OEM Lennox Inshot Burner — 27K66 (65257000)

The genuine OEM Lennox 27K66 inshot burner (Lennox reference 65257000) injects the metered gas-air mixture into the heat exchanger and shapes the flame for efficient, complete combustion in your Lennox gas furnace. Each inshot burner is precisely ported so the flame ignites smoothly, carries evenly across the heat exchanger, and delivers reliable warmth throughout the heating season.

Over time, burner ports can clog with dust and corrosion or become misaligned, producing symptoms like hard or delayed ignition, a rumbling or popping sound at startup, a yellow or unstable flame, flame rollout, or recurring ignition-lockout faults. Because these issues affect both efficiency and safety, a worn or fouled burner should be replaced rather than repeatedly cleaned.

Fitting the OEM Lennox 27K66 burner guarantees the correct port geometry and orifice alignment Lennox engineered for this furnace, ensuring the flame seats properly in the heat exchanger and works in harmony with the gas valve and ignition controls. Aftermarket burners often flame differently and can trigger nuisance shutdowns or sooting. This factory-specified part restores clean, dependable combustion and preserves the performance of your Lennox system.