What Is Causing My Furnace to Leak Water on the Floor?

November 17, 2021
Leaking Furnace in Nacogdoches, TX

Realizing that there is water leaking from your furnace can be surprising. Still, there is usually no need to panic. Most furnace leaks are caused by fairly minor issues, and repairing these issues is usually fairly simple and straightforward. With this in mind, here are some of the possible reasons why your furnace may be leaking.

High-Efficiency Furnace Leaks

Water leaks are most common with high-efficiency condensing furnaces. Compared to conventional furnaces, the units utilize two heat exchangers. This addition of a secondary heat exchanger allows these furnaces to produce heat much more efficiently, but it also makes them more prone to leaks.

Standard furnaces only burn fuel for a short amount of time and then immediately vent the resulting combustion gases out of the building before they have time to cool down and condense. However, high-efficiency furnaces burn the fuel for longer and more efficiently. As a result, the combustion gases stay inside the furnace for longer, which results in cooling and condensing into liquid.

This condensation is the reason that these furnaces are more prone to leaking. When everything is functioning properly, the condensation should drain away from the furnace. However, any problems with the condensation line, drain pan or floor drain can result in water pooling up around the furnace instead of draining away.

These potential issues are usually the most common culprit for furnace leaks. Nonetheless, the leak could be a result of a faulty secondary heat exchanger. If this is the case, it may be necessary to have the furnace replaced.

Causes of Leaks in Standard-Efficiency Furnaces

Standard-efficiency furnaces shouldn’t produce condensation if everything is working correctly. If you do notice that your conventional furnace is leaking, the problem is almost assuredly related to the exhaust pipe and not the furnace itself. If the exhaust pipe is either too big or improperly designed, it can lead to a buildup of combustion gases. In this case, the gases might cool down and condense and thus cause leaks. If this isn’t the case, then the problem is likely related to something other than your furnace.

Leaks Related to Plumbing, Air Conditioning or Other Systems

Whole-home humidifiers, air conditioners and even your home’s plumbing could all be responsible for the leak as well. Humidifiers require a constant flow of water to function properly. As a result, any damaged or clogged feed lines or drain lines could cause water to leak and collect around your furnace.

Similarly, the water could be coming from your air conditioner instead of your furnace. Specifically, the problem could be related to a damaged condensation line or floor drain issue. Your AC’s condensate drain line is most likely located next to or even on top of your furnace and air blower. As a result, any leaks in this line often look like they’re coming from the furnace.

Both air conditioners and high-efficiency furnaces have a condensate drain line that either runs into a floor drain or directly into your sewage system. If this drain system is clogged or damaged, it can result in water building up around or near the base of the furnace. A blocked sewage line can also cause water to back up inside your home. In this case, water might start coming back up through your floor drain and pooling up around the furnace.

The fact that furnace leaks can potentially be related to so many different issues means it is essential that you seek professional assistance as soon as you notice the leak. Water damage can be expensive and lead to numerous other problems. Therefore, it is vital that you get the underlying issue taken care of as soon as possible.

Trusted Plumbing and HVAC Services

If you have noticed that your furnace seems to be leaking, the professional team at Nacogdoches Sheet Metal, Plumbing & Air Conditioning, LTD. can diagnose and repair whatever problem is causing the leak. Our team consists of both HVAC technicians and plumbers, which means we can handle the job no matter what the underlying cause of the leak is. Drain cleaning, drain repair and sewer repair are just a few of the services we offer. We also specialize in all types of heating and cooling repairs, as well as maintenance and installation. If you’re looking for ways to improve your indoor air quality, we offer numerous solutions that can help with that as well. Whether you’re looking for HVAC services, plumbing or sheet metal fabrication, give Nacogdoches Sheet Metal, Plumbing & Air Conditioning, LTD. a call to see what we can do for you in Nagodoches and throughout East Texas.