OEM Lennox Burner Box LB-91798 — 84M22

The genuine OEM Lennox 84M22 burner box, also referenced as LB-91798, is the structural housing that holds and aligns the burners in front of your Lennox gas furnace's heat exchanger. It positions each burner at the correct depth and spacing so the flame enters the exchanger tubes cleanly, supporting stable ignition, quiet operation, and efficient heat transfer.

Common signs of a compromised burner box include rust or corrosion around the burner ports, flames that roll out or lift off the burners, misaligned or loose burners, rumbling on startup, and visible scorching or soot on the housing. A warped or deteriorated box can shift burner alignment enough to trip the rollout safety switch and shut the furnace down.

OEM matters here because the burner box is dimensionally matched to your furnace's manifold, gas valve, and heat exchanger. A generic housing can misposition the flame, leading to incomplete combustion, elevated carbon monoxide, and accelerated exchanger damage. The 84M22 is built to exact Lennox tolerances for a safe, precise fit and factory-rated combustion performance.