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furnace leaking water

Why Is My Furnace Leaking Water? | DIY Troubleshooting

 Is it normal for a furnace to leak water?

The Short answer is, it depends….

There are a few different reasons that can cause your homes furnace to leak water. Some furnaces naturally produce water, but many times if it’s an unusual amount it may be best to figure out where the leak is coming from.

Water leaks can cause significant damage to your property, especially in large amounts. It’s always best to approach the situation as quickly as possible to minimize any damages.

So, we made a list of some of the causes for your furnace to leak water.

Furnace Condensation / Internal Drain System Clog

High efficiency furnaces with AFUE ratings over 90 typically have a cool exhaust and produce condensation inside the furnace. This is one of the things that make it different from a standard efficiency furnace.

High efficiency furnaces naturally produce condensation as a by-product of the natural gas burning. This is typically flown out of a PVC pipe that comes from the furnace and drains into the floor drain in your furnace room.

However, if this tube becomes clogged, or if the drain on your floor becomes it can cause water to backup and leak out of the furnace.

If you have a standard efficiency furnace, usually 15 plus years old, it should NOT be leaking water. If this is the case it could be an incorrectly sized flue pipe which is making water to drain back into the furnace.

If this is the case, it’s best to call your local furnace repair team.

Broken Condensation Line / Condensate Pump

As stated above, some furnaces naturally produce condensation. This is drained through the condensate line. If this line is broken or cracked, you could have a leak.

However not all homes have a drain in the floor. In this case you would have a condensate pump that does what it sounds like. It pumps the condensation out of your home instead of letting it drain to the floor. This could also have issues and create leaks.

Faulty Secondary Heat Exchanger

On high efficiency furnaces you could also have a secondary heat exchanger issue. This can be an expensive fix, that’s why it is best to hire a qualified furnace technician to properly diagnose the issue with your furnace and prevent damaging internal parts.

Issue With The Furnace Humidifier

According to Dictionary.com relative humidity is defined as “the amount of water vapour in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature”.

What this means is humidity requires water, and so does the humidifier in your home. If your home has a humidifier you can potentially be seeing water leaking from this piece of equipment.

Sometimes cracks can happen right at the humidifier, but your furnace humidifier could also be leaking back into your furnace. If you have had an annual tune-up recently typically this may not be your issue but if you haven’t it would be good to consider having a tune up service.

Clogged Furnace Filter Causing Coil Leak

Most people wouldn’t consider a clogged filter to cause water to come out of the furnace however regularly changing your furnace filter is crucial to the proper operation of your furnace.

If you have a central air conditioner in your home, you will have a coil located above your furnace. This essentially sucks the heat out of the air causing your air to cool, thus air conditioned or cooled air blowing through your home.

If your filter clogs there will be less air flow over this coil causing it to freeze, which can then pool up with water and cause it to leak inside your furnace.

Be sure to make sure your filters are clean and replaced allowing proper air flow.

See our article here: How often to change your furnace filter

What should you do when you notice your furnace leaking water?

If you notice an unusual amount of water coming from your furnace you should do your best to mitigate the issue. Turn off your furnace as soon as possible.

There should be a switch in the furnace room that will do this.  Clean up and dry up as much of the water as possible. If your filter is dirty, remove it and replace it with another.

Once everything is dry you can do your best to determine where this water is coming from. Most likely in all situations you should call your local furnace technician but, in this case, you will be able to better describe your leaking water issue.

If you need more assistance with your furnace and need a top-rated company, learn more about JPS Furnace & AC here

Call 403-510-1204