Why Is My Furnace Leaking Water?

a pool of water leaking from a furnaceWhy is my furnace leaking water? It might happen for several reasons, from a clogged drainage pipe to a broken condensation pump. It’s essential to determine the cause of the leak so that it can be fixed as soon as possible, as water damage can be costly and damaging.

Water leaks from furnaces don’t happen often. Let’s say your furnace is a little older or hasn’t been checked by a technician in a while. You’ll probably have to deal with water leaks frequently in that situation.


Why Is My Furnace Leaking Water? Top Reasons

Manufacturers toughly build modern furnaces to resist the weather and last for decades. However, furnaces require routine inspections and maintenance, just as people do. Here are the top three reasons water might leak from your furnace.

Clogged Drainage Pipe

A clogged drainage pipe is the most common reason for a furnace to leak water. The pipe drains water produced when the furnace burns natural gas or oil. This water is called condensation, which can build up in the pipe if it’s not cleared out regularly.

A clogged pipe can cause water to back up and leak from the furnace. You’ll need a technician to clear the pipe to fix the problem.

Broken Condensation Pump

Another reason your furnace might be leaking water is a broken condensation pump. The condensation pump is responsible for removing water from the furnace. If it breaks, water can leak from the furnace. You’ll need to have a technician replace the broken pump.

Leaking Heat Exchanger

Another reason for water near furnaces can be a heat exchanger issue. Condensation happens due to the heat exchangers in your system that assist in heat transmission. However, a water leak might occur sometimes. Although this problem is uncommon, it may nonetheless happen.

If you eliminate all other potential reasons, experts suggest inspecting the heat exchanger for leakage. Unfortunately, fixing this issue may be expensive. In reality, the problem can indicate that you need to replace your heat exchanger. However, it’s crucial to have a competent specialist assess the property to decide the best approach.

Clogged Filter

A blocked or filthy furnace filter may potentially be the source of a water leak from the furnace. Although we utilize these filters to purify the air and maintain our health, over time, debris may accumulate in them and hinder airflow through the furnace coil. It often has the effect of causing coil freezing. But, the issue may also cause a furnace to leak water.

A specialist can resolve this problem if you discover a frozen coil or water pouring from the system.

Things to Do When Your Furnace is Leaking


If your furnace is leaking water, the first thing you should do is turn it off. Before unplugging the electrical breakers connected to your furnace, turn off the electricity at the main switch and the thermostat. After turning off each of them, you should close the valve and unplug the furnace’s electrical and gas supply.

After the furnace securely disconnects from the gas and electricity, you should mop up any standing water. If you are unfamiliar with heating and cooling systems, you should contact a furnace repair professional since most of them are complicated procedures best left to HVAC experts.

HVAC specialists are knowledgeable and talented in treating furnace water leaks, so they know where to begin the investigation. It may be disastrous to attempt to fix a furnace leak on your own, particularly if you have no experience repairing or maintaining heating systems. Therefore, for your safety, you must contact your HVAC specialist as soon as a furnace water leak occurs.

Call an Expert HVAC Technician

If you have a water leak in your furnace, the best thing to do is call an HVAC specialist. An experienced professional will know how to fix the problem quickly and efficiently. They will also be able to perform a thorough inspection of your furnace to ensure that there are no other issues that could cause problems in the future.

Regarding your furnace, it’s always better to be safe than sorry. So if you think there might be a problem, don’t hesitate to call an expert. They’ll be able to help you get your furnace back up and running in no time.


If your furnace is leaking water, it’s crucial to determine the cause and fix it as soon as possible. Water damage can be costly and damaging, so it’s best to nip the problem in the bud. Several potential causes of a furnace water leak, from a clogged drainage pipe to a broken condensation pump. If unsure of the reason, it’s always best to call an HVAC technician for a diagnosis or replacement. They’ll be able to quickly fix the problem and prevent any further damage.