How to Replace a Water Heater Thermocouple

A bad thermocouple is a very common problem for a water heater.

Replace a Water Heater ThermocoupleReplace a Water Heater Thermocouple
A thermocouple is what keeps the pilot flame lit. If the thermocouple goes bad, the pilot light will go out and you will have no hot water. Learning how to replace it will save you time and money.

Turn the gas shut off valve to the closed position. The shut off handle will be perpendicular to the pipe. Remove the cover from the burner area.

Use a crescent wrench to unthread the pilot, thermocouple, and main gas connections from the gas valve.

Remove burner panel, if it's a spark ignitor then you will probably have to remove four screws, like on this one. On non-spark models the panel just slides out.

With the panel removed, you can take out the whole burner assembly.

The thermocouple either slides out or is threaded out. You may need to tap it out with the end of your wrench if you are having trouble with a slide out thermocouple. A universal kit will cover all you bases, it's not a bad idea to order a couple and keep some on hand.

Slide burner assembly back in and reconnect pilot gas, main gas, and thermocouple. Relight the pilot.

Things You Will Need

  • Thermocouple
  • Crescent wrench
  • Screwdriver


  • Don't forget to shut off gas.
  • If your water heater is power vented, unplug the power cord.


  • Thermocouple may be hot to the touch.

About the Author

This article was created by a professional writer and edited by experienced copy editors, both qualified members of the Demand Media Studios community. All articles go through an editorial process that includes subject matter guidelines, plagiarism review, fact-checking, and other steps in an effort to provide reliable information.