Why Is My AC Leaking Water?

AC water leaks are more common than you might think, but that doesn't make it any less alarming when you notice a pool of fluid forming underneath the unit. Your AC leaking water is not typically a sign of a significant problem, but it may require maintenance from a skilled technician.

When it comes to an AC unit leaking water, there are usually a few specific culprits. These include:

Some of these issues are relatively simple to find and resolve, while others need the expert eye and hand of a professional HVAC technician.

The evaporator coil is an integral part of your AC unit. As hot air blows over the coil, refrigerant inside the coil absorbs the heat. Moisture then condenses into water on the coil and drips into a drain pan before draining through the condensate line. Over time, the evaporator coil begins to fail. It becomes dirty and slows down as the refrigerant within it leaks into the AC unit itself. Without any heat, the coil steadily becomes colder, freezing the unit. Eventually, the entire unit will fail. Your AC unit leaking water is one of the main signs of a frozen evaporator coil.

A clogged condensate line is one of the most common problems that result in an AC leaking water. This drain line carries condensate from the evaporator coil, disposing of it outside the unit. However, minerals, mold, dirt, and other debris may clog the drain line, causing the water to leak elsewhere. Fixing this can be as simple as vacuuming out the line with a wet/dry shop vacuum.

For water to leave your unit, it must first collect within its drain pan. As the pan fills, the fluid drains out through the condensate line. However, if the drain pan has developed a leak, all that fluid may start dripping out of the AC unit. Drain pans are often simple to replace yourself, but if that doesn't fix the issue, contact a professional HVAC technician.

The condenser is the central part of your home's entire AC system. It houses the refrigerant gas your evaporator coil uses to cool the air. As the name states, the condenser condenses the gas into a liquid and then passes it to the evaporator coil. The refrigerant liquid then travels to the compressor, where it becomes a gas once more and returns to the condenser. Should the condenser break or fail, you would have no refrigerant to cool the air. Beyond this, you may notice a leak and a hissing noise.

Another problem with the refrigerant could also result in an AC leaking water. As with a damaged condenser, no refrigerant means no cooling and a dripping unit. Noticing a refrigerant leak can be extremely difficult. One of the biggest giveaways is the presence of a sweetish smell. If you believe your AC unit might be leaking refrigerant, an HVAC technician has the tools and skills to discover and repair the leak.

Another of the more common sources of an AC leak is a malfunctioning thermostat. Specifically, your thermostat may fail to cycle the system correctly. This results in the unit overworking itself, potentially leading to other breakages. In some cases, ice may even form on the evaporator coil before falling into the drain pan, contributing to leaks. If you have a malfunctioning thermostat, you may notice that the AC won't turn off or on at the right times. You may also notice that the actual temp doesn't match what your thermostat says.