Thermocouple installation is the process of replacing the non-functional thermocouple of a pilot light-operated gas heating or hot water system. When a normally functioning thermocouple contacts the pilot light, it energizes a magnet that opens the gas control valve, providing fuel for the heating system to operate.
To install a new thermocouple, the technician turns off the gas supply for safety and removes the unit's outer and inner doors. He disconnects the burner assembly by loosening the pilot and supply tubes, as well as the thermocouple connections. After removing the burner assembly from the combustion chamber, he replaces the old thermocouple with a new one and returns the burner assembly, the pilot and supply tubes and the thermocouple connections. After turning on the gas supply, he checks the new thermocouple by switching on the pilot light and making sure that there is about a half-inch contact between the thermocouple and the pilot light flame. If installation is successful, he closes the doors to the unit.