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Why My Air Conditioner Freezes and What to Do if it Does


The sizzling summer continues, and 4th of July is just around the corner. I want to celebrate the holiday with my very own hotdog, chilling and relaxing on my favorite vent spot. However, my plans almost didn’t happen! I had been noticing lately that our air conditioning was freezing up, thankfully my humans are cool air experts, and they fixed it in no time. Here is what I learned:

Why Air Conditioners Freeze Up

While there are many possible causes, there are three main things that freeze up your air conditioner:

  • Restricted Airflow
  • Low Levels of Refrigerant
  • Thermostat or Outside Temperature Issues

Let’s look at each one a little closer. Some of these can be fixed easily by yourself, and others will require calling my human experts.

Airflow Problems

This is the number one reason for a freezing air conditioner. When air goes too slowly through the cooling coil, moisture builds up and freezes. The first thing to o is check your air filters. A clogged up air filter will not allow air to pass through as fast. Got a clean filter? Next place to check is the ventilation. Are too many vents shut off, or do you see any obstructions? If so clear them out. If none of these are present, it’s time to call an expert.

Lost Refrigerant

The second most common cause for a freezing air conditioner is a loss of refrigerant. Well maintained systems shouldn’t leak. However, an ac system that has not been maintained can leak because of wear and tear.Refrigerant should not leak in well-maintained systems. The coil will freeze of the refrigerant leaks out of it. A way you can tell is if your electric bill rises. The air conditioner has to work harder to produce the same level of cold temperature. According to EPA guidelines, only a certified HVAC technician can replace refrigerant.

Thermostat and Temperature Issues

A faulty thermostat can also be the cause of air conditioner freezing up. A lot of the time this happens in cold weather months. A clear sign of a thermostat problem is the AC freezing only at night. Because it depends on warmer air, the cooling coil naturally freezes if the air around it is too cold. Your thermostat is supposed to turn off at the right temperature. If the AC continues to run, then this is also a sign of a problematic thermostat. This is more common with older models.

Call my people at MK Russell Heating and Air if your air conditioner is freezing up. They fixed ours in now time and I’m back at my favorite spot again.