OEM Lennox Ignitor & Flame Sensor Assembly — 13H25

The genuine OEM Lennox 13H25 ignitor and flame sensor assembly is responsible for lighting the burners and confirming flame presence on every heating cycle of your Lennox furnace. The hot surface ignitor heats up to ignite the gas, while the flame sensor detects the resulting flame and tells the control board it's safe to continue supplying fuel.

Common failure symptoms: When the 13H25 goes bad, you'll often see no heat, a furnace that attempts ignition but never fires, or short cycling where the burner lights briefly and then shuts down because flame isn't confirmed. Hot surface ignitors are brittle and wear out with repeated heating, and flame sensors can foul or corrode over time.

Why OEM matters: The 13H25 is engineered to your furnace's exact resistance spec, mounting position, and ignition timing. Installing the factory Lennox part ensures consistent, reliable ignition and accurate flame sensing without nuisance lockouts. Lower-cost universal ignitors frequently fail early or trigger false flame faults.