How To Check Your Furnace Flue Each Heating Season

Posted November 25, 2019

In Chicago's icy cold winters, your furnace is indispensable, burning gas or oil to keep your home comfortable. During this combustion process, dangerous gases are produced. This includes sulfur dioxide, nitrogen dioxide, and carbon monoxide. These gases must be vented outside to keep your home safe. This is the job of the flue, a large metal pipe that extends from the furnace to a chimney liner or an independent flue pipe. How to Check Your Furnace Flue Each Heating Season The flue brings combustion gases safely through your home and up through the roof, expelling them above the roofline. Any blockages, leaks, or damage to the flue could allow combustion gases to enter your home, with dangerous or even deadly health consequences.

What Causes Flue Problems in Chicago Homes?

Combustion gases can enter your home from the flue when there is:

  • A leak in the pipe
  • A blockage due to a foreign object in the flue
  • Backdrafting

Backdrafting happens when the furnace cannot draw sufficient air from the interior of your home to fuel the combustion process; instead, it must draw air through the flue itself, carrying the combustion gases with it. Flue problems can occur due to:

  • Corrosion: Combustion gases contain significant amounts of moisture and acidic compounds, which can corrode steel flue pipes over time, creating leaks.
  • Loose joints: Loose joints can occur as the flue expands and contracts with temperature changes over time, causing leaks.
  • Flue pipe damage: If the flue pipe is damaged due to an accident or incorrect installation, it can restrict airflow and cause backdrafting.
  • Insufficient airflow: If your furnace cannot access enough air for combustion it will backdraft. This can be caused by a powerful exhaust fan creating negative pressure. It may also result from too many fuel-burning appliances in a small mechanical room or an HVAC system that is not properly balanced, creating negative pressure that draws combustion gases inside.
  • Chimney damage: If your flue connects to a chimney liner or runs through the existing chimney, things like broken tiles, bricks, or other debris can fall into the flue and block it.
  • A missing flue cap: If the cap is missing where the flue pipe exits the roof, debris can fall into the flue, or animals like birds can build nests in the pipe during the summer.

Need help checking the flue and furnace at your Chicago home? Call 888-868-6667 or contact ABC Plumbing, Sewer, Heating, Cooling and Electric online now!

How To Find Your Furnace Flue

The furnace flue will usually be located on the top or the rear of the furnace. It will directly connect to a chimney or to a metal flue pipe that extends vertically to the roof. Most of the remaining pipe will be hidden as it passes through your home, though it may be visible in the attic.

How To Check Your Chicago Home's Furnace Flue

Checking your flue pipe consists mainly of a visual inspection. Before each heating season, check the flue pipe for signs of damage, such as corrosion, holes, loose joints, water stains, white streaks, and sooty deposits on the pipe or furnace. From the ground, you may also be able to spot a missing flue cap or chimney damage. For a thorough flue inspection, however, it is best to call a professional for HVAC maintenance service. An expert at ABC can make sure your flue is in good condition, free of blockages, and drafting properly.

Schedule a Flue Inspection & Furnace Maintenance in the Chicagoland Area

At ABC, we're proud to offer top-of-the-line furnace maintenance services throughout the Chicago area. When you contact us for a furnace tune-up, we will thoroughly inspect your flue, check the condition of the pipe, measure flue gases, and more. Plus, we'll check, clean, and adjust all other major components of your furnace to ensure it's ready to work reliably all winter long! Call 888-868-6667 or contact us online to schedule a flue inspection and furnace maintenance in Chicago!

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