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How To Clean The Thermocouple On Water Heater?

By March 1, 2023Plumbing
Be sure to turn the gas line off before cleaning the thermocouple.

Maintenance of your home is not often thought of as something like a water heater. Unfortunately, most homeowners only look at what is in front of them for maintenance. For example, maintaining their yard, or appliances that are used daily. Consequently, if you ever want your water heater to last as long as the manufacturer states, you will need to conduct proper maintenance. There are important parts of a water heater that need to be cleaned in order to sustain functionality. The thermocouple is one of those parts. Curious as to how to clean the thermocouple on the water heater? You will have to shut down the power supply and then work carefully to remove the unit.

Let’s take a look below at some specifics regarding a thermocouple.

What Is A Thermocouple?

Believe it or not, a thermocouple is a small unit that is located near the bottom of a gas water heater. They control the amount of gas that can flow through to keep the water heater functioning properly. The thermocouple will heat the necessary amount of hot water needed for your home.

Thermocouples send electric currents to the pilot light so that the light stays lit. To keep it working properly and heating your water it must be cleaned or replaced. You don’t want to allow it to corrode and stop functioning. This could become a dangerous situation.

The pilot light on the inside of a working gas water heater.

How To Clean The Thermocouple On Water Heater – Steps

Cleaning a thermocouple can be done by a homeowner. However, when you are working on maintaining your water heater, it is likely a better idea to hire a master plumber. Let’s take a look below at how we can clean the thermocouple.

  1. Turn off the gas inlet valve – It is imperative that you shut off the gas supply line to protect yourself while working on the water heater. If you are working on an electric water heater, then simply turn the circuit breaker off to cut the power source.
  2. Remove the burner assembly – Anytime you are working on a new project you should take a picture of how it is originally set up. This allows you to refer back to it once you’re done. Use a wrench and disconnect the burner assembly from the control center. This disconnect occurs in three places. The thermocouple, the main supply tube, and the pilot supply tube. As soon as you have disconnected these parts, you can slide the burner assembly out.
  3. Clean the thermocouple – Using an emery cloth sandpaper you will sand down the ends of the thermocouple. It is possible to remove it completely from the assembly, but might not be necessary. Be sure to reinstall it the exact way you removed it.
  4. Replace and reconnect the burner assembly – Review the picture that you took so that you can replace the assembly in the exact way that you removed it. Reconnect all three lines back to the control center on your water heater.
  5. Light the pilot light – Open the gas valve inlet if you have a gas heater and relight the pilot light. Make sure that the ideal is turned to no hotter than 120 degrees Fahrenheit.

Other Recommended Maintenance

Now that you are ready to clean your thermocouple, this would be a great time to also learn about how to reset your electric water heater. In some cases, the thermostat might go bad, or something else trips the breaker. Use the red reset button to begin troubleshooting.

Next, be sure to read up on if your gas water heater needs electricity. In some parts of your gas water heater, electricity is likely needed. Knowing this ahead of time will save you a lot of stress when the power goes out.

Lastly, read up on how long it takes a water heater to heat up the water. Once you have reset the water heater it will take some time to heat up the water. Depending on the size of your heater and the distance it is from your main pipes determines how long it will take before you feel hot water again.

Repairing or cleaning a thermocouple should be done by a professional.

When Do I Call A Professional?

When dealing with a water heater it is recommended that you hire a master plumber. They have the experience and knowledge of how to clean your thermocouple without causing damage to your unit. If you aren’t sure who to call, reach out to your local home inspection team. They can come out and inspect your plumbing and ensure that your water heater is properly maintained.


Understanding how to clean thermocouples and maintain various parts of your water heater for maintenance purposes is key. Most homeowners will install a water heater and just forget about it. Not realizing that a water heater requires some very precise maintenance. If you want to determine how old your water heater is and when you should conduct the proper maintenance call your local home inspection team. Reach out to Alpha Building Inspectors who can check your water heater during a home inspection in the Merrimack, New Hampshire area.