Step1: Disconnect electrical power and shut off the gas supply to the appliance before servicing.
Step2: Allow the equipment to cool completely and remove the access panel.
Step3: Label and disconnect the wires from the existing hi-limit thermostat.
Step4: Carefully remove the sensing bulb and mounting hardware from the old thermostat.
Step5: Install the new thermostat and secure the nickel sensing bulb in its original location.
Step6: Reconnect the wiring to the appropriate terminals and verify all connections are tight.
Step7: Reinstall the access panel, restore power, and test the manual-reset hi-limit safety function for proper operation.