Lennox Ducane Flame Sensor 69W43 Original Part

Lennox Flame Sensor 69W43 | Genuine OEM Replacement

Ensure your furnace operates safely and reliably with the Lennox 69W43 Flame Sensor. This Genuine OEM Factory Authorized Part is a critical safety component designed to detect the presence of a flame during the ignition cycle, preventing the accumulation of unburned gas in Lennox, Armstrong, and Ducane furnaces.

Technical Specifications

• Part Number: 69W43
• Construction: High-temperature resistant ceramic insulator and high-grade metal rod for accurate microamp signal transmission.
• Type: Furnace Flame Sensor (Flame Rod)

Direct Replacement & Compatibility

The 69W43 is the authorized direct replacement for several older Lennox and Allied Air part numbers. Choosing a Factory Original part ensures the mounting bracket and rod geometry align perfectly with your existing burner assembly, providing the precise positioning required for a consistent flame signal.

• Replaces Part Numbers: LB-74940B, 102431-02, 10243102, PSE-L79
• Equipment Brands: Lennox, Armstrong, and Ducane.
• Application: Used in a wide variety of residential gas furnace models.

Why Choose Genuine Lennox OEM?

The flame sensor is one of the most common points of failure in a furnace. Over time, sensors can become oxidized or the ceramic can crack, leading to "nuisance" shutdowns where the furnace ignites and then immediately turns off. Genuine Lennox sensors are manufactured to exact tolerances to ensure they send a clear, steady microamp signal back to the control board, preventing unnecessary service calls and ensuring your home stays warm.

Shipping Information

• Service Area: Shipping rates apply to the continental United States only.

Pro-Tech Maintenance & Troubleshooting Tip: If your furnace shuts down within a few seconds of ignition, a dirty or faulty flame sensor is often the culprit.

• Cleaning: Before replacing the sensor, you can attempt to clean it by gently rubbing the metal rod with a very fine abrasive (like a Scotch-Brite pad or fine steel wool) to remove carbon buildup. Avoid using sandpaper, as it can leave silica residue that may damage the sensor.
• Mounting: When installing the new 69W43 sensor, ensure the metal rod is positioned directly in the path of the burner flame. Verify the ceramic insulator is not cracked and that the wire connection is tight and free of corrosion.