IMAGE COMING SOON
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 57L26 heat exchanger assembly is the heart of your furnace's heating cycle, absorbing heat from the burner combustion process and transferring it to the supply air while safely venting flue gases away from your indoor air. It is precision-formed to match the burner and blower characteristics of your specific Lennox furnace.
Watch for warning signs of a compromised heat exchanger: hairline cracks or rust flakes, a distorted or yellow burner flame, soot deposits, a strong formaldehyde-like odor during operation, and high carbon monoxide levels. Any of these indicate the assembly should be replaced without delay for safety.
OEM matters here because heat exchangers are safety-critical, combustion-rated components. The Lennox 57L26 is built to the exact metallurgy, dimensions, and pressure tolerances your furnace was certified with — ensuring proper fit, clean combustion, rated efficiency, and full warranty compliance that generic replacements cannot match.