Caution: Please read our safety information before attempting any maintenance, installation or repair.

The thermocouple is a safety feature that determines if the pilot light is lit. The heat of the pilot light flame creates millivolt current in the thermocouple which energizes a magnet that in turn allows the gas control valve to operate. If the pilot light goes out, the thermocouple will not allow the gas valve to operate.

A common symptom of a faulty thermocouple is the pilot light will not stay lit. Check that the thermocouple connection to the gas valve is tight and the other end of the thermocouple is properly positioned in or near the pilot light flame. If it appears properly installed then it may ned to be replaced.

1. Turn off the gas supply to water heater.
2. Remove outer and inner doors.
3. Disconnect the burner assembly from the gas control by loosening the pilot tube, supply tube and thermocouple connections.
4. Remove burner assembly from the combustion chamber.
5. Remove the old thermocouple from the bracket. It may be held in place with tension or a screw. Loosen the screw, if any, and pull firmly and twist the thermocouple from the bracket.
6. Install the new thermocouple. Position the thermocouple tip so that the pilot flame heats the top 1/2 inch of the tip.
7. Replace burner assembly in combustion chamber.
8. Tighten the main burner supply tube, pilot supply tube and thermocouple connection to the gas control valve. Turn the thermocouple no more than one quarter turn beyond hand tight.
9. Turn on the gas supply
10. Check main supply tube and pilot supply tube at the gas control valve for gas leaks with a soap and water solution. Bubbles indicate a leak. Tighten all connections if a leak is found.
11. Light the pilot light.
12. Check that 1/2 inch of the thermocouple tip is positioned in the flame.
13. Replace inner and outer doors.