Most people donbt ever think about their furnacebs exhaust flue. They check the pilot light, occasionally the air filter, but the flue is often forgotten. Whether or not you realize it, however, the exhaust flue fills a vital role in the operation of the furnace. Letbs look more closely at what the exhaust flue does. First, webll examine why itbs necessary in the first place.

Combustion Gases

No matter what kind of fuel your furnace burns, be it wood, oil, natural gas, propane, or something else entirely, it will produce more than just heat from the fuel it burns. There are several common fuel combustion byproducts produced by normal furnace operations. Virtually all of these byproducts are toxic, but some are far more dangerous than others. One of the most deadly is carbon monoxide. This gas is odorless, tasteless, and completely invisible to human senses. The side effects of heavy exposure to carbon monoxide include nausea, dizziness, unconsciousness, and death. All furnaces produce these combustion gases. If not for the exhaust flue, these deadly byproducts would become trapped in your home.

Exhaust Flue Operation

When a furnace burns fuel, the combustion byproducts rise through the heat exchanger to the exhaust flue. The flue then vents the gases outside where they can safely disperse. Occasionally, the flue may connect to a chimney. In most cases, however, the flue simply exits out the side of the house. Despite the simplicity of the flue, there are a number of things that could compromise its effectiveness.


The first issue youbre going to want to keep an eye out for is any kind of crack or leak in the flue. This can cause combustion gases to leak into your home. Next, make sure that your flue is inspected every year for blockages. Birds will occasionally build their nests in exhaust flues, especially if they are connected to chimneys. This will trap most of the combustion gases from your furnace in your home.
If you havenbt had your furnace inspected yet this year, call Comfort Central, Inc. We provide heating repair service throughout the entire Hendersonville area.