OEM Lennox Limit Switch — 36K14

The genuine OEM Lennox 36K14 limit switch is a critical safety control in your Lennox gas furnace. It continuously monitors the temperature inside the heat exchanger and blower compartment, shutting down the burners if the unit exceeds its safe operating temperature. This protects the heat exchanger from cracking and prevents dangerous overheating conditions, making it one of the most important safety components in your system.

When the 36K14 fails or drifts out of calibration, you may notice the furnace short-cycling, the burners igniting then quickly shutting off, no heat output, or the blower running continuously. A failed limit switch will often lock the furnace out entirely to prevent unsafe operation.

Choosing an OEM Lennox part matters because the 36K14 is calibrated to the exact trip temperature and mounting specifications your Lennox furnace was engineered around. Aftermarket substitutes with incorrect temperature ratings can allow overheating or cause nuisance shutdowns. Installing the factory-specified switch ensures proper fit, accurate safety response, and reliable heating performance for your Lennox equipment.