Keller, TX – If you find your AC system has frozen up, it is generally because of an airflow problem or lack of refrigerant.
1.) Your air conditioning system is not getting enough air. The most common reason this happens is because the filter needs to be changed or vacuumed. Dirt and debris from the air comes in through the return air vent and gets trapped by the filter. This is great because now your air conditioner is not sending that dirty air back into your house through the vents. But eventually all that dirt and debris starts to block the airflow. AC systems need steady airflow to function properly. If the airflow is reduced, the system will likely freeze up.
Other causes of reduced airflow include collapsed or dirty ducts, although this is typically more rare. However, if the AC has ever been used without a filter, clogged dirt becomes much more likely. Once dirt is in the ac system, it can travel all the way to the coil and become trapped. Another cause of no airflow is a problem with the blower motor. The blower motor blows the air, so if it is not blowing air then the trapped air will freeze.
2.) The ac system is low on refrigerant (Freon or Puron, also called R-410A). If the air conditioner does not have enough refrigerant it can freeze up. Since the refrigerant is in a closed loop system, the only way you would be low on refrigerant is if your AC system has a leak. Now, some leaks are very slow. With slow leaks, the homeowner might simply get a little refrigerant put in their system once a year or so. We recommend a leak stopping repair be made when we add the refrigerant. But other types of leaks are large and unrepairable. Refrigerant leaks are generally the primary reason why people need to buy a new air conditioning coil.
Leaks generally happen because the metal rusts, and then as the rust falls off because of wind, rain, or just an aging system, little pinhole sized holes appear in the metal. Eventually those little holes get bigger as more of the metal rusts, and eventually large holes are no longer able to retain the refrigerant in your system. Once you have larger leaks, replacing the evaporator coil usually becomes necessary.
What to do next:
Turn off the cooling function on your air conditioning system but keep the fan running. Do this for several hours until the system has thawed. If you have not changed the filter in the last 30 days, check it for dirt. So if you cannot easily see light through the filter, then we recommend that you replace the filter.
If changing the filter solves your problem, you are good to go. While you are doing a little home maintenance on your AC equipment, it is also good to hose down your outside coil to remove any built up dirt or pet hair. This helps your AC to run more efficiently. However, hosing down your system can also remove rust and expose small holes that have begun to form (from the rusting metal). So while you help your system run more efficiently by cleaning the coil, an old rusted system is trickier in this situation.
Next, once you have turned off the AC but kept the system on “fan” mode, do you still hear the fan running? Typically when the fan is not running, then the problem is the fan motor.
If you live in Keller, Southlake, and North Richland Hills, TX, we can come diagnose the exact problem for only $29. When we arrive (or when you book the appointment), mention the coupon on this website and we will waive the $29 fee. Call or text (682)214-4822 or easily book your appointment online.