In certain conditions, leaks can develop around the evaporator coils in a central AC system. There are a few things homeowners with central HVAC systems should know to manage indoor AC leaks. This guide will explain two possible reasons your central AC is leaking indoors so you can address the problem and prevent water damage around your air conditioner.

1. Clogged Condensate Drain

The condensate drain is located in a drain pan beneath the AC evaporator coils. This drain connects to a hose that runs outdoors. Water that drips from the coils carries dust and other impurities with it, and sludge can build up inside the drain over time. The condensate drain can also be a hiding spot for mold colonies and algae.

You can clear minor condensate drain clogs with a cup of white vinegar. Turn off your AC and flip your AC breaker, and then locate the drain pan by removing the furnace access panel. The condensate drain is a PVC pipe with a plastic cap that is connected to the drain pan.

Remove the drain cap and pour the vinegar into the drain. Give the vinegar thirty minutes to an hour to dissolve the sludge in the drain, and then try running your AC again. If the condensate pan is still draining slowly or leaking around the edges, an HVAC technician may need to unclog the condensate drain.

2. Frozen Evaporator Coils

If your evaporator coils have frozen over, the condensate drain may not be able to keep up as the coils thaw. You will need to stop using your air conditioner and place towels around the coils to absorb moisture until they thaw. If your furnace filter is dirty, it can cause the evaporator coils to freeze by blocking airflow. To prevent this, remember to clean or replace your furnace filter at least once per month.

Another common cause of frozen evaporator coils is low AC refrigerant. A low refrigerant level reduces the pressure inside your evaporator coils and allows them to reach below-freezing temperatures. An HVAC professional can check your central AC refrigerant level and recharge the system when needed. Your technician will also locate and patch any refrigerant leaks to prevent coil freezing in the future.

Clogged condensate drains and frozen evaporator coils are two of the most common causes of indoor central AC leaks. With these tips, you can handle these common problems and keep AC leaks to a minimum. For more information about maintaining air conditioning systems, contact a local HVAC service.