Signs of Trouble with Your Furnace Exhaust Piping

February 28, 2023

It’s almost time to turn your furnace off for the season. Your heating system has gotten you through the winter just fine. While it may seem like a momentous occasion is approaching, now’s not the time to ignore potential issues. Problems with the furnace exhaust piping can prevent it from venting correctly, which can disrupt airflow, cause the unit to malfunction, and release toxic gases and fumes. 

The Dangers of a Poorly Ventilated Furnace

The concern is mainly with gas furnaces. They produce byproducts such as carbon monoxide that can cause headaches, nausea, dizziness, and fatigue; in high concentrations, exposure can lead to unconsciousness and death. The gas is colorless and odorless, which is why carbon monoxide alarms are required in your home.

A backdraft is another hazard with blocked furnace exhaust piping. It happens when not enough air gets to the furnace, so there’s an insufficient amount of oxygen for combustion. Air will get sucked down the flue, preventing exhaust fumes from venting upward.

How to Identify a Furnace Exhaust Problem

The signs of an exhaust issue can be subtle. Your furnace may be running and heating your home, but the following symptoms may be present:

  • Condensation on Windows: If your windows are damp or fog up in the morning, moist gas fumes may be collecting on the cold glass instead of venting outdoors.

  • Rust: Moisture from gas fumes can sit on metal components and eventually cause them to corrode; you’ll see rust on the grillwork and the front of the furnace.

  • Soot: Dark soot may be seen collecting around the vents. It may also be blown back into your home and build up on furniture, carpets, and other surfaces.

  • Leaking Exhaust Pipe: An exhaust pipe leak is a common problem with a high-efficiency furnace. Normally, condensation drains via a pipe and floor drain, but a clog or crack in the pipe can create a condensation leak. If a standard furnace’s exhaust pipe is leaking water, it may be corroded or have a loose joint.

  • Signs of a Gas Leak: A condensation leak is often accompanied by a gas leak. If water is leaking from the flue pipe, check for bubbles in the water; this is a telltale sign of a gas and/or carbon monoxide leak. Leave your home immediately and call for help.

How to Check Your Furnace Exhaust Piping

The flue pipe is an insulated metal pipe that connects your furnace to the chimney or other vent on the outside of your home. A cover or screen usually protects it from animals and debris. However, blockages can still occur, causing your home to fill with fumes. Ash can fill the flue as well, while scale (a mixture of gases, fumes, and moisture) can form inside it and cause a clog.

To inspect the flue pipe, remove the flue cap and look for any obstructions. If you can, remove them; otherwise, call a professional to clear the pipe. Once the flue is clear, replace and secure the cap. Other signs of blockages include rust on the flue pipe or water streaks along the outside of it.

Have Your Furnace Exhaust Piping Cleaned Out by a Professional

It’s best not to take chances with your heating exhaust system. At Service Champions, we provide furnace maintenance services that include checking the exhaust pipe for proper venting and testing for carbon monoxide. Request help if you notice signs of trouble with your furnace exhaust piping, or schedule a 21-Point “WOW” Furnace Tune-Up today. To get started, call 833-600-0991 now.

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