52W29 Furnace Flame Sensor Replacement - For Lennox Armstrong & Ducane Furnaces

52W29 Furnace Flame Sensor

Key Features

• Monitors burner flame to ensure safe furnace operation.
• Direct replacement for the original manufacturer's part.
• Overall length: 5.25 inches.
• Sensing rod length: 2.75 inches.
• Constructed with a high-temperature resistant metal rod and ceramic insulator.

Replaces / Cross-Reference Part Numbers

• 52W29
• 52W2901
• 31L71
• 31L7101
• LB-74940A
• 28PV41
• 903600
• FLS52W29

Compatibility & Fitment

• Fits specific gas furnace models from Lennox, Armstrong, and Ducane.
• Compatible with furnace series including G40, G41, G50, G51, G60, G61, and G71.

When to Replace

• Furnace ignites but shuts down after a few seconds.
• Furnace fails to heat consistently or at all.
• The sensor rod is visibly corroded, cracked, or has heavy carbon buildup that cannot be cleaned.

Installation Tips

• Disconnect all electrical power to the furnace before servicing.
• Handle the component by its metal bracket to avoid damaging the ceramic insulator.
• Ensure the sensor rod is properly positioned in the flame path for correct operation.
• Verify a secure wire connection before restoring power.