Laars Heating Systems 2400 058 Limit Switch 320734 701 this kit provides the precise this kit provides the precise tolerances required to prevent chatter and ensure reliable cycling under varying thermal loads Speed is typically increased by closing the adjustable halves (increasing the effective diameter) or decreased by opening them Automated Operation: The automatic reset limit switch eliminates the need for manual intervention after a temporary high temperature event once the system cools It will automatically close the circuit and allow the burner to fire again once the sensor detects the temperature has fallen back to the 140°F cut in level