The Lennox 28M97 Flame Sensor is a vital OEM replacement part engineered for precise flame rectification in gas-fired furnaces. This furnace flame sensor facilitates a safe ignition sequence by detecting the presence of a burner flame through ionization. If the control board loses the microamp signal, it immediately terminates the gas flow to prevent hazardous accumulation. This sensor is the factory-identical component to 28M9701 and serves as a direct substitute for legacy part numbers including 20467102 and R20467102. Constructed with high-grade Kanthal alloy and high-alumina ceramic insulation, the 28M97 is designed to withstand continuous exposure to 2000°F temperatures. It features a specific 90-degree bend with a 1-1/8 inch reach to the bend and a 1-3/4 inch probe length, ensuring the rod is perfectly positioned within the flame envelope. For technicians servicing Lennox, Armstrong, or Ducane equipment, this heating system sensor is the standard solution for resolving intermittent "no flame" lockouts caused by carbon buildup or cracked ceramics on furnace ignition parts. Key Benefits: Direct OEM Replacement: Fully compatible with Lennox 28M9701, Allied, and Concord systems, ensuring zero-modification installs. Enhanced Safety: High-precision electrode provides the reliable microamp signal required by the furnace control board to prevent gas leaks. Durable Construction: Industrial-grade ceramic insulator prevents electrical shunting to ground in high-heat environments. Standard Connection: Features a 1/4 inch male quick-connect terminal for rapid wiring to the existing harness. Common Questions: How do I know if my 28M97 flame sensor is bad? If the furnace ignites but shuts down after 3–5 seconds, the sensor likely has carbon fouling or a crack in the ceramic. Measure the microamps during the ignition cycle; a reading below 1.0 µA usually indicates a failing sensor. Can I clean the 28M97 instead of replacing it? While light oxidation can be removed with a fine abrasive like emery cloth, deep pitting or visible cracks in the ceramic insulator require a full replacement to ensure consistent signal strength. Is 28M97 compatible with all Lennox furnaces? This sensor fits many G24, G26, and AF80/AF90 series units. Always verify the physical dimensions and the 90-degree "L" shape against your existing probe before installation. Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
