OEM Lennox Flame Sensor Wire — 11M65

The genuine OEM Lennox 11M65 flame sensor wire is the dedicated lead that carries the low-microamp flame-rectification signal from the flame sensor rod back to your furnace control board. This tiny current is how the board confirms the burners have actually lit, allowing it to keep the gas valve open safely. Because the signal is so small, a clean, high-integrity connection is essential to reliable furnace operation.

When the 11M65 wire becomes frayed, heat-damaged, corroded at the terminals, or loose, the board can lose the flame signal and shut the furnace down as a safety measure. Typical symptoms include short-cycling where the burners light then extinguish after a few seconds, repeated ignition lockouts, and flame-sense error codes even after the sensor itself has been cleaned or replaced.

OEM matters because Lennox specifies high-temperature insulation and precise connector terminations rated for the harsh environment near the burner assembly. A generic wire may not withstand the heat or may introduce resistance that weakens the flame signal. This factory replacement restores a solid, correctly rated connection so your Lennox furnace senses flame reliably and runs without nuisance faults.