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What Causes an Air Conditioner to Freeze Up?

Summer is here, and you’re counting on your AC to keep things chill. But what’s worse than a heatwave? An AC that’s turned itself into an ice machine. The team from Primo Heat knows a thing or two about frosty AC problems. Let’s break down the cold hard facts of what causes an air conditioner to freeze up and answer some basic questions to help you determine the state of your AC.

what causes air conditioners to freeze up

1. Lack of Air Flow

Your AC needs a steady flow of air to keep it cool. When air filters get dirty or clogged, the airflow decreases. Guess what? Less air flowing through the AC means the coils can freeze. To avoid this, make sure you’re changing or cleaning those filters regularly. Just like you need air, so does your AC.

Here’s an AC maintenance checklist to help you along the way.

2. Low Refrigerant

Freon, or the refrigerant, is the juice that cools the air. But if there’s not enough of it, the pressure drops and the system can’t absorb enough heat. That leads to—you guessed it—freezing. It’s essential to keep an eye on refrigerant levels and make sure there are no leaks. If you suspect your system is low on refrigerant, it’s time to call our pros.

3. Dirty Evaporator Coil

If the evaporator coil looks like it went mud wrestling, you’re in for trouble. Dirt and debris insulate the coil, stopping it from absorbing heat properly. If it’s not taking in heat, it’s going to freeze. Clean coils are happy coils, so make sure they’re not dirty.

Learn all about the benefits of servicing your AC regularly.

4. Thermostat Issues

Setting your thermostat too low can cause the system to work overtime. When it can’t keep up, you can find yourself with ice building up on the coils. Keep your thermostat set at a reasonable temp. The pros at Primo Heat recommend permanently holding a set temperature for the duration of cooling season to avoid overworking the system.

5. Fan Issues

If your AC fans aren’t running right, there is not enough air moving over the coils. Without enough air movement, the coils get too cold, and—boom!—freezing happens. Make sure the fans are in tip-top shape and, if they’re not, it might be time for replacement.

6. Drain Line Check

The AC removes moisture from the air, which typically drains away. But if the drain line is clogged, water can’t escape and ends up freezing on the coils. Keep those drain lines clear for a optimally functioning AC.

7. Air Duct Blockage

Sometimes, the problem is a bit deeper in the ducts. If your air ducts are blocked or leaking, the airflow to/from the AC gets restricted. This is another airflow issue that can lead to freezing. Regular maintenance is key!

Remember, if things get too frosty, the team at Primo Heat is here for all your HVAC needs. So don’t hesitate to reach out via our website form to set up a diagnostic appointment if things are too frosty!

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Fraser Valley’s Leading HVAC Specialists & Lennox Dealer