What Causes AC to Freeze Up?

When your air conditioner starts icing over, it’s more than just an odd sight—it’s a sign something’s wrong. If not addressed, a frozen AC system can lead to poor performance, higher energy bills, and long-term damage. So, what causes your AC to freeze up? Let’s examine the most common reasons and how professional air conditioning services can help.

1. Restricted Airflow

One of the most common causes of a frozen AC is poor airflow. When air can’t move freely over the evaporator coils, their refrigerant gets too cold and forms ice. Dirty air filters, blocked vents, or blower fan issues can all restrict airflow. Regular air conditioning maintenance helps prevent this problem by keeping everything clean and operating efficiently.

2. Low Refrigerant Levels

Low refrigerant (often due to a leak) reduces pressure in your system and causes the evaporator coil to freeze. Low refrigerant might be the culprit if you notice ice buildup along with weak airflow or warm air. This issue requires professional AC repair to locate and fix the leak and recharge your system safely.

3. Thermostat or Sensor Issues

A faulty thermostat can overwork your system, leading to overly cold coils and potential freezing. Similarly, if a temperature sensor fails, your AC may not shut off when it should. Both of these can result in freezing. A trained technician can inspect these components during a routine air conditioning maintenance visit.

4. Drainage or Fan Problems

Your system produces condensation as it cools the air. Moisture can freeze on the coils if the drainage system is clogged or the fan isn’t running correctly. This buildup can lead to a complete system shutdown if left unaddressed. 

5. Aging or Improperly Sized Systems

Older units or improperly sized systems are more likely to develop operational issues like freezing. If your system isn’t meeting your cooling needs, a new air conditioning installation could offer improved comfort and energy efficiency.

Get Expert Help from Controlled Comfort

A frozen AC unit doesn’t fix itself. At Controlled Comfort, our skilled technicians are ready to help with fast, honest, and affordable air conditioning services. Whether you need emergency AC repair, regular air conditioning maintenance, or a complete air conditioning installation, we’ve got you covered.

Don’t wait for a total breakdown. Contact us today to schedule your service and stay cool and worry-free all summer.

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