Propane Furnace Problems With the Primary Heat Exchanger

Cracking

• Whenever the furnace operates, heat exchangers must channel large amounts of thermal energy from the firebox into the air stream that flows through the furnace. While exchangers are made of metal alloys designed for this work, they can still crack over time. A common cause of cracks is the presence of moisture on the exchanger.

Dirt

• Exchangers get dirty over time. In air heating units, circulating air keeps many exchangers clean, but if contaminants or dust particles are in the air, layers slowly begin to build up on the exchanger, causing burns and forming deposits. While these may not damage the exchanger, they reduce its effectiveness.

Rust

• If the exchanger encounters moisture regularly, it can start to rust. The water may not cause the exchanger surface to crack, but it allows oxygen to start corroding the metal more quickly. The heat of the exchanger speeds up the process even more until the exchanger stops functioning correctly. Rust may be even more likely if the propane furnace is used to heat water.

Connections

• Heat exchangers are secured by bolts and gaskets. If the heat exchanger is not secured properly, it can lose its connection with other components. Not only can this cause leaks, it also creates noise and reduces the effectiveness of exchanger operation. Even exchangers that are properly installed can vibrate loose over time.