In last week’s blog, one of the common air conditioner problems that we mentioned was a frozen evaporator coil. This problem is so common that we thought it deserved its post! So today we’re going to talk about why evaporator coils are susceptible to freezing and what you should do if it ever occurs in your home.

Why does a frozen evaporator coil occur?

Your evaporator coil is responsible for absorbing heat from your home’s air. When this happens, condensation naturally builds up on your coils. Normally this isn’t a problem. But if something goes wrong with the cooling process, that condensation can freeze over and cause your air conditioner to break down.

What are the potential causes of a frozen evaporator coil?

  • Inadequate system airflow. One of the most common causes of a frozen evaporator coil is the lack of system airflow. This can be due to anything from closed-off air registers to malfunctioning air handlers. If there isn’t enough air blowing over your evaporator coil, the coil won’t have enough heat to absorb. This will cause the condensation on the coil to freeze over.
  • Dirty air filter. A dirty air filter will restrict airflow to your system, which will cause the same problems we listed above. In addition, a clogged filter can allow dirt to build upon your evaporator coil (below) and lead to freezing.
  • Dirty evaporator coil. If dirt builds up on your evaporator coil, the coil will have a hard time absorbing heat from your home’s air. Without that heat, your coils will get too cold and freeze over.
  • Low refrigerant.If your system doesn’t have enough refrigerant (either due to a leak or an improper refrigerant charge), it will not be able to perform properly. One of the most common symptoms of low refrigerant is a frozen evaporator coil.

What should you do if you experience a frozen evaporator coil?

If you notice that your evaporator coil has frozen over, contact Jerry Kelly Heating & Air Conditioning so we can find the source of the problem. It’s helpful if you turn off your air conditioner before we arrive at your home so that it can defrost by the time we get there. After we discover the source of the problem, we’ll fix it and advise you on how to avoid it from happening again!

If you have any questions about the proper placement of your thermostat, or if you’d like a cooling system serviced or installed in your home, contact Jerry Kelly Heating & Air Conditioning, your St. Charles, MO, air conditioning company. We service the St. Louis area, including towns like St. Peters, Town and Country, and Weldon Spring.

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