OEM Lennox Heat Exchanger Assembly — 33M10

The genuine OEM Lennox 33M10 heat exchanger assembly is the heart of your furnace's heating cycle, transferring combustion heat into the air distributed through your home while safely isolating and venting flue gases. In your Lennox system, the 33M10 directly governs both heating efficiency and the safety of the air you breathe.

Signs that this assembly needs to be replaced include visible cracks, rust or scaling on the metal, a burner flame that flickers, changes color, or rolls out when the blower engages, soot buildup, unusual odors, or frequent shutdowns caused by a tripped high-limit switch. Any cracked heat exchanger creates a carbon monoxide hazard and should be addressed immediately.

OEM is non-negotiable for this part. The Lennox 33M10 is manufactured to the precise alloy, wall thickness, and dimensional specs of your original component, ensuring proper flame containment, correct draft, rated combustion efficiency, and a leak-free fit to the burner box and collector. Aftermarket versions can alter heat distribution and void your Lennox warranty. Install this authentic OEM assembly to bring your furnace back to safe, factory-rated performance.