Reasons Why Your Furnace Might Be Leaking Water

Noticing water pooling up around your furnace can be a worrying experience, but the odds are fairly good that this problem is not nearly as serious as it may appear. Your furnace might leak or have water pooling around it for several reasons, such as leaks, clogs, or damage. Fortunately, most aren’t all that serious and can be fixed fairly easily. Read on to learn more about why your furnace leaks occur and what to do if it happens in your home. 

Understanding Water Leakage from Your Furnace

Leaks are much more common with newer, high-efficiency furnaces than conventional ones. The reason behind this lies in their design and operation. Also known as condensing furnaces, high-efficiency units contain two heat exchangers instead of just the one found in conventional furnaces.

This secondary heat exchanger allows these furnaces to extract more energy from the fuel by burning it longer and more efficiently. The added time also means that the combustion gasses created have more time to cool down before being expelled through the exhaust system. When these gasses cool down, they create condensation, which exits through a drain line, drain pan, and floor drain. If something malfunctions within the system and the condensation does not drain properly, it can drip out of your furnace and leak into your home. 

Conventional furnaces are much less likely to leak as they don’t produce condensation. If the system leaks, the cause is almost always related to an improperly designed or poorly fitted vent pipe. These problems can cause the combustion gasses from the furnace to stay inside the vent pipe rather than immediately being funneled outside the home. When this happens, the gasses can cool and lead to condensation. 

Common Reasons for a Furnace Leaking Water

Clogs, leaks, or damage to your furnace’s components can cause water to leak out instead of draining away as it should. Some of the most common culprits of a leaking furnace include:

• Clogged condensation line: If the condensation line is blocked, water can build up inside the drain pan and overflow out of the pipe. This same issue can also cause the drain pan to rust and develop leaks. 
• Clogged floor drain: If the floor drain is clogged, water pools around the furnace instead of going down into the sewage system.
• Broken secondary heat exchanger: A damaged secondary heat exchanger can cause excess condensation to overwhelm the drainage system and pool around the furnace. When this is the case, you’re usually only left with one option: to have the furnace replaced.
• Air conditioner malfunction: If you notice water leaking around your furnace after running your air conditioner, condensation from your AC could be the real culprit. If you run your furnace and air conditioner within a short time of one another, it can overwhelm the drain pan and cause it to overflow.
• Damaged vent pipe: If you have a conventional furnace, a broken or improperly installed vent pipe can cause condensation to accumulate inside the exhaust system and eventually leak out. 

What to Do If Water is Leaking from Your Furnace

Turn the unit off immediately if you notice water dripping or pooling around your furnace. Once you shut the unit down, use a dry towel to soak up as much water as possible to prevent damage to the surrounding area. Next, inspect the unit for visible signs of damage or clogged components.

If you’re unsure what’s causing the leak, it’s best to contact a reputable technician to assess and repair your furnace. They have the tools and experience to identify the root cause and repair it to prevent further damage. Often, the repair will be an easy fix, and your furnace will be back up and running before you know it.

How to Prevent Water Leakage in Your Furnace

The best way to prevent furnace leaks is to schedule annual maintenance with a qualified HVAC company. They’ll perform a complete inspection, cleaning, and tune-up of the system to ensure everything works correctly. If they uncover any issues that could lead to a potential leak, they’ll fix them before they progress. 

Call Dugan Air for Furnace Repair in Indiana!

If you notice water leaking around your furnace, the expert HVAC technicians at Dugan Air Heating & Cooling are on-call and ready to help! Our technicians will quickly diagnose and repair whatever issues you’re facing to restore your home’s comfort as soon as possible. 

We also offer emergency HVAC services for customers in Franklin and the surrounding areas. From furnace and air conditioner installation, maintenance and repairs, we can handle it all. We also offer service for ductless HVAC systems, heat pumps, and indoor air quality. Contact our team today to schedule an appointment!

Frequently Asked Questions

Can a dirty filter cause a furnace to leak water?

If your air filter is dirty, it can stop air from flowing through the furnace properly and cause the coils to freeze. When the coils eventually thaw, the excess water can overwhelm the drain pan and cause condensation to leak out of the furnace.

How much water should be coming out of the furnace?

A high-efficiency condensing furnace should produce around one to five gallons of water per day, depending on your local climate and humidity levels. If you notice a significant increase in water volume, contact our team for an inspection to rule out any issues.