Lennox 83L72 Flame Sensor for Gas Furnaces

The Lennox 83L72 Flame Sensor is a genuine OEM-replacement component designed to maintain safe and efficient operation in compatible Lennox gas furnace systems. The flame sensor plays a critical role in your furnace’s safety circuit — it detects the presence of a burner flame and signals the control board to keep the gas valve open. If the sensor fails or becomes coated with oxidation, the furnace will shut down as a safety precaution, leading to no-heat calls and repeated lockouts.

Key Features

• Direct OEM replacement for compatible Lennox gas furnace models
• Ensures accurate flame detection for reliable burner operation
• Helps prevent nuisance shutdowns caused by a faulty or degraded sensor
• Restores proper communication between the burner and furnace control board
• Durable construction for long-lasting performance in demanding HVAC environments

Why Replace Your Flame Sensor?

Over time, flame sensors accumulate a thin layer of oxidation on the sensing rod, which reduces electrical conductivity and causes the furnace to misread or fail to detect the flame. Replacing the sensor with a genuine Lennox part like the 83L72 restores accurate signal transmission and eliminates unnecessary service calls.

Application

• Designed for use in compatible Lennox gas furnace systems
• Consult your equipment’s service manual or parts list to confirm compatibility before installation

Installation Notes

• Always disconnect power before servicing the furnace
• Lightly clean the sensing rod with fine steel wool or emery cloth if reusing an existing sensor
• Ensure proper mounting and secure electrical connection upon installation