When you return home to discover that there is a puddle of water underneath your furnace, it can be disturbing. The first reaction may be to wonder whether this is a plumbing or a furnace malfunction. This will be hard to confirm either way without an inspection carried out by a certified heating technician. Here are some reasons why your furnace could be leaking.
What Type of Furnace Do You Have?
The most common cause of a water leak in a furnace is a condensation leak. We will explore three of the common furnace water leak causes in more detail later. But, before any inspection on your furnace can begin, the servicing technician will need to know the type of furnace that you have. The usual types fitted in a home are a conventional or standard efficiency furnace or a condensing or high efficiency furnace.
Some homeowners will not know which furnace type they have, but it’s simple to find out even if you don’t have your owner’s manual to hand.
Take a close look at your furnace; if the exhaust pipe or vent is made from white PVC, then you have a high efficiency furnace. Another useful way to confirm that it’s a high efficiency furnace is to check the Annual Fuel Utilization Efficiency (AFUE) rating (where this can be found is shown below). If the AFUE rating is 90% or more, this means that you have a high efficiency furnace installed in your home.
If the furnace has a metal exhaust pipe fitted, it is a standard efficiency furnace, and it will have an AFUE rating lower than 90%. This type of furnace will not have condensation, so a condensation leak will not be the cause of the water leak.
Where is the AFUE Rating Found?
If you need to locate the AFUE rating on your furnace, it’s usually printed on a yellow energy guide sticker located on the furnace. But, if you have an older furnace, it could be printed on the vent or exhaust pipe instead. Finally, if you still have the owner’s manual the AFUE rating should be located there. If you cannot find the AFUE rating anywhere, don’t despair, it’s a handy thing to know, but the HVAC technician will be able to identify your furnace type easily.
3 Common Causes of Furnace Water Leaks
There are three common causes of furnace water leaks; they are detailed below in no particular order of how common they are or how hard they are to locate and fix.
- Condensation in the Flue Pipe
If you have a standard efficiency furnace installed it should not produce any condensation. If your furnace does create condensation, a common cause is a flue pipe that hasn’t been sized correctly for your home heating system. The heated exhaust will be cooling down, then condensing is occurring inside the pipe, and then it could stream back into the furnace and water leaks out.
- A Clog in the Drainage System
The condensation from your high efficiency furnace should flow out and then into a drain in the floor. If there is a clog or blockage in the drain line or the floor drain it could cause a water leak. A regularly scheduled service will identify this issue before it turns into a larger problem that can lead to water damage that will be expensive to fix.
- A Malfunctioning Humidifier
If your heating system is leaking water, it could be coming from the humidifier inside the furnace. If there is water leaking inside your furnace, it can cause corrosion and damage the internal components. The water pooling under the furnace could be the tip of the iceberg, and it could mean that your furnace needs extensive repairs.
How Should You Handle a Furnace That’s Leaking Water?
So, you’ve just noticed that there is a puddle of water on the floor in front of and under your furnace, what happens next? Well, you now know the three most common causes and how to find out the type of furnace that you have. You may be tempted to clean up the water, but it’s a good idea to leave it, this could help the HVAC technician to gauge the severity of the water leak.
The next thing that you need to know is that in many cases this is not a big repair job, so stay calm. Then you need to contact a local trusted HVAC company and inform them that you have a water leak under your furnace. They will send out a certified technician to carry out an inspection, and they can recommend a course of action to get the water leak fixed.
Although the water leak itself is a smaller repair job, it’s important to get it looked at quickly. The water leak could be causing damage in and around the furnace. Water damage can be expensive to fix and the longer it continues, the more it will cost. A water leak can also create issues with mold growth, and this can quickly spread to other areas. Mold is bad for the health of everyone living in your home, it can be difficult to remove, and in some cases, it may even grow back.
A DIY or Professional Repair?
It may be tempting to attempt a repair yourself or hire a handyman to get your furnace water leak fixed. This would be a mistake; a home heating system represents a significant investment that you’ve made to improve your indoor comfort levels. A furnace is expensive to repair or replace, and the last thing you need is an amateur poking around in your heating system. If someone attempts a repair without the necessary skills, experience, and tools, they can easily damage expensive components. Fixing a water leak is a relatively simple task for a certified HVAC technician, and it’s not likely to be an expensive repair. It’s a better idea to hire a professional and get the job done right the first time.