Is Water Dripping From The Furnace PVC Pipe? (Fix It Now!)

Upgraded Home Team
by Upgraded Home Team

Your furnace is a vital piece of equipment for your home and is responsible for keeping your home hot in the winter and cool in the summer. This necessary appliance is a large piece of equipment that can feel complex and complicated to maintain. Seeing water dripping from the PVC pipe in your furnace can be troubling and is undoubtedly a cause for concern. Luckily, water dripping from a furnace PVC pipe is usually one of three possible problems.

Water dripping from your high-efficiency furnace PVC pipe may indicate that you have a clog in your drain line, an issue with your condensate pump, or a leak in the condensate line. Repairing a clogged drain line is an easy task that homeowners can perform themselves; however, fixing a leak or condensate pump will require a trained HVAC technician.

Part of repairing your furnace will depend on the type of furnace you have. Determining if you have a conventional or high-efficiency furnace will help diagnose your leaking PVC pipe. While a clogged drain or damaged condensate pump may be a common problem on a high-efficiency furnace, a leaking pipe on a conventional furnace may indicate a problem with the humidifier or the vent pipe.

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Does My Furnace Have a PVC Pipe?

There are two main types of furnaces. One type of furnace is a high-efficiency furnace, and the other is a conventional furnace. Determining which type of furnace you have is the first step of diagnosing a dripping PVC pipe coming from your furnace. If you see a white PVC pipe that comes out of the side of your furnace, it is safe to assume you have a high-efficiency furnace. This type of furnace is sometimes called a condensing furnace.

If instead of a white PVC pipe, you see a metal vent or pipe, this may indicate that you have a conventional furnace. Water coming from the lines on either a conventional or a high-efficiency furnace can mean a significant problem with your furnace, and it requires immediate attention to remedy the situation.

Why Is My High-Efficiency Furnace Leaking?

There are three main reasons why your high-efficiency furnace may be leaking. The reasons you may see water dripping from your furnace PVC pipe include:

  • A blocked condensate drain
  • A problem with your condensate pump
  • A problem with the condensation line

All three of these issues are related to the way the high-efficiency furnace runs. If you feel comfortable working with a furnace and have a basic understanding of how your furnace works, you may be able to repair a blocked condensate drain problem without the help of an HVAC technician.

Why Does My Furnace Produce Water?

Although it may seem counterintuitive to have a furnace produce water, the water byproduct is related to the way your high-efficiency furnace works. A high-efficiency furnace contains two heat exchangers, while a conventional furnace only contains one. Between the two heat exchangers, a great deal of heat is absorbed. When this happens, the heat that usually exists in the system as a gas converts into a liquid state. The liquid is called condensation. Usually, the condensation forms and then runs out through the condensate line located on your furnace.

Sometimes, the mechanism that helps collect and drain the water in your high-efficiency furnace becomes blocked or damaged. When this happens, the water is not able to drain properly. If there is a clog in your condensate water line, you may notice that water comes out of the PVC pipe in the furnace, or you may see water pooling around the base of your furnace.

Furnace Troubleshooting: Condensate Piping

What Tools Do I Need to Repair a Clogged Condensate Drain?

Luckily, checking for and repairing a clogged drain line is a relatively straightforward process, and many people already have the necessary tools to perform this fix. To fix a clogged condensate drain on a high-efficiency furnace, you will need:

  • Flashlight
  • Screwdriver (optional) – May be necessary to remove the access panel to the condensate pan and drain line
  • Vacuum cleaner/Shop-Vac – Using a wet/dry type vacuum is ideal
  • Plumber’s snake (optional) – Might be necessary for particularly stubborn clogs and blockages
  • Hot water, hydrogen peroxide, or white vinegar – Necessary for ongoing maintenance

How to Fix a Clogged Drain on Furnace

Repairing a clogged drain line on your furnace is relatively easy, and you only need some essential tools to complete the repair. To fix a clogged drain line on your furnace, you will want to:

Step 1: Check Drain

The first step is to look for a clog. You will want to start with the drain trap. This feature is the part of the furnace that collects dirt and debris and is prone to clogs. Usually, the drain trap is located under the air handler. Sometimes you may have to remove the access panel to see the drain. The condensate pan may also be filled with standing water, which is another indicator that your drain is clogged.

Step 2: Vacuum The Drain

To remove built-up debris in your drain, you can use a wet/dry vacuum or shop-vac to eliminate the clog. Simply position the vacuum hose at the entry to the drain and suck out the debris.

Step 3: Snake the Drain

For stubborn clogs, it may be necessary to use a plumber’s snake. This tool is a device that will allow you to enter the drain and clear any blockages that may prevent water from properly draining.

Step 4: Ongoing Maintenance

To ensure that your drain is free and clear of clogs, it is good to flush the drain after cleaning. You can use a combination of hot and soapy water, diluted hydrogen peroxide, or white vinegar to flush the drain. To prevent future backups in your condensate drain, it is a good idea to flush the drain twice per year to keep debris and dirt away.

What Happens If My PVC Pipe Still Drips After Clearing a Clog?

If you have cleared your drain line, and you still notice the water is coming from the PVC pipe connected to your furnace, you may have a more significant problem on your hands. Water dripping from the furnace may indicate a problem with the condensate pump or that your drain line is cracked or broken. These are more technical fixes, and you will want to call an HVAC technician to examine your furnace.

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Related Questions

What Happens If My Conventional Furnace is Leaking?

If you have determined that you do not have a high-efficiency furnace, you will most likely have a metal vent drain instead of a PVC pipe extending from the furnace. Water leaking from this drain will still indicate a more significant problem with the system, but the problem will be different because of how these systems are built and operate. Water leaking from a metal pipe on a conventional furnace can mean one of three things:

  • You have a leaky humidifier.
  • You have a vent pipe that was not properly designed when the furnace was installed.
  • Your furnace may leak when the air conditioning is running.

These problems tend to be a little more complex and may require a professional HVAC technician’s support. If you have a leaking conventional furnace, be sure to contact an HVAC technician to come and help resolve the issue.

What are the Benefits of a High-Efficiency Furnace?

High-efficiency furnaces are an excellent investment, and many people are opting for this furnace type in their home. The first benefit of installing a high-efficiency furnace is they help lower utility bills. These furnaces usually run at about 95% capacity, compared to a conventional furnace that may run at about 80% capacity.

A furnace that works more efficiently will help lower your utility bills, and many owners see a drastic reduction in their bill’s cost after the first month following installation. It is important to note that high-efficiency furnaces will save you money on your fuel bill, like natural gas, month to month, and will not impact the electric utility bill. The furnace will still need to run and blow hot or cool air for the same duration of time.

Further, a high-efficiency furnace is a sealed unit. In a conventional furnace, the heat is produced from a process known as “open combustion.” In this process, the furnace uses the surrounding air to pull into the system, creating hot air in return that is pumped through your house. Ultimately, this can turn into a significant safety hazard if air volume in the enclosed space is insufficient to perform the needed combustion process.

Comparatively, a high-efficiency furnace is a sealed system, drawing air from the outside. This design is a much safer furnace and is ideal for tight crawl spaces and basements.

Upgraded Home Team
Upgraded Home Team

We are a team of passionate homeowners, home improvement pros, and DIY enthusiasts who enjoy sharing home improvement, housekeeping, decorating, and more with other homeowners! Whether you're looking for a step-by-step guide on fixing an appliance or the cost of installing a fence, we've here to help.

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