Although furnaces don’t require water to run, their heat exchangers create condensation that exits your home through a condensate drain line. However, there are times when the condensation leaks out of the unit instead. This can cause rot, mold growth, and other types of water damage in your home, so it should be addressed promptly with the help of an HVAC contractor. Here are a few of the most likely causes.

What Causes a Furnace to Leak Water?

1. Broken Line

The condensate line itself is often the source of a water leak. Due to exposure to freezing temperatures or normal wear over time, condensate lines may crack and release water. Wrapping the cracks in silicone tape is an adequate temporary solution, but to prevent the leak from reoccurring, have the line professionally replaced.

2. Clogs

Condensation is supposed to travel through the line and into a pan before heading to a sewage or septic system. Its journey may be slowed or stopped by clogs in the line or pan, which gradually accumulate dirt, debris, mold, mildew, and even small insects or spiders. This may lead to backflow or overwhelm the emergency condensate pan. To clear a clog, pour hydrogen peroxide, white vinegar, bleach, or hot water mixed with detergent soap into the line.

3. Broken Heat Exchanger

A clogged condensate line may prevent air or combustion gas from circulating properly in the heat exchanger. As a result, the exchanger is likely to overheat and develop stress cracks, allowing condensation to leak out. An HVAC contractor will need to replace the exchanger promptly, as a broken exchanger may also leak dangerous fumes or start a fire.

4. Faulty Humidifier

While a clogged condensate line can overwhelm a humidifier and cause a leak, it’s also possible that the solenoid valve is broken so that it leaks water instead of evaporating it. Alternatively, the water pressure may be too high, creating stress cracks.

5. Poor Exhaust Pipe Installation

Your furnace may be equipped with an exhaust pipe that carries gas outside before it condensates. If the slope is wrong or the pipe itself is the wrong size, the gas will cool too quickly and seep out of the unit as water. Ask a professional to inspect the pipe and redo the installation if necessary.

When you have furnace problems, contact ABC Heating Cooling & Plumbing Inc. in Brookville, PA. With more than two decades of experience in AC and heating system repair, they will expertly diagnose and fix any leak at an affordable rate. They understand that emergencies happen, and their team is available 24/7. To schedule a visit, call them today at (814) 856-3211.