Flame Sensor fits Lennox Furnace, 18G8901, 18G89

Furnace Flame Sensor | ERP | Replaces Lennox® 18G89

Brand new Exact Replacement Parts furnace flame sensor replacing Lennox part number 18G89. This sensor detects the presence of a flame and sends a confirmation signal to the furnace control board to ensure safe ignition and continued burner operation.

A worn or contaminated flame sensor can cause ignition failure, short cycling, or the furnace shutting down shortly after startup. Replacing the sensor restores reliable flame detection and safe heating performance.

⚙️ Features & Specifications

• Total Length: 3-1/8 inches
• Accurately detects burner flame presence
• Ensures safe ignition and sustained burner operation
• OEM‑style fit for Lennox furnaces
• Condition: Brand New – Unused

⚠️ Symptoms This Part Fixes

• Furnace starts then shuts down
• Ignition failure or intermittent heating
• Short cycling
• Flame not detected by control board

Replaces Part Numbers

18G8901

Compatible Furnace Models

G11E, G12E, G16, G16RG17, G17RG20, G20R, G23GSC10, LD20, LF20, 78RGF

Restore reliable ignition and safe heating performance with this OEM‑compatible Lennox flame sensor — accurate, durable, and ready for installation.