Lennox 27J02 Flame Sensor

The Lennox 27J02 Flame Sensor is a critical OEM replacement part designed for precision flame monitoring in high-efficiency Lennox gas furnaces, including the G26 series. This straight-style furnace flame sensor features a 13/16-inch rod and a 20-1/2 inch lead with a female spade connector, ensuring seamless integration with the ignition control board. Since the 27J02 is identical to 27J0201, it serves as a direct drop-in for units requiring 24 VAC flame rectification. As a veteran tech knows, a fouled or oxidized sensor is the primary cause of furnace short cycling or no flame detection error codes. By maintaining a clear microamp signal, this flame rod prevents the gas valve from staying open during ignition failure, protecting the heat exchanger and ensuring safe combustion. Whether for Allied, Armstrong, or Ducane branded equipment, this sensor is the standard for restoring reliable heating system performance.

• Direct OEM Compatibility: Verified as 100% interchangeable with part number 27J0201 for Lennox and Allied brands.
• Precise Flame Sensing: Provides accurate microamp current feedback to the control board to prevent nuisance lockouts.
• Durable Construction: High-grade ceramic insulator prevents electrical leakage and grounding issues during the ignition sequence.
• Plug-and-Play Installation: Includes the 20" lead and standard spade terminal for fast field replacement.

What are the signs of a bad Lennox 27J02 flame sensor?
Common symptoms include the furnace burners igniting for 2-5 seconds and then immediately shutting off, or the control board flashing a "low flame signal" error code.

Can I clean the 27J02 instead of replacing it?
While cleaning with a mild abrasive can remove carbon buildup temporarily, a sensor with a cracked ceramic insulator or deep pitting must be replaced to ensure system reliability.

Will this work with Armstrong or Ducane furnaces?
Yes, because Lennox is the parent company for Allied Air brands, the 27J02 is frequently specified for Armstrong, Concord, and Ducane models using the same ignition system.

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.