L210-20F Furnace Primary Limit Switch (-40°F to 180°F) - For ICP Heil Tempstar Furnaces Thermal Fuse primarily "Vertical Modular Washer" models

primarily "Vertical Modular Washer" models manufactured from 2009 to present

and one washer

The cycling thermostat is typically located on the blower wheel housing

The bulb is flickering

L210-20F Furnace Primary Limit Switch (-40°F to 180°F) - For ICP Heil Tempstar Furnaces Thermal Fuse primarily "Vertical Modular Washer" modelsL210 20F Primary Furnace Limit Switch Key Features Critical safety switch designed to shut down the gas valve and burner circuit if the furnace heat exchanger exceeds maximum safe operating temperatures. Thermal setting calibrated to automatically open the circuit on temperature rise at 210F and close (reset) at 190F. Constructed with a highly responsive bimetallic disc enclosed in a temperature resistant phenolic housing to prevent heat distortion.