How to Clean Thermocouple on Water Heater?

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Thermocouples can become rusty or dirty over time, which will cause the water heater to flutter the thermostat and not function properly. Although a thermocouple is made from a heat-resistant alloy, it still needs to be cleaned or replaced.

The good news is that you don’t have to replace it as long as its cracks are small and cleanable. This guide tells how to clean a stainless steel flange on a gas water heater for people who want to know how to clean a thermocouple on a water heater by themselves at home without hiring any professionals.

Things You May Need

In order to clean your thermocouple by yourself, you’re gonna need the following material by your side, so make sure to gather them up before you begin the process:

  • An adjustable wrench or end wrenches (any of the one)
  • A Screwdriver
  • A glue
  • Pliers (channel locks might also work well)
  • Corrosion remover

Detail Steps for Cleaning Thermocouple on a Water heater

Water Heater Thermocouple Cleaning

Step 1: Shut off Gas Supply

Before starting, make sure that the gas supply is shut off firstly. Use an adjustable wrench or open-end wrenches to turn the main gas supply line on a gas water heater off.

Step 2: Unscrew Thermocouple

After you have shut off the supply, remove the access panel and carefully disconnect all of the fittings for both the hot and cold water connections as well as the thermocouple. Take note that all of these should be glued or press fit so as not to leak any water from your system.

Step 3: Disconnect Fill Valve

Remove aerators from any faucets close to where your thermocouple is placed and then disconnect them if they’re threaded like most do. If they’re compression faucets (they usually twist and pull straight out), you’ll need to use slip-joint pliers or channel locks to remove them. Drain any water left in the lines by opening up all of your faucets and allowing the system to drain of its own accord.

Step 4: Loosen Thermocouple

You can now loosen or remove your old thermocouple from the gas water heater’s flange by turning it counterclockwise with adjustable pliers until it is free and clear of the mounting ferrule. Sometimes, a little wiggling and gentle pulling on the pliers is required for these types of fittings. Make sure that you also remove any corrosion that may be on the face of this fitting as well as around it before installing your new one in place.

Step 5: Clean Flange

Once everything has been disconnected and the old thermocouple has been removed, clean up the gas water heater’s flange with a wire brush to remove any corrosion, dirt or rust that may have formed on it. If your heater’s flange is stainless steel, you will need a stainless steel brush for best results.

Step 6: Install Thermocouple

After all of the rust and corrosion has been cleaned off of your water heater’s flange as well as around it, you can now install your new thermocouple in place by first inserting its threaded end into the fitting as far as it will go. You’ll also need to tighten down the compression ring on top of this fitting to secure it in place. Then, use an adjustable wrench or channel locks to tighten down the main fitting itself.

Step 7: Turn Gas Supply On

If everything has been done properly, it will be easy for you to turn your gas supply back on at this point. Afterward, all that’s left is to reattach all of your fittings that were removed in step two and then replace any access panels that may have come loose while working on your water heater system. Now, you can enjoy hot water once again!



As you can see from the above steps, installing a new thermocouple on your gas water heater is not as hard as one might think.

It merely entails following these steps in an orderly fashion and inspecting all of the connections to make sure that everything is clean, clear, and free of corrosion or rust before reassembling it all into place again. This way, your gas heating system will be good as new once more and ready to serve you for many years to come!

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