What Everyone Needs To Know About HVAC Systems

Why Your Furnace Vent Pipe Could Be Leaking Or Blocked And How The Problem Is Corrected

by Amelia Martin

When your gas furnace heats up your home, it creates byproducts of combustion that are routed out of your house through a vent pipe called the flue. These gases can be harmful if they accumulate in your home. One of the gases created by your furnace is carbon monoxide. Since it's vented away, the gas doesn't pose a danger, but if there's a leak in the flue, dangerous carbon monoxide could accumulate around the furnace and spread through your home. Here's a look at some reasons the vent pipe might leak or become blocked and what repairs can be done.

What Causes A Furnace Flue To Leak

The flue is usually made of galvanized metal, so it lasts a long time, but it's still vulnerable to corrosion as it ages. When the pipe develops rust spots that eat through the pipe, gas can escape. This might lead to chronic low levels of toxic gases leaking in your home or a sudden problem that releases a large amount of gases in the house. Leaks can also develop when the joints on the ends of the pipe work loose and allow gas to escape.

Other Problems That Can Affect A Furnace Flue

The vent pipe from your furnace runs from your furnace up through the ceiling and out the roof. If your house has a chimney, the flue connects to it. Besides leaking, a vent pipe will give you trouble if it gets blocked. It might become blocked if the cap on top is missing and debris gets blown inside or an animal or bird builds a nest in the pipe. If the flue is in the chimney, a decaying chimney can drop parts in the flue that cause a blockage. Any blockage causes gases and smoke to build up and flow in your house rather than escape through the roof.

The Furnace Repairs That Might Be Needed

You should always have a carbon monoxide detector near your furnace because this alarm could be your first indication of a problem with the furnace flue. You might also suspect problems if you see rusty places on the pipe or if you notice the cap is missing. You might see condensation on your furnace or your home might develop a bad odor. If you suspect problems with the vent pipe, call a furnace repair service to take a look.

If the pipe is rusted, the old pipe can be removed and a new pipe put in its place. Blockages should be removed if they're present and if the cap is missing, it should be replaced to keep out debris. The flue on your furnace is checked when you have annual cleaning and maintenance done so repairs can be done if necessary before the pipe starts leaking. Still, the flue might develop a leak during the heating season in a joint or due to old age or moisture problems in your home, and if a leak should occur, furnace repairs should be done promptly to prevent exposing your family to toxic gases.