How to Remedy a Frozen Evaporator Coil

How to Remedy a Frozen Evaporator CoilA/C systems are a complex combination of mechanical, electrical and plumbing components that utilize refrigeration principles to cool your Palm Beach County home. The evaporator coil is the cooling element in this mix that pulls heat out of indoor air. If warm air is blowing from your vents, a frozen evaporator coil may be the problem.

Frozen Evaporator Coil

Very cold refrigerant inside the evaporator coil extracts heat energy from warm return airflow. During this cooling process, moisture is extracted from the air in the form of condensation on the evaporator coil. In a well-operating A/C system, the condensation falls into the condensate pan and drains away.

Adversely, the condensation may freeze on the cold evaporator, which diminishes the A/C’s cooling ability. Following are common A/C problems that can cause ice to form on the evaporator coil:

  • A clogged air filter blocking airflow.
  • Unbalanced supply and return airflow.
  • Dirt and grime build up on the evaporator inhibiting heat transfer.
  • Low refrigerant.
  • Faulty electrical parts overworking the system.

What to Do

Begin troubleshooting a frozen evaporator coil by turning off the A/C so that the ice can melt. Switch the thermostat to fan-on to expedite the melting process. Check all air filters for dirt and change them as needed. If the filters were dirty, wait for the ice to melt completely before testing the A/C. If the ice returns, do the following:

  • Open all interior doors and vents to ensure free airflow to return grilles.
  • Check the evaporator for dirt once the ice has melted. If it’s dirty, use a foaming coil spray to clean the evaporator.
  • If the evaporator freezes again, there is a mechanical or electrical problem that requires the attention of an HVAC technician.

For more information about remedying a frozen evaporator coil, please contact us at NisAir Air Conditioning and Heating for service.

Our goal is to help educate our customers in Martin, Palm Beach, St. Lucie and Indian River Counties in Florida about energy and home comfort issues (specific to HVAC systems).  For more information about evaporator coils and other HVAC topics, download our free Home Comfort Resource guide.

Credit/Copyright Attribution: “iQoncept/Shutterstock”

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