How to Clean Thermocouple on Water Heater? Signs You Should Never Ignore!

You must be familiar with thermocouples if you own a water heater, but how to clean thermocouple on water heater? You must first understand what a thermocouple is. It is a furnace-connected safety device that detects if the pilot light is on or off. It is immediately attached to the furnace’s gas valve.

How to Clean a Thermocouple on Water Heater

Have you considered cleaning your thermocouple if you need a new one? The thermocouple in your water heater may be rusted and weakened if it isn’t heating up properly.

A thermocouple is a pilot light sensor that regulates the water heater’s temperature. The thermocouple cleaning for water heaters is covered in this section. Even DIY newbies may accomplish the project.

how to clean thermocouple on water heater

Read also: What Is a Thermocouple on a Water Heater?

You’ll need:

  • Adapter wrenches
  • Embroidered cloth sandpaper
  • An anti-lint cloth

5 Steps to Cleaning Thermocouples on Water Heaters

  1. Safety comes first, so the initial step in cleaning a dirty thermocouple on a water heater is to turn off the gas supply. You don’t want any gas flowing while you work. If your water heater is electric, cut the electricity. For gas models, ensure you turn off the gas valve to prevent any gas flow.
  2. Take a photo of the burner assembly before removing the thermocouple so you can remember how it should appear once you’re done. You must unplug the burner assembly from the control center using the wrench. It has three connections (thermocouple, main supply tube, and pilot supply tube). You should be able to move the entire assembly out of its container after those are separated.
  3. The thermocouple should be cleaned by sanding the ends with emery cloth sandpaper and then finishing it with a lint-free cloth. Ideally, you can reach the thermocouple’s ends without removing it from the assembly, but you might need to. If you do, reassemble it precisely as it was initially.
  4. (Optional) Clean the burner. While you have it out, use this chance to scrape any debris off the burner’s top. If you take away the obstructions, they will burn more effectively.
  5. Replace and reconnect the burner assembly. You want everything to have the same appearance when you’re done here. Reconnect the three wires to the control panel on your water heater tank.
  6. Ignite the pilot: After cleaning a thermocouple, turn the dial to the appropriate temperature and open the gas valve. Lighting the pilot would help (we recommend no hotter than 120 degrees F). You should be able to resume operations after that is finished.

Follow these step-by-step instructions to ensure you clean the thermocouple correctly and safely. Remember, if at any point you feel unsure, it’s best to consult a professional.

Bad Thermocouple Symptoms

But before you jump on how to clean the thermocouple on a water heater, you must find out whether the thermocouple is in a bad condition:

  1. The Lights Are On, But They Won’t Stay On.

If the water heater pilot won’t light or doesn’t stay lit, the thermocouple might not be the issue. When starting a standing pilot, the flame should always light first, and then the gas valve is manually held in to keep the flame going and give the thermocouple time to warm up.

Read also: Replacing Thermocouple on Water Heater

When starting a standing pilot, the flame is always lit first, and then the gas valve is manually held in to keep the flame going and give the thermocouple time to warm up. A blockage in the pilot tube is likely to be the cause if you cannot ignite the flame at all while ensuring the gas is on.

There is a thermocouple problem if the flame ignites and then extinguishes when the gas control knob is released after being held in for the necessary 20 to 30 seconds.

Look at the pilot flame before concluding that the thermocouple is to blame. It can be too weak to heat the thermocouple if it is tiny and has an orange-yellow tint. Once more, a blockage in the pilot tube is the most likely cause of the issue.

  1. Try This Before Blaming The Thermocouple

The thermocouple must be heated to the required temperature by the pilot flame for the thermocouple to produce enough voltage to signal the gas valve. The thermocouple probe may be too far away from the flame in some cases, which causes issues.

You can rule out this possibility if you have enough room in your palm to reach and move the probe closer to the flame. By shutting off the gas, removing the pilot tube from the gas valve, and pushing compressed air into the box, you may also rule out clogs in the tube as a potential reason.

Another smart move was to remove the pilot tube and insert a needle into the flame aperture.

  1. Make Sure The Thermocouple Is Working.

Thermocouples for gas appliances have a standard design. In Boise, Baton Rouge, Buffalo, or Boston, a gas water heater uses a thermocouple, which has a probe connected to a copper tube that screws into a port on the gas valve.

When the pilot flame is on, you ought to be able to detect 30 to 40 millivolts of electricity at the connecting end of the tube if the thermocouple is functioning correctly. Using a multimeter, you may do this test on your own.

After cleaning, it’s crucial to test the water heater. Turn on the gas supply and light the pilot. If the pilot light stays lit and the water heater operates normally, you’ve successfully cleaned the thermocouple.

Now you’ve completed the guide and are ready to go. These steps on how to clean thermocouple on water heater will help you with simple problems. However, you must allocate time for your water heater to warm up. Then that’s excellent if it’s functioning! If it still doesn’t work, you might have to spend the money to get a new thermocouple.

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Heater Technician is a skilled author and water heater expert with years of experience in the field. He has authored several articles and books on various aspects of water heater installation, maintenance, and repair.