OEM Lennox Secondary Heat Exchanger Assembly — 80M49

The genuine OEM Lennox 80M49 is a secondary heat exchanger assembly designed for high-efficiency condensing furnaces. In a condensing furnace, the secondary heat exchanger extracts additional heat from the combustion flue gases after they leave the primary exchanger, condensing water vapor and boosting overall efficiency. Precise fit to your Lennox furnace ensures proper combustion sealing and rated AFUE performance.

Common failure symptoms: When a secondary heat exchanger corrodes, cracks, or clogs, you may notice reduced heating output, short cycling, a lockout on the furnace control, water leaking around the unit, or the appearance of soot and condensate. A compromised heat exchanger can also allow flue gases to escape, which is a serious carbon monoxide safety concern that warrants immediate replacement.

Why OEM matters: Heat exchangers are safety-critical, factory-matched components. Only a genuine Lennox 80M49 guarantees the correct alloy, coil geometry, and gasket interfaces required to seal against combustion byproducts and maintain your warranty. Aftermarket substitutes risk improper fit, premature corrosion, and unsafe flue conditions in your Lennox equipment.