How to Replace an Air Conditioner Evaporator Coil

An AC unit.
What You'll Need
New coil
Hand tools
Electrical testing equipment
Refrigerant gas
Soldering equipment

The air conditioner evaporator coil is one of two main components that produces cold air, which is then routed through the duct system and delivered to the interior of the home. Replacing the air conditioner coil is a job for a trained and certified technician, not the average do-it-yourselfer. The coils are not simply a bolted in part that can easily be swapped out, but is a network of coiled metal tubing that serves to chill hot air. Additionally, the cooling agent used (such as freon gas) is an element that will need to be captured and properly disposed of due to environmental concerns. Allowing coolant to leak out into the environment result in heavy fines if caught. Here you will information on the common steps that are followed and the materials used in the replacement of an air conditioner evaporator coil replacement.

Step 1 - Inspect Coils

The first step is to visually inspect the coils. If they are damaged or cracked, they will likely need to be replaced. A trained HVAC (heating, ventilation, and air conditioning) technician can confirm if replacement is necessary. It may be useful to have one come out to identify exactly what is wrong with the unit and provide an estimate for repairs. In fact, get a couple of estimates to get a good idea not only of the expense to repair, but the extent of the work needed.

Step 2 - Remove the Coil

If the coils are cracked, most likely any refrigerant has already escaped into the environment. In this case, removal of the coils consists of cutting the inbound and exit tubes.

Step 3 - Replace the Coil

Once the old coils have been removed, the new one can be installed by inserting it in the existing ports, then soldering it in place, usually with a silver solder.

Step 4 - Recharge the Coolant

A vacuum will need to be put on the system to remove any air from the lines and make sure coolant is at the proper levels. If it is not, the coolant may be replaced or added to (which is referred to as been charged or recharged). If a different type of coil was needed due to unavailability or using an obsolete type of coolant, other components such as controls and/or the compressor, may also need to be replaced, but components such as ducts and the blower will likely not need to be replaced.

Step 5 - Test the Air Conditioner

Once all of the above steps have been completed, the air conditioning system will need to be tested. The power supply needs to be restored, and the system turned on by setting the thermostat in the home to "cool" and lowering the desired temperature on the thermostat. This should initiate the air conditioner to start up. If it does not come on, additional testing of other components may be required.