OEM Lennox Secondary Heat Exchanger Assembly — 80M48

The genuine OEM Lennox 80M48 secondary heat exchanger assembly is a critical component in high-efficiency condensing gas furnaces. In a 90%+ AFUE Lennox furnace, the secondary heat exchanger extracts additional heat from the flue gases after they leave the primary exchanger, condensing water vapor to capture latent heat and dramatically improve fuel efficiency. This assembly is engineered to the exact specifications required for safe, reliable operation of your Lennox system.

Common failure symptoms: A failing secondary heat exchanger often reveals itself through visible corrosion or rust, cracks or perforations that trigger flame rollout or pressure-switch faults, water leakage inside the furnace cabinet, soot buildup, or a persistent flame-sensor or ignition lockout. Because a compromised heat exchanger can allow carbon monoxide into the airstream, replacement should never be delayed.

Why OEM matters: Lennox condensing furnaces route flue gases through precisely designed passages, and aftermarket exchangers rarely match the fin geometry, alloy, and drainage angles required. The OEM 80M48 guarantees correct fit, proper condensate drainage, and factory-rated efficiency and safety margins — protecting both your warranty and your household. Installation should be performed by a qualified HVAC technician.