Melting Away the Hassles: Common Causes of Frozen AC Coils

As the temperature rises during summer, your air conditioner becomes your best friend, ensuring you stay relaxed and comfortable. However, what happens when your AC unit starts blowing cold air or, worse, accumulates ice? This can be a sign of underlying issues within yours that require immediate attention to prevent further damage and restore optimal performance. Let’s delve into the common causes of frozen AC coils and how you can thaw out of your comfort zone.

Understanding the Evaporator Coil:

Inside your air conditioning system lies the evaporator coil, which absorbs heat from the indoor air. As warm air passes over the coil, moisture condenses on its surface, leading to the desired cooling effect. However, when this moisture freezes, it can hinder the coil’s performance and disrupt your comfort. Regular maintenance and prompt attention to any signs of freezing can help ensure your system operates smoothly throughout the year.

Reason Behind Frozen Evaporator Coil:

A malfunctioning air conditioner can swiftly turn a relaxing summer day into an uncomfortable one. Understanding why a frozen evaporator coil is essential for restoring your system’s functionality and maintaining indoor comfort. Let’s explore these causes in detail and provide practical solutions to address them effectively.

  • Airflow Restriction: Any blockage or hindrance in the airflow within the HVAC system, often caused by dirty filters, blocked vents, or a malfunctioning blower fan, which can lead to inadequate heat exchange and coil freezing.

  • Low Refrigerant Level: This occurs when the system has insufficient refrigerant due to leaks or improper charging, resulting in the evaporator coil becoming too cold and freezing.

  • Condensate Drainage Issues: Problems with the drainage system that lead to the buildup of condensate water, potentially causing water damage and hindering system performance.

  • Malfunctioning Defrost Cycle: The defrost cycle in heat pump systems fails, leading to ice accumulation on the outdoor unit and impaired efficiency due to restricted airflow.

  • Improper System Sizing: When the HVAC system’s capacity doesn’t match the space’s heating or cooling requirements, issues like excessive run times, short cycling, and reduced efficiency result.

  • Coil Cleaning: Regular maintenance involves removing dirt and debris from the evaporator and condenser coils to maintain efficient heat transfer, prevent coil freezing, and prolong the system’s lifespan.


A frozen evaporator coil can significantly impact the performance of your AC system, leading to discomfort and potential damage. However, by addressing the root causes, such as low refrigerant levels, airflow restrictions, dirty air filters, condensate drainage issues, and regular coil cleaning, you can prevent the coil from freezing and ensure optimal operation of your HVAC system.

For professional assistance with your HVAC system, including any issues related to evaporator coils, trust Kean Heating and Cooling. With our expert services and years of experience in the industry, we are dedicated to keeping your home comfortable and relaxing year-round. Don’t hesitate to contact us to schedule an appointment to meet all your heating and cooling requirements. Let us manage the technical aspects for your uninterrupted comfort.


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