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Goodman Furnace Leaking Water? 4 Common Causes + What To Do

A Goodman furnace leaking water is a dangerous electrical hazard. The leak may be coming directly from the system or from connected parts. So, what’s causing the leak, and is there a way to fix it?

Your Goodman furnace is leaking water because of a cracked secondary heat exchanger, loose drain tubes, broken condensate pump, or a clogged condensate assembly. Ensure that all of these parts are clean and don’t have any cracks or bends to stop the leak.

Let’s see why your Goodman furnace is leaking and how to fix it. Some fixes are rather simple, so you won’t even have to call a technician.

Cracked Secondary Heat Exchanger

The secondary heat exchanger plays multiple roles. Its function ensures combustion gases cannot leak into your home, and the temperatures aren’t too high or low inside the furnace. 

If the secondary heat exchanger is cracked, it can cause a leak, along with several other problems. This happens when the heat exchanger allows combustion gases to pass through. The gases accumulate in the furnace and ductwork, causing condensation. 

Moreover, when combustion gases leak into your home, they can cause several health problems for your family.

How To Fix

Due to the dangers of combustion gases leaking into the ducts, this is the first thing to investigate. If a crack in the heat exchanger is behind the leak, take appropriate action before turning the furnace again. 

Note that you can’t repair a secondary heat exchanger; it can only be replaced. Check what heat exchanger your Goodman furnace uses and order the model online or try to find it in a local store. You don’t want to run into compatibility issues, as secondary heat exchangers come in various sizes. 

For guidance on replacing the secondary heat exchanger in your furnace, watch the video below: 

Loose Drain Tubes

Your furnace has a condensate drain line that consists of black and white PVC pipes and tubes. The white tubes run from the furnace to the condensate trap, where condensation liquids from the furnace collect. The liquids are then drained out of your house through the black pipes. 

Although these pipes are sturdy and are connected firmly, they can still come loose. Perhaps a family member tripped over the drainpipe but forgot to tell you. Loose drain pipes lead to dangerous leaks in the furnace. The water can build up in the surrounding region, creating an electrical hazard. 

How To Fix

Assuming the pipes aren’t cracked or damaged in any way, shape, or form, you just have to reconnect them, and the leak will disappear. Here’s what you have to do:

  1. Take a close look at all pipes in the condensate assembly. Check the pipes that lead liquids from the furnace to the condensate trap. Also, check the drain pipes that move liquids from the trap to the outside of the house. 
  2. Try to wiggle the pipes in wherever you see a connection. The pipes must be properly connected to each other. 
  3. If you find a loose connection, fasten it. Be gentle not to break the pipes in the process.

Broken Condensate Pump

The condensate pump is located along the drain pipes. It’s sometimes also referred to as a drain pump. This pump extracts condensation from the furnace. The liquids are pulled into the condensate assembly and pumped into the trap to be drained outside. 

If the condensate pump stops working, water can leak from various areas. This happens because the condensate pump can no longer pull liquids out of the furnace or your ducts. In some cases, you may notice water pooling up inside the furnace’s main compartment, which requires immediate action.

How To Fix

You first need to ensure it’s the condensate pump that stopped working. Turn the furnace on and check where the leak is coming from. Now, walk closer to the condensate assembly and locate the pump.

The furnace should be running for a while before the pump kicks in. Stand close to the condensate pump to hear it working. The sound may be subtle, depending on the size and age of your furnace. So, keep your ears close to the pump. 

If you can’t hear any sound coming from the condensate pump, this might be where the fault lies. A replacement pump is a good idea, but ask a professional to test it first. There are times when a simple fix can save you money instead of replacing the part. 

Here’s a video with the steps to replace a condensate pump:

Clogged Condensate Assembly

If the condensate pump seems to be running normally and there are no loose connections in the drain pipes, the problem may be a clog. As liquids are pulled into the condensate assembly, debris collects in these pipes. When there’s a significant amount of debris, it can block the pipes. 

In this scenario, water first starts to accumulate inside the condensate line. As water builds up, it can leak into parts of the furnace.

How To Fix

If the drain pipes in your condensate assembly are blocked, flush them out with hot water to remove debris and other objects causing the blockage:

  1. Ensure the furnace is off, then remove the condensation pipes. 
  2. Run hot water through all the pipes and see if debris comes out. You may need to run the water through the pipes for a while to get debris stuck to the sides to come loose. 
  3. Use a brush to clean the pipes.
  4. After flushing the pipes, fit them back on and fasten them. 


A crack in the secondary heat exchanger or problems with the condensate assembly can lead to water leaking from a furnace. A Goodman furnace leaking water is a danger both for the device itself and people.

If you’re experiencing other problems with your Goodman furnace, I recommend reading through our Complete Goodman Furnace Troubleshooting Guide.


  • Vincent Steele

    Vincent is a freelance writer based in Santa Ana, California. When he isn't writing articles for Temperature Master, he can be found biking or hanging out with his cat, Shelly.

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