OEM Lennox Inshot Burner Assembly (2-Pack) — 18L51

The genuine OEM Lennox 18L51 (also identified as part 619795-02) is a set of two inshot burners used in Lennox gas furnaces. Inshot burners deliver and shape the gas-air mixture as it fires into each tube of the heat exchanger, producing the clean, even flame that transfers heat to your home's air. Each burner is precisely formed so the flame lights reliably from the igniter and carries smoothly across all burners, keeping combustion stable and efficient.

Common failure symptoms: Burners that have corroded, cracked, or become clogged with rust and debris can cause hard or delayed ignition, flame roll-out, a yellow or lazy flame instead of crisp blue, noisy or popping startup, and short-cycling on the flame sensor or limit control. Damaged burners can also produce incomplete combustion and soot, which is both an efficiency and a safety concern.

Why OEM matters: Inshot burner port sizing, orientation, and venturi geometry are engineered to match the furnace's gas orifices, igniter, and heat exchanger. Installing the genuine Lennox 18L51 ensures correct flame carryover, proper combustion, and rated efficiency across the burner set. Aftermarket burners can misfire or burn improperly, so use the OEM assembly to keep your Lennox furnace running safely.