OEM Lennox Furnace Limit Switch — 11G55

The genuine OEM Lennox 11G55 limit switch protects your furnace by monitoring temperature inside the heat exchanger and plenum, cutting power to the burners if heat rises above the safe operating limit. It works with the blower control circuit to manage fan timing, ensuring the furnace delivers warm air efficiently while guarding against dangerous overheating. Each switch is set to the specific trip and reset temperatures Lennox specifies for the equipment it supports.

Symptoms of a failing limit switch include a furnace that overheats and locks out, repeated short-cycling of the burners, a blower motor that runs nonstop or fails to engage, and intermittent or total loss of heat. A switch that has drifted out of calibration or become stuck can trigger nuisance shutdowns or leave the system without proper overheat protection.

Choosing the OEM Lennox 11G55 matters because its temperature thresholds are matched to your furnace's design and airflow. A generic replacement with different setpoints may trip prematurely, fail to open when it should, or undermine the safety circuit. The factory part ensures accurate calibration, a precise fit, and dependable compatibility with your Lennox system.