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The Lennox 56M13 is a genuine OEM high-limit switch that protects your Lennox furnace from overheating. It continuously monitors the temperature in the heat exchanger and blower compartment, shutting off the gas valve if temperatures climb beyond a safe threshold. This safety device is built to Lennox factory specifications for the correct temperature rating and reliable response.
Common failure symptoms include a furnace that short cycles, shuts down mid-cycle, fails to fire, or trips repeatedly on the limit. A switch that has opened permanently will prevent heating altogether, while a switch that fails to open removes a critical layer of overheat protection.
Why OEM matters: Limit switches are set to precise trip and reset temperatures matched to your furnace's heat exchanger design. Installing a generic switch with the wrong rating can cause nuisance trips or, worse, allow dangerous overheating. The genuine Lennox 56M13 ensures the exact temperature setpoint your furnace requires, safeguarding the heat exchanger and keeping your equipment warranty intact.