Why Is My Furnace Leaking Water?

Your furnace is designed to keep your home warm throughout the cold winter months. 

So why is there a puddle of water on the floor when you walk into your furnace room? 

In most cases, moisture on the floor isn’t a big deal. However, it is a sign that it’s time to call in an HVAC technician to evaluate your furnace and make sure everything is operating the way it should. 

There are a few reasons why furnaces lead. The biggest is a condensation leak, which is relatively common in today’s furnaces. Before you call in and request a service visit, find out what type of furnace is operating in your home: a high efficiency or a standard efficiency. 

Why Is My Furnace Leaking Water?

The easiest way to tell is by finding your vent or exhaust pipe. If it’s a white, plastic PVC pipe, you have a high efficiency furnace. You can also look at the furnace itself and find the annual fuel utilization efficiency rating (AFUE). It’s often printed on a yellow energy guide sticker somewhere on your furnace. If it’s 90 percent or higher, it’s a high efficiency furnace. 

If your furnace has a metal pipe, it’s a standard efficiency furnace and shouldn’t have condensation. 

High efficiency furnaces are built to extract heat from combustion gases over longer periods of time. As this occurs, condensation may occur, which is then routed to a drain in the floor. If everything is working correctly, the water flows away from the furnace, and you won’t see pooling water. If you do, you might have:

  • A clog in the drain line
  • A break in the condensation line
  • An issue with the condensate pump

An HVAC technician can inspect the entire system, make the necessary repairs, and have your high efficiency furnace working at its best in no time. 

Standard efficiency furnaces extract heat from combustion gases and quickly vent them out through the exhaust pipe. There should be no water involved with this process. If you have a pool of water surrounding your standard efficiency furnace, other factors are at play. It could be an issue with a whole-house humidifier. Or a leak from inside your furnace. Or maybe it shares a drain with another appliance such as your air conditioner that is in need of repair. 

The only way to find the source of the problem is to schedule a maintenance visit for a thorough inspection. It’s the best way to stop the problem in its tracks, and ensure your heating system is fully operational once again. 

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