OEM Lennox Limit Switch — 87H92

The genuine OEM Lennox 87H92 limit switch is a temperature-sensing safety control that protects your Lennox furnace from overheating. Mounted near the heat exchanger or plenum, it monitors supply-air temperature and opens the circuit to shut down the burners if the furnace gets too hot — usually the result of restricted airflow.

When the 87H92 trips or fails, you may experience short-cycling, a furnace that shuts off on high heat, no heat with a limit-fault error, or a blower that runs continuously. While a dirty filter, closed vents, or a failing blower motor often cause a limit to trip, the switch itself can also weaken or fail open over time and require replacement.

OEM matters because the 87H92 is calibrated to the precise open and close temperatures your specific Lennox model requires. A generic limit with the wrong setpoint can allow dangerous overheating or cause repeated nuisance shutdowns. This factory replacement restores proper overheat protection and reliable furnace operation.