Lennox 20J91 Flame Sensor for Gas Furnaces

The Lennox 20J91 flame sensor is a genuine OEM replacement component designed for Lennox gas furnaces. This critical safety device detects the presence of flame during furnace operation, ensuring safe and reliable heating system performance.

Key Features:

• Genuine Lennox OEM part for guaranteed compatibility and reliability
• Flame rod design detects flame presence through ionization current
• Critical safety component that prevents gas valve from opening without proper ignition
• Direct replacement for worn or failed flame sensors
• Helps restore furnace operation when flame sensing issues occur

The flame sensor is a common maintenance item in gas furnaces. Over time, carbon buildup and oxidation can reduce the sensor's ability to detect flame properly, causing nuisance shutdowns or lockouts. Replacing a faulty flame sensor restores safe, efficient furnace operation and prevents unnecessary service calls.