Many homeowners are somewhat mystified by the way their furnaces work. They know that when the burners ignite, the fan comes on and the heat is distributed through the duct work. But there’s also a key part inside a furnace known as a heat exchanger. It’s important to know what it does, and how to detect the signs that all is not well with it.

Read on for how to deal with a cracked heat exchanger.

What a Heat Exchanger Does

Basically the heat exchanger separates the flames from the air in the home. The fuel burning in the combustion process warms up the heat exchanger, which in turn warms the air.

The heat exchanger contains the fumes such as carbon monoxide, carbon dioxide, water vapor and soot that are given off during combustion. The heat exchanger then conducts fumes to the chimney or flue while the heat is transferred into the home.

A Cracked Heat Exchanger

Over time, the heat exchanger can crack. This results from the continuous heating and cooling of the metals. Cracking may also occur when the furnace can’t get enough airflow and the heat exchanger overheats, suffering excess stress from expanding and contracting.

Dirty air filters are one major cause of heat exchanger cracks, as dirt prevents good airflow. The cracks usually occur around welds or bends. Undersized ductwork also creates airflow problems that can result in cracks.

An oversized furnace, which never runs long enough to evaporate condensation, can also cause a heat exchanger crack due to rust from the condensation.

Signs of a Furnace Crack

A crack in the heat exchanger will let air from the blower out, which then interferes with the flame, causing a flutter or roll out. This can shut down the furnace.

A crack can also emit deadly carbon monoxide into the home.

Have your heat exchanger checked annually for cracks, but be aware that minute cracks are not always dangerous. Dangerous cracks are usually visible with the naked eye.

For more on a cracked heat exchanger, contact Powers Heating and Air of Peachtree City.