If you’re reading this in the comfort of your perfectly cool, comfortable home, you have your AC systems evaporator coil to thank. It’s the component in your AC system that absorbs heat from inside your home and works hand-in-hand with the condenser coil to complete the process that produces cool air.

And when it’s not working properly, it doesn’t take long to realize something is amiss. Read on to learn the signs that your evaporator coil is in distress so you can act swiftly and prevent costly repair or replacement.

Blowing Warm Air

If you notice warm air blowing from your vents, it could mean the evaporator coil is damaged. A damaged evaporator coil cannot effectively absorb heat and can also lead to refrigerant leaks. Contact a licensed HVAC professional to inspect the coil.

Water or Refrigerant Leaks

Refrigerants undergo a continuous cycle of compression, condensation, expansion, and evaporation. When the evaporator coil is damaged, refrigerant may escape from the system while cycling through, leading to cooling capacity losses and water leaks. If you notice signs of pooling liquids near the unit, have the unit inspected promptly.

Failure to Start

While various factors can prevent a central air system from starting, such as faulty wiring or a tripped circuit, a damaged evaporator coil can also be responsible if it has resulted in a refrigerant leak. This can reduce cooling capacity and efficiency and, in some cases, cause the unit to completely freeze up.

Frequent Stopping and Starting

If your AC system cycles on and off more frequently than usual, a damaged evaporator coil may be to blame. A damaged coil’s ability to efficiently absorb heat from the passing air is compromised. This causes the AC unit to struggle to maintain a desired temperature, and in doing so the unit may cycle on and off frequently. Frequent cycling can place excessive strain on the compressor, potentially leading to further damage and costly repairs.

Unusual Sounds

When refrigerant leaks from a damaged evaporator coil, it creates imbalances in the system, leading to disruptions that can generate a range of sounds such as hissing, bubbling, or gurgling.

Dust or Soot Buildup

Dust and soot can accumulate on the evaporator coil over time, especially if an AC unit does not receive regular maintenance. If you see dirt or darkened areas within the unit or on the coil itself, schedule a professional inspection and cleaning to keep your system operating at max efficiency.


Corrosion on an AC unit can indicate a damaged evaporator coil and resulting refrigerant leak. It’s important to address corrosion immediately to prevent the cost of an entire HVAC unit replacement.

If you’re noticing any of the above signs, contact Relief Cooling & Heating today. Our family of home comfort specialists is dedicated to providing your home’s cooling system with the necessary services your system needs to ensure reliable service summer after summer. Contact us today to schedule service.