By Action Cooling & Heating / Blog / 0 Comments

Reasons Your Air Conditioning Unit Is Freezing Up

Your air conditioner makes your home comfortable by providing cold air. However, when your unit is covered in ice, it won’t work efficiently. An air conditioning unit that is freezing over won’t properly cool your home. Worse, leaving the problem unaddressed can cause water damage in your ceilings and walls. You will also have to deal with expensive AC repair.

There are many reasons your AC unit freezes up:

  • faulty thermostat
  • refrigerant leak
  • clogged drain line
  • clogged filter or broken fan

When any of these problems are caught in time, you will be able to keep your unit up and running. If you left the unit freezing up for too long, it can have a negative impact on the system, which may lead to compressor failure. The cost associated with repairing a severely damaged AC unit will make replacement a much cheaper option.

Dealing with AC units that freeze up

If your air conditioning unit has failed to cool your space, you have to take a look at your unit and check the coils. If there’s frost or ice on them, immediately turn off your unit. Avoid turning up the thermostat temperature and completely turn it off.

Unfreezing the unit

It is essential that you unfreeze your unit safely so you don’t cause any damage to its components. While it might be tempting to remove the ice yourself, you need to call an AC service technician to address the problem. When melting the ice, you need to make sure that the drip won’t harm your ceilings or walls. A professional AC technician knows how to chip away the ice without causing further damage to your unit’s coil fins.

You can try these techniques while waiting for a service technician:

  • Turn on your system fan making sure that the thermostat is set to the fan setting to prevent AC from running. This step melts the ice but may take a few hours. Skip this step if there’s ice on the fan.
  • In case the fan is not working or you want the ice to melt faster, use a blow dryer for the process.
  • Clean up the water dripping outside the drain pan with a wet vac. Don’t allow water to stay in the ducts as they can encourage mold growth.

While performing these steps, you might also want to check your air filter. If the unit is clogged, this is the main reason it is freezing up. For the unit to function properly, it requires warm air to flow over the coils. A clogged filter deters your cooling system from producing cool airflow, causing the air conditioning unit to freeze up. You can address the problem by changing out your filter. However, if these steps still don’t solve the problem, you need to call an HVAC technician to perform a thorough inspection.

Addressing the problem by calling in the HVAC professionals

A professional needs to diagnose the problem at this point. If the problem isn’t with a clogged filter or the ice doesn’t seem to melt, you should not turn the air conditioner back on without an inspection from the pros. There is a possibility of refrigerant leaks, which cannot be fixed on your own. If there are multiple leaks, the air conditioner will start freezing up again, burning out your compressor.

When you call an HVAC technician for inspection, you might unveil these problems:

Malfunctioning thermostat – If your air conditioner is running constantly even when the temperature is not high, there might be a problem with the thermostat not sending the signal to the unit. The coils tend to wear out when your unit runs constantly and this problem can cause your air conditioner to freeze up. Recalibration or replacement might be able to resolve the problem.

Faulty fan – Another issue that you need to watch out for is the system fan. Have you attempted to melt the ice, but it still fails to turn on or continues to run sluggishly? This might be the reason your air conditioner is freezing up. Since there is a lack of airflow over your coils, this is one of the reasons the unit gets too cold. Your HVAC technician will recommend replacing the fan motor or the electrical components of your unit.

Leaky refrigerant – The refrigerant refers to the chemical that ensures your coil runs efficiently. It is responsible for removing the heat by changing the pressure and temperature. Once refrigerant leaks occur in the coils, there will be reduced pressure in your refrigerant lines, causing coils to freeze over.

You should also keep in mind that your unit doesn’t consume refrigerant because it’s a closed system. Avoid adding refrigerant if your unit has a leak. If you have been advised to add refrigerant to your unit every year, it is an indicator of a leak that should be fixed immediately.

For older systems which have been purchased before 2010, your unit might still have the refrigerant R22 or Freon. By January 2020, this refrigerant will be phased out according to the Environmental Protection Agency (EPA). This means that if your older air conditioning unit fails, fixing it will be much more expensive.

Preventative measures

The good news is that most of the causes of a cooling system freezing up can still be prevented or fixed. The problem often starts small, and so long as you address it right away by considering annual maintenance and tune-up, you can keep refrigerant leaks and airflow issues at bay.