Furnace Repair FAQ: What Is A Furnace Exhaust Flue?

Gas furnaces are one of the most powerful forms of home heating available, capable of reaching temperatures above the range of most electrical heaters. But gas furnaces require special care to keep them running efficiently, effectively, and safely. If you have a gas furnace keeping you warm during winter’s cold days and nights, make sure to schedule maintenance annually with a trusted contractor. Don’t hesitate to call for repairs the moment you sense anything has gone amiss with your furnace.

The exhaust flue is one component of a gas furnace that must stay in good shape to maintain expected efficiency. If there’s anything wrong with the flue, you need to call a heating repair specialist. Quality Air Heating and Air Conditioning has you covered for furnace repair in Columbus, OH — any time of the day or night.

The exhaust flue and why it’s important:

The process of generating heat inside a gas furnace involves burning natural gas piped in from the main gas line. This creates high temperature combustion gas that transfers to the air from the blower unit, and then the heated air travels through the ductwork. However, this leaves behind combustion exhaust (the waste product of heat exchange,) which is a liquid vapor of carbon dioxide and carbon monoxide that needs to be safely removed from the furnace’s cabinet.

The exhaust flue is the channel where exhaust gases are carried away from the heat exchanger. Upon leaving the heat exchanger the exhaust travels up the flue, which is usually a metal pipe. The flue in older furnaces runs vertically up to the roof, allowing hot gas to naturally rise up and escape outside. Interestingly, advances in high-efficiency furnaces now allow the construction of horizontal exhaust pipes.

The exhaust flue is important for furnace safety, since you do not want the toxic exhaust vapors back-flowing out of the cabinet. But the exhaust flue is also important to maintain furnace efficiency. If exhaust gas does not efficiently exit the furnace cabinet, it starts to react with the metal components inside, causing corrosion to develop. Unfortunately, corrosion often results in the furnace needing to be replaced entirely, so any problem in the exhaust flue must be taken care of as soon as possible.

Regular maintenance is key

Unless you are a trained furnace repair technician, it is difficult to detect issues with the gas exhaust until negative effects (such as corrosion or a rise in carbon monoxide levels) become too marked. This is one of the reasons you need to have your gas furnace professionally inspected and maintained once a year. A technician will examine the exhaust flue, making sure it is sturdy and free of obstructions.

If a technician determines that you need to have the flue repaired during a maintenance visit, don’t delay: call Quality Air Heating and Air Conditioning for furnace repair in Columbus, OH right away.