OEM Lennox Heat Exchanger Kit — 15U79

The genuine OEM Lennox 15U79 heat exchanger kit provides the complete assembly and associated hardware needed to restore safe, efficient heat transfer in your Lennox gas furnace. The 15U79 kit takes combustion heat from the burners and passes it into the circulating air while keeping exhaust gases sealed off from the supply stream, making it essential to both furnace performance and home safety.

Typical indicators that this kit is required include visible cracks or corrosion on the exchanger, a burner flame that flutters or lifts when the blower runs, soot deposits, odd odors during heating, or a furnace that repeatedly cycles off on its limit switch. A cracked heat exchanger poses a carbon monoxide risk and calls for prompt replacement.

OEM matters because the Lennox 15U79 kit is engineered with the correct materials, gaskets, and geometry to fit your furnace exactly, ensuring proper combustion sealing, rated efficiency, and warranty compliance. Because it ships as a kit, you get the matched components for a clean, complete installation rather than piecing together aftermarket parts. Choose this authentic OEM kit for safe, factory-spec furnace operation.