Reasons Why Your Furnace May be Leaking Water

Why may your furnace be leaking water when the AC is on? Learn about common causes of air conditioners leaking water. Find why AC leaking water with Sandium.

Updated on Oct 23, 2023
5 min read
Reasons Why Your Furnace May be Leaking Water

HVAC systems are integral to ensuring home comfort in extreme temperatures. As long as these are in perfect working condition, your house has a comfortable indoor environment.

But if there is any malfunction in your air conditioning or heating system, it can take a while for it to get repaired and can cost you a lot.

Furnaces leaking water is a problem that many people face. There are multiple reasons as to why your furnace may be leaking water.

1. Condensation

Condensation occurs in high efficiency furnaces when heat is exchanged. Generally, furnaces have a drain tap and a condensate line that safely drains out the condensed water. A leak or clogging in either of these can cause water to leak out.

2. Malfunction in the condensate pump

The condensate pump pushes water away from your furnace and through the condensate lines. If this pump is not working properly, your furnace may leak water.

3. Metal vent pipe

High efficiency furnaces usually have white PVC vent pipes whereas conventional furnaces have a metal exhaust vent pipe. All the gases produced during the process of combustion are carried through the exhaust vents and released outdoors when they are hot.

An incorrect sized pipe for your furnace will cause these gases to get trapped inside due to extra air. This will lead to the gases cooling down and condensation taking place that can leak out of your furnace in the form of water.

4. Leaky humidifier

For additional comfort in winters, many people add a humidifier to their heating system. Humidifiers consist of constantly flowing water inside them. Any clog or leak in these might make it seem like the furnace is leaking water.

5. Leaky air conditioner

Sometimes the weather is extremely unpredictable and while it may be very hot one day, it is cold the next. In these types of circumstances, most houses will turn on their air conditioner on one day and the furnace on another.

Apart from absorbing moisture form the air, air conditioners have condensate lines and a drain pipe as well. Clogging or leaking in the air conditioner can also make it seem like your furnace has a water leak.

What to do if your furnace is leaking?

1. Power off the furnace

The first thing to do as soon as your furnace leaks water is to turn it off. Ensure that the thermostat is at the “OFF” setting and then turn the shut off valve which is located on the gas line that is connected to your furnace. Shut off also the electrical breakers which are associated with your furnace.

2. Clean up the leak

Once your electrical circuit is shut off, mop up the water that has leaked out of the furnace. A stagnant pool of water is not good for the furnace, or for the flooring. Use a wet vacuum cleaner if the spill is large.

3. Contact a technician

It is best to leave the problem and the repairs to professionals so call a technician to solve the issue.

Join the Future of Home Comfort

Take the first step towards comfortable, energy-efficient, and stress-free living by scheduling a consultation with Sandium.