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Should My Furnace Be Leaking Water?

large-furnaceHomeowners who have boilers to provide heat to their homes know that water leaking from the system is always a possibility. But if you, like the majority of homeowners in the area, use a gas furnace to provide heat for the winter, you won’t expect to see water leaking out of it. After all, a furnace generates heat through gas burners that create hot combustion gas. Water shouldn’t be involved.

But furnaces can leak water—and that isn’t normal. If you spot water starting to pool around the base of your furnace during the winter, you’ll need to have it professionally repaired. You can rely on our experts to fix your furnace in Raleigh, NC or in the surrounding areas. Our technicians are NATE-certified to see that the job gets done fast and gets done right the first time.

Where is the water coming from?

You’re probably curious why a furnace might leak water in the first place. It’s a good question to ask, because it gets down to some of the basics of how a furnace works.

If you have a standard non-condensing furnace, the leaking water may be due to blockage inside the exhaust flue. To generate heat, the furnace collects the hot combustion gas from the burners inside a metal container called the heat exchanger. The vapor left over after heat exchange must be exhausted out of the exchanger through a flue that leads to the roof. If this flue is blocked, the vapor will condense inside the flue and turn into water. The water will then drip back down into the system.

Water leaks are more common with high-efficiency condensing furnaces (which can achieve AFUE ratings up to 98.5%). In this type of furnace, there are two heat exchangers. The second condenses the vapor from the first in order to extract more heat. This creates water moisture, which is channeled out a tube to a drain. But drains can become clogged, and the tube can develop breaks in it, and these will lead to water leaking out of the furnace.

Another possibility with a condensing furnace is that the second heat exchanger has cracks, allowing water to drip right out of it. This is an expensive repair, since it requires putting in a new heat exchanger. In many cases, we recommend having a new furnace installed as a more cost-effective solution.

Finally, the water leaks may not actually be from the furnace at all. If the furnace shares the same cabinet with the AC, condensation from that system may be dripping out of the pan and onto the furnace. If your air conditioner has already been running this season, this might be the problem—and it still requires professional repairs. If you have a whole-house humidifier, this may also be behind the water leaks.

Regardless of the source, do not attempt to track it down or fix it on your own. Gas furnace diagnosis and repair must only be carried out by a certified technician—it’s a matter of safety! Let our experience team get to the root of the leaking issue and have it taken care of correctly.

Look to Comfort Master Heating & Air Conditioning, Inc. for excellent HVAC services in the Raleigh Area.

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