How to Clean the Thermocouple on a Water Heater

A thermocouple is a device in a gas water heater that regulates the flow of gas by sensing the pilot light. If you don’t clean the thermocouple in a water heater, it will eventually prevent the water from heating up. Hence, hot water supply will cease.

how to clean the thermocouple in a water heater


Corrosion and buildup are some of the things that can affect a thermocouple. They can prevent power from reaching the pilot light, thus the water won’t heat up.

Though changing the thermocouple is not a difficult task nor is it costly. But before you conclude, first be sure it not merely dirty. If it is, a good clean up can get it back to working condition.

That is where we come in today. To tell you how to clean the thermocouple on a water heater.

It’s great you’re still with us! Now let’s get on to the process involved.



Steps to Clean the Thermocouple on your Water Heater

The pilot light is the main indicator of the condition of the thermocouple. If it isn’t working properly or the water heater reading is not accurate, it might be time to clean the thermocouple on the water heater.

The following are things you need to do to bring it back to top shape.

  1. Turn off the power. This is the first thing you must do; in the name of safety. You can get injured if you don’t do this, so, take precautions.


  1. Identify the thermocouple. The safety device is a thin metal tubing or a wire, if you will. It should be next to the pilot light tube. Depending on the type of water heater you have, you might need a wrench or screwdrivers to loosen the thermocouple for cleaning.

Emerson TC18 Universal Thermocouple, 18-inch

To get yours, click here





  1. Clean the corrosion or buildup. Use emery cloth, steel wool, or abrasive sponge to gently scrub off the buildup. Apply even pressure and be sure to scrub the threading of the screws that connect the thermocouple to the unit. Be careful about the type of cleaning product you use and ensure it is not flammable.


  1. Wipe with a lint-free cloth. After scrubbing, further clean the thermocouple of the water heater with a microfiber cloth to remove excess particles.


  1. Reattach the thermocouple. Once you’re sure the thermocouple is clean, fix it back to the unit.


  1. Turn on the water heater. Relight the pilot light too and wait to see if the water will heat up. If it does, congratulations! The cleaning solved the problem. However, if it doesn’t, then you might have to replace the thermocouple.



Replacing the Thermocouple

If you’re sure the thermocouple is bad, have hot water flowing in your home again by following these steps to replace it. You must turn off the power as described above.

  1. Detach the thermocouple from the whole. Use wrenches or screwdrivers (depending on which you need) to loosen the nuts and screws on both ends that connect the thermocouple to the water heater.


  1. Slide the thermocouple out of position. This will disconnect it on both ends.


  1. Use the old thermocouple to purchase a new one. If you will be buying a replacement thermocouple from the store, take the old one with you to ensure you get a match. If you’re going to buy one online such as this one, make sure you do a good comparison. Alternatively search with the brand name.


  1. Install the new thermocouple. If you purchased the right one, this should be an easy process. Slide the thermocouple into the metal bracket and tighten it in place. First, turn the nuts in place with your hands to avoid stripping them. Then tighten with light pressure using a wrench.


  1. Turn back on the water heater. If everything is done correctly, your water will heat up in a bit.




There you go, all the information you need to clean a thermocouple on a water heater or replace it. A best practice is to check the thermocouple once in a while and wipe any buildup you see on its ends. This will keep it working at its best and make it last longer. Thank you for your time.











Leave a Comment

Privacy Preference Center