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Possible Culprits for Frozen AC Coils

July 27, 2022

If your AC runs but doesn’t cool your room, the AC has visible moisture, or the coils have visible ice around them, those are signs that your AC coils may be frozen. Unfortunately, frozen AC coils are a common problem during the summer. The problem compromises the efficiency of your AC, and if you don’t rectify the issue soon, you could be stuck in a hot, humid, and uncomfortable home all summer.

The first step to protect your AC coils from freezing is to learn the potential culprits.

The Air Filters Are Dirty

The AC coils need a steady supply of air to function correctly. But air must first pass through the system’s air filters, which remove dirt, dust, and other airborne contaminants from the air before the clean air gets to the coils.

After a while, the collected dirt and debris may accumulate and block the air filters. Consequently, air will have a restricted passage, and only a small amount of air gets through the filters and into the AC coils. Lack of air means that the coils cannot absorb heat, so they become too cold and may eventually freeze.

To avoid this problem, clean your air filters regularly or change them per the manufacturer’s directions. Besides protecting the coils, clean air filters can  
lower energy bills by up to 15%. Moreover, your AC won’t strain much to cool your space, which prolongs your system’s lifespan.

The Refrigerant Is Low

The AC requires adequate refrigerant to absorb heat from the indoor air and release the hot air outdoors. Therefore, if your AC starts to cool unevenly or doesn’t cool altogether, inadequate refrigerant is the most probable cause.

Moreover, the AC cannot draw heat if the refrigerant level is low. As a result, the coils get too cold and freeze.

Other than frozen AC coils, you can tell if your AC has a low refrigerant level if the system produces a hissing noise. Therefore, call a professional HVAC technician if you suspect the system may be low on refrigerant. The professionals will inspect the AC comprehensively to diagnose the problem correctly.

The Condenser or Evaporator Fan Motor Is Broken

The condenser has a fan that helps circulate air over the coils. If the condenser fan motor is faulty, the coils will not get adequate airflow. Again, the lack of sufficient air over the coils causes this component to become too cold and may freeze.

You can also quickly tell if the condenser fan is broken if it stops to run. Call a professional to diagnose the problem.

Again, the AC coils are prone to freezing if the evaporator fan breaks. The evaporator coil works similarly to the condenser coil. The only difference is that the condenser is outdoors while the evaporator is in the indoor AC unit.

You may be able to tell that the evaporator fan motor is broken if you hear a humming noise from the indoor unit, but no air comes out of the vents.

The Drainage System Is Blocked

The AC has a drainage system that removes water that forms as the coils absorb heat from the indoor air. If this system blocks, perhaps due to dirt and debris accumulation, water will accumulate around the coils and freeze them. Water may also damage other components in your AC unit.

You can unblock the drainage system with a vacuum cleaner, but only if you have the necessary tools and skills. Otherwise, you may cause further damage to the AC unit. Leave the task to a professional HVAC technician for a quality work guarantee.

Frozen AC coils put your AC at risk of premature wear. But you can prevent the issue through regular system inspection and maintenance. So don’t wait for your cooling system to fail to contact us for repairs. Instead,  
contact us at Comfort Solutions
to schedule a comprehensive inspection. We will identify any underlying problems and solve them before they get out of hand.