How to Replace Thermocouple On Water Heater

To guarantee the optimal functioning of your water heater, it’s essential to be familiar with its key components and their maintenance. A critical component is the thermocouple, which, along with the pilot assembly, plays a pivotal role in the heater’s operation.

Over time, the thermocouple can wear out or get damaged, causing your water heater to malfunction.

Common signs of a faulty thermocouple include the pilot light going out frequently, the water not heating up as expected, or a gas smell near the water heater. Replacing the thermocouple is necessary to ensure your water heater’s safe and efficient operation.

How to Replace Thermocouple On Water Heater

You can perform a simple hot water heater thermocouple test to know when to replace this component. Start by turning the gas control knob to the “pilot” position and holding it down. While holding down the knob, light the pilot light. Once the pilot light is lit, hold the knob for about 60 seconds.

If the thermocouple works correctly, it will generate enough voltage to keep the gas valve open. However, if the thermocouple is faulty, the gas valve will close, and the pilot light will go out shortly after releasing the knob. If that is the case, you should replace this component by following this guide:

how to replace thermocouple on water heater

Read also: Pilot Light Keeps Going Out on Water Heater

● Turn Off the Gas Supply

Before starting, ensure the gas supply is turned off. Locate the gas control valve and turn it to the “off” position. If you need help with the location or how to turn off the gas supply, consult the manufacturer’s instructions or consider contacting a professional.

● Prepare the Tools and Materials

For the next step, gather the necessary tools and materials. You will need an adjustable wrench, a wrench set (if required for your specific water heater model), and a replacement thermocouple.

Read also: Gas Hot Water Heater Venting Requirements

A universal thermocouple for water heater is often recommended when replacing a thermocouple. This type is compatible with most water heaters, making it a convenient and widely available option. 

● Access the Thermocouple

Firstly, remove the access panel or cover on your water heater to reveal the internal components, including the thermocouple and pilot assembly. This panel is typically situated near the water heater’s base. Use a screwdriver to unscrew and remove the panel.

● Disconnect the Old Thermocouple

Locate the thermocouple assembly. It is connected to the gas control valve and the pilot light assembly. Carefully detach the thermocouple from both ends, using an adjustable wrench to loosen the fittings.

● Install the Replacement Thermocouple

Now, install the new thermocouple. Carefully connect it to the gas control valve and securely attach it to the pilot assembly. Tighten all fittings with an adjustable wrench. Ensuring that the thermocouple is correctly aligned and positioned close to the pilot light is crucial for optimal performance is crucial.

● Reassemble and Test

Once the new thermocouple is installed, reattach the access panel or cover, securing it with screws. Turn on the gas supply, and follow the manufacturer’s instructions to relight the pilot light.

After relighting the pilot, hold down the gas control knob for approximately 60 seconds to allow the thermocouple to heat up and generate voltage. If the pilot light remains lit after releasing the knob, you have successfully replaced the thermocouple.

Cost to Replace Thermocouple On Water Heater

The cost to replace a thermocouple on a water heater can vary depending on several factors, including the type of water heater, the brand, and the region. On average, a thermocouple costs range from $20 to $150.

If you hire a professional plumber to replace the thermocouple, the cost typically averages around $150. This cost covers not only the replacement of the thermocouple but also the expertise and labor involved in ensuring a proper installation.

On the other hand, if you opt for a do-it-yourself (DIY) approach, the cost will be limited to the price of the thermocouple, which averages around $20.

Can I Replace Water Heater Thermocouple Myself?

Yes, you can replace this component yourself by knowing how to replace thermocouple on water heater according to the guidelines above.

However, it’s important to remember that working with gas appliances carries inherent risks, and if you feel unsure or uncomfortable with the task, it’s advisable to seek professional assistance.

It’s important to perform a safety check. Ensure that there are no gas leaks around the connections. You can do this by applying a soapy water solution to the connections and watching for bubbles indicating a leak.

If you detect a leak, immediately turn off the gas and tighten the connections before retesting. Regular maintenance of the thermocouple and pilot assembly can significantly extend the life of your water heater and improve its efficiency.

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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.