Lennox 83L89 Limit Switch

The Lennox 83L89 is a factory-specified, auto-reset limit switch engineered for critical temperature regulation in high-efficiency gas furnaces. This OEM furnace safety switch, also identified as Lennox 83L8901, features a precise fixed setpoint with a 145-degree Fahrenheit cut-out temperature and a 115-degree Fahrenheit cut-in temperature. Designed to monitor the internal cabinet or heat exchanger conditions, it serves as a primary safety mechanism that interrupts the heating circuit should temperatures exceed safe operating parameters. The L145-30F configuration ensures the system remains disabled until the unit cools by 30 degrees, at which point it automatically resets for continued operation. Compatible with a wide range of G40, G50, and G60 series units, this replacement limit switch maintains the exact thermal profile required by the manufacturer. Utilizing genuine Lennox 83L8901 components is essential for field service to ensure proper airflow monitoring and to mitigate the risks of excessive heat buildup within the heat exchanger assembly.

• Precise Thermal Protection: Maintains a 145°F trip point to protect the heat exchanger from overheating.
• Automatic Reset Logic: Features an L145-30F 115°F cut-in, resuming operation once the plenum reaches safe temperatures.
• Direct OEM Replacement: Replaces Lennox 83L8901 and equivalent parts from Allied, Armstrong, Concord, and Ducane.
• Durable Construction: Built with a 3-inch element length and steel mounting plate for high-heat environments.

What are the temperature specs for the Lennox 83L89?
The switch is calibrated to open (cut-out) at 145°F and close (cut-in) at 115°F, providing a 30-degree differential.

Is the 83L89 interchangeable with the 83L8901?
Yes, these part numbers are technically identical and serve as direct replacements for the same furnace models.

What causes this limit switch to trip frequently?
Frequent tripping usually indicates restricted airflow, often due to a dirty filter, blocked return air, or a failing blower motor.

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.