How to Replace the Thermocouple on a Hot Water Heater

Having trouble keeping the pilot light on your gas hot water heater lit? More often than not, when the pilot light on a gas hot water heater will not stay lit, it is because of a defective thermocouple, which is a device that will turn off the gas should the pilot light ever go out. It is a piece of tubing that connects the pilot on the hot water heater to the gas controller.

Sometimes, the problem can be some sort of blockage within that the small tube that provides the pilot with gas. If this is the case, the blockage can be cleared by blowing air into it or using a very thin piece of wire.

Ultimately, though, if your pilot light on the water heater will not remain lit, the thermocouple is the culprit. If so, it will need to be replaced. Luckily, they aren’t expensive and you can usually find one for under $10. What’s even better is that the thermocouple is incredibly simple to install. Here’s how:

  1. You want to first turn the gas supply off at the gas controller. Double-check to make sure it is off before you proceed.
  2. Along with two small gas tubes, the thermocouple is held on to the valve by three nuts, which need to be unfastened. The burner will need to be slid out of the burning chamber.
  3. The thermocouple now needs to be removed from the burner. Take it with you to buy the new one to make sure you get the right one. Generally, the thermocouple is attached with a clip (or several) to the gas supply tube. The end of it can be pulled out of the pilot assembly.
  4. In the exact same way that you removed the defective thermocouple, you need to install the replacement thermocouple. Make sure every piece is reconnected properly.
  5. Turn the gas supply back on. Light the water heater following instructions. Use soapy water on the joints to test for gas leaks.

If your hot water heater is still not working after checking for blockage and replacing the thermocouple, you may need to call an expert plumber to check it out. Available 24/7 and for emergency calls, the local experts at Rooter-Man are skillfully trained and experienced in all plumbing problems, can easily determine the culprit of your plumbing problem, and provide a reasonably priced solution. If you need a new hot water heater, Rooter-Man can install the most suitable energy-efficient hot water heater for your home.