Inisght on Why Your Furnace Could Be Leaking

Nothing is more alarming than coming home from work and you notice a puddle of water on the floor by your furnace. Is your water heater leaking and will you have to replace it? Most likely, that puddle originated from your furnace. Here's what you need to know about a leaking furnace.

Where Does the Water Originate?

If your furnace has a condensing unit, it's supposed to produce water. You'll learn more later about this type and how to tell if you have one. Rather than vent away combustion gases, a condensing unit pulls a lot of heat from those gases before allowing them to dissipate. As the gases cools down it condense into water, then drains away. This is where your water originates.

If water is collecting on the floor, there could be a problem. The kind of problem depends on your furnace type: conventional or condensing. Here's how to tell which one you have:

Spot the Difference

There are two simple ways to determine the difference between conventional and condensing. One is to check the Annual Fuel Utilization Efficiency rate, or AFUE. This is located on the yellow Energy Guide paper on the side of your furnace. A rating above 90 means you have a condensing furnace. If the number is below 90, your furnace is a conventional one. If your furnace is older and does not have this rating, it is most likely a conventional one.

Another way to tell is by looking at what your exhaust pipe is made of. This pipe connects to the furnace and guides combustion gases away. It the pipe is metal, your furnace is conventional. If your pipe is white PVC, your furnace is condensing. There might be more than one PVC exhaust pipe present.

Conventional Furnace Problems

Conventional furnaces do not naturally produce any water. Two reasons for the presence of water could be:

The humidifier is leaking: Your furnace may have an attached humidifier, which adds moisture to the air as it's blown into your house. This small unit has water, electricity and drainage hookups, and may leak if the filter is clogged.

The exhaust pipe needs adjusting: Normally, the exhaust pipe directs gases away from your home before they have a chance to cool and condense into water. Gas movement slows down if that pipe is too big or doesn't slope upwards enough. Instead, it cools and condenses into water, which ends up on your floor.

Condenser Furnace Problems

Condenser furnaces, however, are meant to produce water. If you see a puddle, here's what could be wrong:

The drainage system is clogged: Typically, water drains out of a small white pipe from the furnace, along the floor, and to a floor drain. Water will puddle on the floor if it cannot reach this drain. A clog somewhere inside the condensation line or drain system might cause water to exit the furnace elsewhere and not reach the floor drain.

Condensate pump went out: This pump acts as a tiny sump pump, and pushes condensation toward the right draining area. Many high-efficiency furnaces have one. If it doesn't work properly, or stops altogether, water overflows from the furnace.

Heat exchanger is bad: Your furnace may have more than one heat exchanger, which cool the gas as it moves along the passageway. The first exchanger performs the bulk of the cooling process, and any other exchangers after that produce more condensation as a result. If the passageway holding the first exchanger is damaged or cracked, condensation will find a way out and puddle on the floor.

Depending on the problem, you can adjust the furnace yourself. Otherwise, local AC services need to stop the leak in your furnace.

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