Why Air Conditioners Freeze Up

Why Air Conditioners Freeze Up - AC Unit in Back of House.


Did you accidentally stumble upon your air conditioning (AC) unit’s “winter weather” setting? Nope. You’re probably experiencing a freeze-up.

Did you accidentally stumble upon your air conditioning (AC) unit’s “winter weather” setting? Nope. You’re probably experiencing a freeze-up.

If you’ve noticed a thin layer of ice on the outside of your AC unit, don’t panic. Freeze-ups are an incredibly common issue. Most central air systems will experience one at some point. 

Remember that prevention is the best cure! Routine maintenance visits allow one of our A & L Heating and Air specialists to check for hidden issues that could lead to freeze-ups. It also helps your equipment to run more efficiently, saving you money on utilities.

Even basic restorative tasks like replacing a clogged filter can slash up to 15 percent off your energy bill, according to the US Department of Energy (DOE). Schedule your AC visit now so you can beat the Tennessee summer heat without interruption. 

Why Air Conditioners Freeze Up

Freeze-ups happen when moisture forms on your air conditioner, which converts it to frost. Here are a few common ways this can happen: 

Refrigerant Leaks

The refrigerant liquid circulates through your air conditioner’s evaporator coils. It’s the “special sauce” that helps the machinery pull humidity from the air, so your Maryville home gets cool. If a coil gets cracked or punctured, your AC becomes compromised. 

Moisture in the air builds up and coats the coils, turning to an icy film. You may also notice patchy air cooling or no cold air at all. Sometimes, a chemical smell will be present. 

If you suspect a refrigerant leak, call one of our heating, ventilation, and air conditioning (HVAC) professionals. Your technician will identify and patch the leak, then restore proper refrigerant levels. 

Poor Airflow

If liquid levels aren’t low, check the airflow. Sometimes, your evaporator coil freezes because something is preventing proper air circulation. The most frequent culprit is a dirty air filter. That’s why it’s best to replace or clean your air filter once monthly. 

Alternatively, it can happen when objects block your vents or fall into your ductwork. Broken fans and dirty coils could just as easily be to blame. 

Mild Outdoor Temperatures

Sometimes, the weather can get cold overnight when you’re asleep. These sudden temperature drops can throw your AC for a loop. The cool air from outdoors lowers the pressure, which can make your unit freeze up.

Remember to turn your air conditioner off well before the onset of cool weather. Most AC units can’t handle temperatures below 60 degrees Fahrenheit.

What Should I Do If My AC Freezes?

  1. Switch your air conditioner off. 

This will allow the ice formations to melt. Additionally, any mechanical issues going on are less likely to progress.

2. Check for obstructions.

You want all of your air vents to have enough breathing room. Be sure there isn’t a misplaced couch or carpet getting in the way.

3. Inspect your air filter. 

If your filter is dirty, it’s a quick fix. Simply replace or clean it (if the filter is reusable). Now try turning your AC back on once the ice has melted and dried up. 

4. Call your HVAC specialist if the problem persists.

If the filter and vents are fine, the problem may be slightly more sophisticated. Have one of our HVAC specialists diagnose and repair it.

Need prompt and professional AC repair?

A & L Heating and Air is ready to assist you with your Maryville, Tennessee heating and cooling needs. Call our office at 865-856-8797 or request service online.

Need HVAC Service?

Contact the experts at A & L Heating and Air.

Call us at 865-856-8797!

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