What Do Furnace Flues Need in Fall?

Symptoms

• If you find rust on top of your furnace or on the flue pipes, or if you notice smells from the chimney or furnace, you might have a blocked flue or chimney. Other symptoms of flue problems include the appearance of soot around your furnace, carbon monoxide leaks, water leaks near the flue pipes, the appearance of moisture on windows or walls, peeling wallpaper or plaster that flakes.

Corrosion

• A furnace usually doesn’t produce as much soot as a wood stove, but the soot it does produce must be cleaned out of the chimney and flue system. If it’s not, the flue will corrode when sulfuric acid forms from soot and moisture found in the flue gases. The corroded pipe will then allow a poisonous gas, called carbon monoxide, to leak back into the house. The corroded flue also is a fire hazard.

Soot

• In addition to corroding your chimney and flue pipes, soot can blow back into your house when flue systems become blocked, and deposit an oily coating on everything in sight. This situation, which is known as “puff-back,” requires a professional cleanup and can costs thousands of dollars. Gas furnaces also can develop a rusty scale that is produced when gas residue combines with moisture. The scale not only allows carbon monoxide to leak into your house, it reduces your furnace’s efficiency.

Safety Inspection

• Ignoring your furnace flue and chimney system can result in expensive repairs or a fire. A certified chimney sweep should inspect your furnace every year. According to A1 Safety Chimney Service, a furnace flue cleaning is similar to a fireplace cleaning, with the exception that the sweep will check your connector pipes, too. After sweeping the flue, he will reconnect the pipes and perform a safety inspection to ensure that the flue pipes are safe and working properly.