OEM Lennox Heat Exchanger Assembly — 21W93

The genuine OEM Lennox 21W93 heat exchanger assembly is the core component that separates combustion gases from the air circulating through your home. As the burners fire, the 21W93 transfers heat to the airstream while safely venting exhaust, making it one of the most critical safety and efficiency parts in your Lennox gas furnace.

A failing heat exchanger often shows up as visible cracks or rust, a flickering or lifting burner flame, soot buildup, unusual odors, or a furnace that repeatedly shuts down on a tripped limit or flame sensor. Because a compromised exchanger can allow carbon monoxide to enter the supply air, prompt replacement is essential rather than optional.

Choosing OEM matters here more than anywhere else in the furnace. The Lennox 21W93 is engineered to the exact metallurgy, wall thickness, and geometry of your original assembly, ensuring proper flame containment, rated combustion efficiency, and a correct fit against the burner box and collector. Aftermarket substitutes can shift heat distribution and void your Lennox warranty. Install this authentic OEM assembly to restore safe, reliable, factory-rated performance.