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Reasons Why Your Furnace Might Be Leaking Water

Noticing that there is water pooling up around your furnace can be a worrying experience. Nonetheless, the odds are fairly good that this problem is not nearly as serious as it may appear. There are a number of different reasons that your furnace might leak or have water pooling around it. Fortunately, most of the causes aren’t all that serious, and they can be fixed fairly easily.

High-Efficiency Furnace Leaks

Leaks are much more common with newer high-efficiency furnaces than they are with conventional furnaces. The reason behind this lies in the design of high-efficiency furnaces and how they work. Also known as condensing furnaces, high-efficiency units contain two heat exchangers instead of just the one found on conventional furnaces.

This secondary heat exchanger allows these furnaces to extract much more energy from the fuel by burning it longer and more efficiently. This added time also means that the combustion gases created by burning the fuel have more time to cool down before being expelled through the exhaust system. When these gases cool down, they also create condensation, which is exactly what makes them more prone to leaking. This condensation means that high-efficiency furnaces need a way to drain the water away from the system. This is accomplished through the use of a drain line, drain pan and floor drain.

Any clogs, leaks or damage in these components can lead to water leaking out of the furnace instead of draining away as it should. A clogged condensation line can obviously cause leaks, but it can also cause water to build up inside the drain pan and potentially overflow. This same issue can also cause the drain pan to rust or develop leaks. Similarly, a clogged floor drain can lead to water pooling up around the furnace instead of going down into the sewage system, which is more of a plumbing problem than an HVAC issue. The good news is that most of these issues are fairly easy to diagnose and repair.

Unfortunately, there is one other problem that can cause high-efficiency furnaces to leak, and this one is generally much more severe. A broken or malfunctioning secondary heat exchanger can also cause water leaks. When this is the case, you’re usually only left with one option, to have the furnace replaced.

To get your furnace leak properly diagnosed, CONTACT US to setup an appointment. We service the Indianapolis, Indiana southern suburbs. We are located just 38-minutes south of downtown Indianapolis, IN.

Leaks From a Conventional Furnace

When working properly, conventional furnaces don’t produce condensation and are thus less prone to leaks. If the system is leaking, the cause is almost always related to an improperly designed or poorly fitted vent pipe. These problems can lead to the combustion gases from the furnace staying inside the vent pipe for longer instead of immediately being funneled outside the home. When this happens, the gases can cool and lead to condensation. If you notice water leaking from the vent pipe itself, or if the vent pipe has no slope to it, this is almost assuredly the issue you’re dealing with.

Other Possible Causes of Furnace Leaks

There are a number of other potential issues that can cause your furnace to leak, such as an issue with your air conditioner or whole-home humidifier. If you notice water leaking around your furnace after running your air conditioner, it could be that the condensation from your AC is the real culprit. In this case, it could again be an issue with a broken or clogged condensation line or floor drain. This problem can also occur when you run your furnace and air conditioner within a short time of one another, which can overwhelm the drain pan and cause it to overflow.

If you have a whole-home humidifier, this could also be what is causing the water leak. These systems are installed directly into your HVAC system and utilize a steady flow of water to increase the home’s humidity level. This water can obviously make humidifiers more prone to leaking. Nonetheless, it is usually fairly easy to check if the humidifier is the cause of the water leak. Simply inspect the outside of the unit and the feed line and drain line for any visible signs of leaks, clogs or damage.

Professional Heating and Cooling Services

If you notice water leaking around your furnace, the expert HVAC technicians at Dugan Air Heating & Cooling are on hand to diagnose and repair whatever issues you’re facing. We also offer the full range of heating and cooling services for customers in Franklin and the surrounding areas. From furnace and air conditioner installation to maintenance and repairs, we can handle it all, including ductless HVAC systems and heat pumps. We also offer numerous solutions to help you improve your indoor air quality.

Looking for reliable, professional heating or cooling services? Contact Dugan Air Heating & Cooling today to schedule an appointment.



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