Step 5 · Replace the Thermocouple

This is the step most people slow down on. Take it one move at a time — there’s no rush, and you can rewind the clip as many times as you need.

If cleaning the thermocouple does not solve the issue, it needs to be replaced. Ensure the gas is off. Using two wrenches (one to hold the valve body, one to turn the nut), carefully disconnect the thermocouple's copper lead from the bottom of the gas control valve. Note how it connects. Then, disconnect the other end from its mounting bracket in the burner assembly. Take the old thermocouple with you to a hardware or plumbing supply store to get an exact replacement (they vary in length). Install the new one by reversing the removal process. Hand-tighten the nuts first, then give them a final quarter-turn with a wrench. Do not overtighten.