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If you’ve ever experienced a furnace breakdown in the middle of winter, you know how costly and frustrating it can be. To avoid this, it’s essential to keep your furnace in good condition by fixing any leaks that may occur. But, do you know how to fix condensation leak in furnace?


Finding the root of a leaky furnace’s problem is often not too difficult. The owner may need to contact the furnace’s manufacturer or a specialist if the leaking furnace is complex. However, there are several explanations for why your furnace is leaking. These causes may be significant or insignificant.


A condensation leak is one of the most common problems with furnaces and can be easily fixed if you follow these simple steps.


Condensation Leakage

High-efficiency furnaces with an AFUE rating of 90 often have condensation leaks. These furnaces include a second heat-exchanger that aids in producing additional heat. Condensation is produced as a consequence of the heat output and travels via the drainage pipes in your house.


If you have this type of furnace, check the PVC pipe that goes from the furnace to the outdoors. It is where the furnace releases the condensation. When there’s a leak in this pipe, you may need to replace it. Your condensation leak may come from the drain pan if you don’t have a high-efficiency furnace. In this case, the problem is usually a clogged drain line.


Fixing a Condensation Leak

Turn off your furnace if you think your condensation leak is coming from the PVC pipe. Then, locate the clean-out tee or cap at the end of the pipe. If there’s no clean-out tee or cap, you’ll need to install one. Once you’ve located it, unscrew the cap and look inside the pipe.


If there’s water in the pipe, your condensation leak has been fixed! If not, you may need to replace the pipe. To do this, measure the length of the old pipe and cut a new one to the same size. Then, glue the new pipe to the old one and screw on the clean-out tee or cap.


If your condensation leak comes from the drain pan, you’ll need to unclog the drain line. To do this, remove the furnace’s access panel and locate the drain line. Then, use a wet/dry vac to suck out any dirt or debris blocking the line. Once you’ve unclogged the line, put the access panel back on and turn on your furnace.


Malfunctioning Heat Exchanger

Another possible reason for a condensation leak is a malfunctioning heat exchanger. The heat exchanger is what produces the heat in your furnace. If it’s not working correctly, it can lead to excessive condensation and leaks.


If you think your heat exchanger is the problem, you’ll need to call a professional to look at it. They’ll be able to tell you for sure and can also fix the problem if it is indeed the heat exchanger.


Blocked Condensate Trap 

The condensate trap is what prevents water from backing up into your furnace. If it becomes blocked, it can cause a condensation leak. In a high-efficiency furnace, condensate traps remove acidic condensate. A liquid overflow might be due to a condensate trap that is blocked or damaged. The performance and longevity of the furnace are both impacted by excess condensate. Check if your condensate is out of position since disconnecting may cause a leak.


Humidifier Clog

If you have a humidifier attached to your furnace, it could be the culprit of your condensation leak. A humidifier adds moisture to the air to prevent dryness. However, if it becomes clogged, it can cause excessive moisture and lead to leaks.


To fix this problem, you’ll need to clean out your humidifier. Turn off your furnace and unplug the humidifier. Then, remove the water panel and empty any water that’s inside. Next, use a brush to clean the inside of the humidifier. Once finished, put everything back together and turn on your furnace.



If you have a condensation leak in your furnace, don’t panic! In most cases, it’s a relatively easy problem to fix. Just follow the steps outlined above, and you should be able to get rid of the leak quickly and easily. And, if you’re still having trouble, call a professional for help. They’ll be able to diagnose the problem and get your furnace working properly again in no time.


Call Furnace Repair Vaughan for any furnace concerns. Furnace Repair Vaughan is your local HVAC and furnace repair provider. We are available 24/7 for any repair services you may need. Give us a call today to schedule a repair!

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