Have you recently noticed that your HVAC system is leaking water? Having water in your HVAC system is normally nothing to worry about since it naturally occurs as part of the cooling process and sometimes also when heating your home depending on what type of furnace you have. Here, we’ll explain what causes water to form in an HVAC system and what issues can lead to the system leaking.

An Overview of Your HVAC’s Condensate Drain System

Water naturally forms in the interior part of an air conditioning system. The reason is that when the warm air that gets drawn into the air handler meets the cold evaporator coil, much of the moisture in the air ends up condensing. This condensation is why all types of air conditioning have some form of condensate drain.

In terms of central air conditioning, the condensation drips off the evaporator coil into the drain pan below it. The water then flows out through a PVC pipe that sticks out through the side of the air handler. This pipe is then connected to one or more additional pipes that lead to a floor drain, outside of the house or directly into the home’s plumbing drain system.

High-efficiency condensing furnaces also have the same type of condensate drain system. Conventional furnaces don’t need a condensate drain since no condensation ever forms inside them. In a condensing furnace, the combination of the primary and secondary heat exchangers absorb heat. There is so much heat from the exhaust fumes that they get cold enough for the water vapor they contain to condense.

What Can Cause an HVAC System to Leak Water?

Under normal circumstances, you never have to worry about water in your HVAC since its condensate drain system ensures that all of the water drains away and empties out elsewhere. The only time you’d normally even see any water is if the condensate drain pipes lead to a floor drain near your air handler. You may see water leaking out of your air handler or condensing furnace or notice water pooling up on the floor in the area. If so, it almost always indicates that there is an issue with the condensate drain system.

The most common reason an HVAC system will start leaking water is due to a condensate drain clog. You can often end up with mold, algae and slime forming in the drain pan and drain pipes. Over time, the build-up can sometimes lead to a clog forming in one of the drain pipes. When this happens, the water can eventually back up to the point where the drain pan gets full and starts to overflow.

If the pipes lead outside or to a floor drain, you can sometimes clear the clog by attaching a wet/dry vacuum to the end of the pipe and sucking everything out. Otherwise, you’ll usually need to hire an HVAC technician to fix the issue since it’s often necessary to take the pipes apart in order to remove the blockage.

Over time, the drain pan under the evaporator coil or in a condensing furnace can get damaged and start leaking. Plastic drain pans can sometimes be prone to cracking when they get older, while steel drain pans can end up rusting through. If there’s only a minor crack, a technician will often be able to patch it and stop the leak. If the pan is rusted or has more severe damage, you’ll usually need to have it replaced. Unfortunately, it isn’t always possible to replace a steel drain pan since sometimes it’s welded directly onto the evaporator coil. In this case, your only choice is to replace the entire coil.

If you notice water on the floor near your air handler or furnace, it often means one of the drain pipes is leaking. This can happen because the pipe somehow got cracked, but it more often happens as a result of one of the joints that connect two pieces of pipe coming loose. In either case, you’ll need to replace the damaged pipe or reseal the joint. This is potentially something you can do yourself. However, it’s a good idea to seek professional help if you’re unsure of what to do just to be certain that the leak gets fixed properly.

One other time where you can potentially end up with water leaking out of your air handler is if your AC recently froze up and the evaporator coil got covered in a thick layer of ice. The condensate drain system can normally handle all of the extra water dripping off the coil as the ice thaws. However, if there is a partial clog in one of the drain lines, the water may not drain away fast enough to prevent the drain pan from overflowing.

Contact Us Today

Since 1946, AirNow Air Conditioning has been providing professional air conditioning and heating services to residents throughout the Sarasota area. We offer same-day service and can help if your HVAC is leaking or needs any other type of repairs. We’re also the company to trust for all of your maintenance and installation needs. To schedule an AC repair service call and see what makes us the top HVAC company in Sarasota, contact us today.

company icon