OEM Lennox Heat Exchanger Assembly — 28M85

The genuine OEM Lennox 28M85 heat exchanger assembly moves combustion heat into your home's air stream while keeping flue gases fully separated from the air you breathe. As the heart of a Lennox gas furnace's heating cycle, it channels hot products of combustion through sealed passages while the circulating blower delivers clean, warmed air throughout your ductwork. Every dimension and material is built to Lennox factory specification.

Watch for warning signs that the exchanger has failed: hairline cracks or corrosion on the metal, a burner flame that flickers or rolls out, black soot deposits, loud pops or rumbles at start-up, or a lingering acrid smell during operation. Since a breached exchanger can allow carbon monoxide into your living space, these symptoms call for immediate attention.

Installing the OEM 28M85 protects the safety and efficiency your Lennox furnace was engineered to deliver. Lennox selects the exact alloy, wall thickness, and weld construction needed to survive the thermal stress of repeated heating cycles — qualities aftermarket copies frequently miss. This authentic replacement ensures a precise fit, preserves your warranty, and returns your system to rated performance.