Why Is Your Furnace Leaking Water?


In a perfect world, you’d never have to deal with surprise mishaps with your appliances. Unfortunately, issues like furnace leaks are fairly common. If you notice water pooling around the base of your furnace, you should remedy the problem as soon as possible. If left unchecked, water can cause damage to your floors, ceiling, walls, and other areas of your home.

There are a number of reasons leaks can happen. The following are common causes of water leaks in furnaces.

Condensation Pooling

Condensation is one of the most common reasons for leaks in furnaces. Most of the condensation that’s produced by your furnace escapes through a drain located on the floor. If this drain becomes clogged or breaks, condensation will begin to collect around the bottom of the furnace.

Leaking Humidifier

Another issue that can cause a leaking furnace is a leaking humidifier. Humidifiers are often connected to plumbing systems to add moisture to the air. If these devices become clogged or broken, water will most likely start to pool around the furnace.

Plumbing Leaks

In some instances, what appears to be a leaking furnace might actually be a plumbing problem. Although it may be good that your furnace doesn’t have an issue, the leaks will still need to be remedied quickly.

Clogged Filters

Your furnace filter helps to protect the blower from dust, hair, and other pollutants that the ducts pull in. It also helps to improve your indoor air quality. If your furnace filter is dirty or clogged, airflow will be restricted through the furnace coil. This will either cause water to leak around the furnace or cause the coils to freeze.

Improperly Designed Vent Pipe

The purpose of a vent pipe is to eliminate gases produced by your furnace during the combustion process and safely carry them away. Whenever everything’s working properly, these gases should escape outdoors before they’re able to cool down and turn into condensation.

If your vent pipe is too large or doesn’t have a proper slope, too much air can circulate and trap gasses inside the flue. Eventually, the gasses can form into condensation that can leak out of the furnace.

Air Conditioner Leaking

If you only notice leaking whenever you’re running your air conditioner, the issue probably isn’t your furnace at all. Your AC not only helps to cool your home, but it also helps to dehumidify it. Each time you use your air conditioner, it absorbs excess moisture from the warm air inside. This moisture drains out of your home through a condensate drain line. If the drain line is clogged or broken, water can leak around the area.

What Should You Do if You Notice a Leak?

If you notice water pooling around your furnace or leaking from it, it’s important to act quickly to avoid damage to your home. Before calling in a professional to diagnose the issue, you can try a few things on your own to see if the problem is remedied.

First, shut off the system. The shutoff switch might look like a regular light switch, and it will probably be located near the coils. If you’re unable to find the switch, you can turn off the furnace at the breaker.

After you’ve shut the system off, clean up any water that’s collected around the base. If you have a significant amount of water, you may need to use a wet-dry vacuum. Since sitting water can quickly damage whatever it touches, try to soak it up as fast as possible.

Next, inspect the air filter. If the filter appears clogged or dirty, you’ll need to replace it with a new one.

If you’re able to determine where the source of the leak or water pooling is coming from, it may give you a good indication of what the issue is. However, you’ll most likely need professional help to fix the problem.

Hire Expert Furnace Repair

Homeowners in Windsor rely on their furnaces to keep their homes comfortable during the cold winter months. If you’re dealing with water leaks or pooling around your furnace, contact the experts at Guaranteed Comfort Heating & Cooling to schedule an appointment. We’ll work to identify the issue and eliminate it within a timely manner.

We specialize in quality furnace repair, installation, maintenance, and rental services. Our knowledgeable team also offers experienced cooling, tankless water heater, HRV installation, heat pump, heat recovery ventilation system, air purification system, UV lights and air cleaner, HEPA filter, and ductless split system services.

Chris Egan


Chris Egan, owner of Guaranteed Comfort Heating & Cooling, brings over 35 years of HVAC experience. Dedicated to customer satisfaction, he delivers top-notch heating and cooling solutions.