What Is an Evaporator Coil?

The evaporator coil is part of the cooling system, it cools the warm air from your home before it is recirculated back out of the system as cool air. As there is moisture in air, especially in humid climates, water forms as the air is cooled, and it is expelled from the system into a drain pan and then down the drain pipe.

If there is a problem with the evaporator coil it is likely you will have a leak, and you will see the pooling of liquid around your air conditioning unit.

What May Cause a Leak?

There could be a fault in the system. Components may be worn, such as a rusty drain pan, or dirty, a clogged drain pipe. If your drain pipe is clogged the water has nowhere to go and will end up back in your home. You may also have a dirty air filter, which can block the flow of air into the evaporator coil.

Alternatively, your evaporator coil could be rusted due to the buildup of formic acid. It forms when volatile organic compounds (VOC) react with the copper in the coil.

How to Prevent a Problem from Happening

1. Regular cleaning of the drain pipe would stop it from clogging. You can use a wet-dry vacuum to remove any debris.
2. Having an annual service. Using an evaporator coil cleaner will remove the dirt building up on the coil before it becomes a problem and clogs the drain.
3. Replacing a drain pan that is becoming rusty (another issue which can be identified during an annual service)
4. Checking the air filter regularly and replacing it as necessary.
5. Preventing the buildup of formic acid by reducing the use of household chemicals such as household cleaners and aerosols, and installing a whole house air purifier

What to Do When a Leak Occurs

Some small issues can be checked by the householder – clearing the drain and replacing the air filter for example. However, the evaporator coil is part of the cooling system of your air conditioning unit and has refrigerant flowing through it. Refrigerant is a hazardous pollutant and you should never undertake maintenance to any refrigeration system.

We would recommend you call an engineer. We can visit you to do a thorough inspection and identify the cause of the problem. If your evaporator coil has been frozen, we will need to check whether it has been damaged. If necessary an evaporator coil replacement will be carried out.