OEM Lennox Flame Sensor — 28M97

The genuine OEM Lennox 28M97 flame sensor is a critical safety and ignition component in your Lennox gas furnace. It uses flame rectification to confirm that a flame is present after the burners light, signaling the control board to keep the gas valve open. Without a working sensor, the furnace cannot safely verify combustion and will shut down as a protective measure.

Common failure symptoms include:

• Furnace lights briefly then shuts off (short cycling on ignition)
• Repeated failed ignition attempts and lockouts
• No heat despite the igniter glowing and gas flowing
• Carbon or oxide buildup on the sensor rod

When a flame sensor becomes coated or degraded, it loses its ability to conduct the tiny microamp signal that proves flame is present, leading to nuisance shutdowns and no heat. Using the genuine OEM Lennox 28M97 ensures the correct rod material, length, and mounting geometry for accurate flame detection and proper microamp readings. Aftermarket substitutes often produce weak or unstable signals that trigger the same lockouts you are trying to fix, so an exact factory replacement protects both furnace reliability and the safety of your Lennox system.