How to Clean a Thermocouple Water Heater

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Since it is a crucial part of its maintenance, cleaning a thermocouple water heater is indispensable. Failure to do it leads to complications eventually. If you want to avoid them, let’s see how to clean a thermocouple water heater quickly and correctly.

How to Clean a Thermocouple Water Heater

When a water heater doesn’t work properly, it doesn’t mean you need to buy a new one. One of the probable causes could be a compromised and dirty thermocouple. Usage over time leads to calcite deposits that lead to malfunction. Therefore, it needs to be cleaned.

Gather The Required Tools

  • Adjustable wrench
  • Emery cloth, sandpaper, abrasive sponge, or steel wool
  • Lint-free cloth such as microfiber

Method #1: How to Clean a Thermocouple Water Heater (Electric)

Step #1: Turn Off Power

This is more of a way to take precautions. You don’t want to experience an electric shock hence the need to turn off the power.

Pipes of a water heater

Step #2: Identify Its Thermocouple

The thermocouple is easy to notice since it is either a thin wire or metal tubing. It is not far from the pilot light tube.

Step #3: Loosen the Thermocouple

Upon identifying it, you will have to loosen it before cleaning. The tool you need depends on the model of your water heater. It can either be a screwdriver or a wrench.

Step #4: Clean It

Start scrubbing the build-up or corrosion. Use the likes of abrasive sponge, steel wool, or emery cloth but ensure that you scrub gently.

Ensure that you don’t overlook the threading of its screws connecting the thermocouple to the water heater. Equally important, apply pressure evenly.

Avoid using a flammable cleaning product.

Step #5: Wipe the Thermocouple

Scrubbing may still leave excess particles, which is where a lint-free cloth comes in. Use a microfiber cloth to clean the thermocouple and remove such particles.

Step #6: Reattach the Thermocouple

Once it is sparkling clean, could you return it to its original place? It is not hard as you only need to follow these steps:

  • Slide it into the metal bracket, so it fits correctly. 
  • Once in place, tighten it.
  • At first, use your bare hands to turn its nuts as a precaution of avoiding stripping them.
  • Finally, tighten it using a wrench and ensure that you don’t apply much pressure while at it.

Step #7: Turn the Water Heater Back On

Now your water heater is ready to work perfectly because the thermocouple is clean.

Method #2: How To Clean A Thermocouple Water Heater (Gas)

The procedure to clean a gas water heater is slightly different from an electric one, given the other components.  

Step #1: Shut the Gas Inlet Valve

Whereas you cut electricity power in the previous type, this one requires you to turn off its gas valve. Again, this step is for the sake of your safety.

Step #2: Disconnect Burner Assembly

Use a wrench to disconnect the control center and the burner assembly. 

You will be disconnecting it from the pilot supply tube, main supply tube, and thermocouple.

Step #3: Remove the Thermocouple

Slide the entire burner assembly out, including the thermocouple. The following two steps are similar to that of the previous method since we are cleaning the same components.

Step #4: Clean It

Same as before, scrub and clean any build-up or corrosion. 

As the build-up is likely to be sticky and tough, it’s best to use materials like an abrasive sponge, steel wool, or emery cloth. 

But remember to be gentle with it and apply equal pressure throughout. 

Avoid using any flammable cleaning product.

Step #5: Wipe the Thermocouple

For wiping the thermocouple, use a lint-free cloth to remove all the excess particles left after scrubbing. You can preferably use a microfiber cloth to clean for this step.

Step #6: Clean the Burner

It is also an ideal time to clean your burner so that it can start burning efficiently.

Step #7: Reconnect the Assembly

Once you are done cleaning, return every piece of the system to its respective places.

Step #8: Open the Gas Valve

Open the water heater gas valve to supply it with fuel.

Step #9: Light It

Go ahead and light the pilot. Your heater should work excellently.

Here’s a video guide about how to clean a gas thermocouple water heater.

Frequently Asked Questions

What Are the Symptoms of a Bad Thermocouple?

The symptom is the pilot light not staying on. However, don’t mistake it with a case of its obstruction.

If you are dealing with an obstruction, the pilot light doesn’t go on even though the gas is on. You can check few instances of the pilot outage and troubleshooting solutions here

Multiple heater with multiple showers

What Causes a Thermocouple to Fail?

By design, thermocouples quickly respond to temperature changes by expanding or contracting depending on whether they are high or low.

If these changes happen too often, it becomes weak. As the rapid changes continue, the thermocouple breaks, failing eventually.

Is a Thermocouple Different From an RTD?

Both the Resistance Temperature Detector (RTDs) and thermocouples serve the same purpose. However, the latter responds faster than the former. 

As for the principle, RTDs use resistance for the electricity flow.


If you’re having issues with your water heater, cleaning its thermocouple could make all the difference. This could even lessen your time to clean so much in the house.

Make sure that you use the right procedure to get great results. Also check out for the things beyond it, such as nails. Otherwise, it will be a waste of time, money, and resources.