You can prevent this from happening with a wet/dry shop vac and preventive AC maintenance.

7. Bent or Clogged Condenser Fins

The walls of the condenser unit are covered with metal fins that also have to be washed regularly to keep airflow moving optimally.

You can hose it down to keep dust and dirt away.

If you see that any of the fins are bent, place them back to their original position with a condenser fin comb.

Schedule AC Service With Blair’s Air

Dealing with an air conditioner that freezes up can be quite frustrating. That is why you should consider contacting Blair’s Air if your AC keeps freezing up. We will find the source of the problem and rectify it. We will also be able to take care of any of the other AC issues that you are having.

At Blair’s Air Conditioning and Heating, we provide installation, maintenance, and repair services for all of your HVAC needs. We also have a 24/7 emergency line for Pinellas County and South Tampa.

Call 727-592-8479 to schedule your appointment.