Arrived home and realized that your furnace is leaking? Don’t let this frustrate you. Troubleshooting the cause of a leaking furnace is often fairly simple.  If the leaky furnace is complex, the owner might have to contact their manufacturer or a professional. Therefore, there are a few arguments as to why your furnace is leaking. These reasons can be either major or minor. In this article, we will have a look at the causes of a leaky furnace and how to fix condensation leak in furnace. Experiencing a leaking furnace is a sign that something is not functioning correctly somewhere in the system. We strongly advise that you regularly maintain your HVAC system to prevent future problems.

Condensing or Conventional Furnace 

If you’re facing furnace leaking issues at your home during winter, you might want to consider the type of furnace you own. For instance, condensation problems are much more common with high-efficiency furnaces. Looking at your furnace’s exhaust pipe, you can easily distinguish its make or type. If it has a PVC exhaust duct and a 90+ AFUE rating, it is a condensing (high-efficiency) furnace. On the other hand, a conventional (standard-efficiency) furnace shouldn’t produce any water or leakage. If a conventional furnace is leaking, it is a complex issue.  Contact an HVAC expert immediately. 

Reasons for a Leaking Furnace 

Before we look at fixing a condensation leak in a furnace, we have to go through the possible causes of leaking from your condensing furnace. If you notice a furnace leak, you need to fix it right away. A slow reaction will only cause more damage to your home, starting from the floor to walls and even your ceiling. Leaving the water there will possibly lead to mould growth in your house.  Let’s check out the common furnace leak reasons: 

Why regular furnace maintenance is important.

Heat exchanger 

Previously, people thought that condensate production was an issue only for air conditioners. Condensation occurs even in furnaces as well, especially if it’s a high-efficiency one. Having a problem with your heat exchanger can lead to water leaks to your furnace. Although furnaces have a long life span, heat exchanges are expensive to fix and could lead you to replace the entire heating system

Humidifier clog 

Clogging or breaking of your humidifier might be a reason for your furnace leaking. The humidifier is connected to your plumbing system to introduce moisture to the air. Therefore, a cracked, broken, or clogged humidifier will cause a leak on your furnace at some point, causing water to drip around your furnace.

Condensation leakage 

Condensation leaks are typical for high-efficiency furnaces, i.e., 90+ AFUE rating. These furnaces have a double heat-exchanger that helps produce more heat—the output of heat results in condensation, which flows through your home drainage pipes. Mostly, the extraction happens through your floor drains. Suppose your drain pipes become clogged or broken at any point. In that case, you’ll start experiencing a condensation leak around your furnace’s base. Remember to drain the water off the floor to avoid unnecessary damage around your house. 

Related: What Can Cause a Furnace to Stop Working?

Blocked Condensate trap 

Condensate traps extract acidic condensate in a high-efficiency furnace. A clogged or broken condensate trap could result in a liquid overflow. Surplus condensate affects the furnace’s unit performance and shortens its overall lifespan. Look-see if your condensate might be out of place since disconnection can lead to a leak as well. 

Poor vent pipe design 

As mentioned earlier, all conventional furnaces have a metallic flue pipe that safely carries exhaust gases produced during combustion out of your house. Typically a conventional furnace removes combustion gases from the heating system before they convert to vapour. Check out your flue pipe to see if it has a slope or if it’s leaky. If yes, reach out to the professionals for further repairing assistance. 

When You Notice a Furnace Leak, Do this:

Before we conclude, here is what you do when you notice a puddle of water around your furnace: 

Turn off the system 

Find the shut on/off button similar to a light switch adjacent to your furnace and coil, then turn it off. If you cannot access the switch button, go to the system’s circuit breaker and shut it off. 

Clean up 

Get rid of the water sitting on the floor immediately to avoid further floor, walls, or even your ceiling as well. 

Examine the filter 

Check your air filters to ensure they are not obstructing airflow. 

Vacuum clean 

Put your vacuum cleaner around the PVC drain line to get rid of any possible clogs. After cleaning, switch your furnace system on to check if the leak has stopped. 

Pour some water on top of your condensate pump 

If your condensate pump is not responding, this might be a sign of mechanical complications in the system. If it manages to pump water, you have a clear drain-line running from the pump to the drain. 

Final Word: How to Fix Condensation Leak in Furnace

We’ve concluded this item, and you should have a basic understanding of how to fix condensation leaks in the furnace. If you don’t think this is a DIY fix, contact an HVAC professional to assess your furnace. Remember to set a maintenance schedule for your furnace to minimize breakdown cases and maximize your system’s efficiency.