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Thermocouple Replacement

Step 1: Determine the correct size and style of thermocouple for your water heater. Information, such as your model and serial number can help determine the correct replacement. Most heaters will work with a 24″ universal thermocouple.
Determine correct size of thermocouple

Step 2: Close the gas supply off to the water heater.
Close the gas supply

Step 3: Remove the bottom plate concealing the burner door and slight glass.
Remove bottom plate

Step 4: Disconnect the thermocouple, igniter wire, pilot tubing, and main burner supply.
Disconnect gas connections

Step 5: Disconnect the high limit, or temperature cut-off switch (TCO) wiring.
Disconnect TCO

Step 6: Remove the screws holding the burner door in place. Then slide out the burner.
Remove burner screws

Step 7: Remove the thermocouple from the pilot assembly.
Remove the thermocouple

Step 8: Remove the old push fit adapter and replace it with the new one supplied with the thermocouple. Insert the new thermocouple into the pilot assembly.
Install the new thermocouple

Step 9: Reinstall the burner. Make sure the front of the burner goes into the slot or bracket at the bottom of the burner chamber.
Reinstall the burner

Step 10: Reconnect the main burner, pilot tubing, and thermocouple. Start all connections hand tight to avoid stripping the threads.
Reconnect the main burner

Step 11: Reinstall the burner door and tighten the screws.
Reinstall burner door

Step 12: Reconnect the high limit or temperature cut-off (TCO) wiring.
Reconnect tco wiring

Step 13: Reconnect the igniter wiring.
Reconnect igniter wiring

Step 14: Turn the gas back on to the water heater, then relight the pilot.
Turn water heater gas back on

Step 15: Fire the main burner. Test for gas leaks with a soap solution at the pilot and main burner connections. If you see or smell any gas, turn the gas off, and recheck your connections.
Soap test the joints

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