How to Replace the Evaporation Coil in an Air Handler

An evaporator coil is the part of the air-conditioner that transfers energy into either cool or warm air.

It is essential to any air-conditioning and heating system. Although evaporator coils are built to last a long time, they do break sometimes. Leaks, either refrigerant or water, are the number one reason most evaporator coils fail, according to Alan Boleware, a air-conditioning service technician in Indian Harbour Beach, Florida. Other reasons for coil failure are corrosion, a build up of dirt or the coil wears out. Replacing an evaporator coil may require working with refrigerant, which requires EPA certification.

Turn the power off to the air handler (inside unit) and condenser (outside unit) at the breaker box.

Recover/remove refrigerant, if needed, from the condenser using a refrigerant recovery machine as directed by EPA guidelines. Move to the air handler when the recovery is complete.

Remove the panels from the air handler.

Cut the PVC condensate line going into the air handler then unscrew the left-over piece from the drain pan.

Use the torch to disconnect the copper line feeding into the unit. Heat the solder to approximately 1200 degrees or until it is soft.

Slide the coil out. Slide the new coil in.

Solder the copper line back to the coil.

Screw the PVC piece back into the drain pan and connect the cut PVC line with a PVC coupling. Replace the air handler's panels.

Things You Will Need

  • Refrigerant recovery machine
  • Refrigerant--R22 or R410A
  • Soldering torches
  • Solder
  • PVC
  • Hack saw
  • Manifold gauges


  • You will have to evacuate the system to remove all the air and moisture from the lines then recharge the system per manufacturer's instructions after you have replaced the coil. This must be done by an EPA-certified technician by law.
  • Wear eye protection and gloves when using torches and refrigerant.

About the Author

Julie Boleware has been writing since 1997. She has been published on the Internet Public Library and various websites. Boleware's interests are in arts and entertainment and business. She holds a Bachelor of Arts in communications from Cameron University and a Master of Library and Information Science from Florida State University.