OEM Lennox Ignitor & Flame Sensor Assembly — 84K65

The genuine OEM Lennox 84K65 ignitor and flame sensor assembly handles two essential jobs in your Lennox furnace: the hot surface igniter glows to light the burners on a call for heat, while the integrated flame sensor confirms a stable flame is present so the control board keeps the gas valve open. Together they ensure reliable, safe ignition every cycle.

Common failure symptoms: A worn 84K65 assembly typically causes no-heat calls, burners that fail to light, or a furnace that ignites and then shuts down after a few seconds (flame-sensing failure). Cracked or crumbling igniter elements, a carbon-fouled flame rod, or repeated ignition lockouts on the control board all point to this assembly.

Why OEM matters: Hot surface igniters are brittle and highly sensitive to voltage, resistance, and precise positioning within the burner flame. The factory 84K65 is built to Lennox specifications for correct glow temperature, flame-rod placement, and warm-up timing — ensuring dependable ignition and accurate flame verification. Generic igniters often fail early or mis-sense flame, causing frustrating intermittent no-heat calls and potential warranty issues.