Blog

Are you looking for help with projects around the house? Our blog offers helpful tips and DIY videos, or schedule a service appointment today.

Why Is My Furnace Leaking Water?

How to Handle a Furnace Leaking Water

So, you’ve just discovered a pool of water puddling up in front of your furnace. How did this happen? Why would a furnace leak water? More importantly, you’re probably wondering, “why is my furnace leaking water?”

These are all important questions. Keep in mind that while a leaking furnace can be a symptom of a serious internal problem, it isn’t typically a huge repair and in most cases can be easily fixed. Don’t delay the repair process and don’t attempt to handle it yourself without the right training. Call a skilled professional to handle the issue before it gets worse.

Types of Furnaces

Every homeowner facing this type of problem wants to know the answer: why does my furnace leak water? While there are several reasons why a furnace would leak water, an HVAC technician will need to know what type of furnace you have to be able to more easily identify the source of a leak.

Do you have a high-efficiency condensing furnace or a conventional furnace? A conventional furnace exhausts gases out of the home, typically through the roof, while a high-efficiency condensing furnace requires unique venting but heats air from condensed exhaust gases using a second heat exchanger, helping your furnace reach higher efficiencies.

If you’re not sure what type of furnace you have, there are some telltale signs on your actual unit. If the exhaust pipe to your furnace is a white PVC pipe as opposed to a metal pipe, that means you have a high-efficiency furnace. Additionally, a furnace with an Annual Fuel Utilization Efficiency rating that is 90 percent or higher is a high-efficiency furnace. 

Knowing what type of furnace you have helps determine why it might be leaking.

Why Do Furnaces Leak Water?

Issues with Heat Exchanger

This is one of the most expensive problems you could be facing if your furnace is leaking water. A faulty heat exchanger can cause water leakage for high-efficiency furnaces and this problem typically means you’ll need a full furnace replacement.

Condensation Leaks

Why does my furnace leak water? The most common reason is a condensation leak. If the leak is caused due to a condensation leak, it’s possible your furnace has a clogged condensation drain, clogged tubing, a broken condensation line, or other issues in the condensate pump.

Clogged Filter

Regularly changing your air filter can prevent a host of issues with your furnace, including leakage. When your furnace filter is clogged, it reduces the airflow going to your furnace coils which can cause the coils to freeze over and water collection.

Your AC is Leaking

Why is my furnace leaking? Perhaps your AC is actually to blame. Your AC often shares a drainage line with your furnace so if your AC isn’t working properly and is leaking, a puddle of water could collect around your furnace.

Whole-Home Humidifier is Leaking

Your furnace leaking water could be due to the whole-house humidifier if it’s connected to your furnace. Some malfunctions can cause a whole-house humidifier to leak inside your furnace, causing a pool of water on the floor just outside your furnace. Regular HVAC maintenance appointments can help prevent this issue.

Plumbing Leaks

Because your AC and furnace may share a drainage line, obstructions in the plumbing could easily cause a puddle of water to collect—even if there’s not an internal, mechanical issue with your HVAC system. Other kinds of plumbing leaks like poorly fitting pipes or clogged drains can also cause a puddle of water to occur.

Improper Installation

If you have a standard efficiency furnace and you have some type of water leak, it’s possible that the exhaust or flue piping was incorrectly sized upon installation. In this case, the ill-fitting piping will need to be removed and the properly sized piping installed.

How to Fix a Leaking Furnace

The first step to fixing a leaking furnace is to shut it off and put some towels down to quickly clean up the water. Check the air filter first to see if that’s the issue and replace if necessary. Next, it’s a good idea to vacuum around the PVC drain line to remove any clogs that could be present. Turn on your unit again to see if the leak is resolved.

Call John C. Flood for Furnace Repair Services

If changing out your air filter and removing any clogs in the drainage system didn’t resolve your leak, it’s time to contact John C. Flood and schedule an appointment for some help. A professional furnace repair team can inspect your furnace to fix any issues and prevent any future, more serious damage.