How To Replace Thermocouple On Water Heater

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Difference Between A Thermocouple And A Flame Sensor

Thermocouple Replacement on a Water Heater

As we mentioned above, your water heater may use a flame sensor instead of a thermocouple. Although, these terms may be used interchangeably, they are technically different.

A flame sensor is typically found on newer water heaters that use an electronic controller, where thermocouples are found on older heaters. While these differences are worth considering, they’re not ultimately all that impactful. Both thermocouples and flame sensors perform the same job, and in the end, that’s really all that matters.

Thermocouple For Water Heater Replacement

A thermocouple is a device utilized to monitor the liquid flow in water heaters. On older-model heaters with particular pilot lights, the instrument is normally introduced as the thermocouple, whereas on newer styles with an electronic system, the virtually same instrument is called a flame sensor. For our definition in this post, well introduce both instruments as the thermocouple for a water heater.

The thermocouple is an essential part of the pilot burner system and attaches to the control section on the other side of the water heater. It is a common instrument that modifies the heat from a burning flame form to the electrical output, permitting it to run like a switch to detect the flow from the gas source valve. In other words, when the thermocouple doesnt identify the flame, it avoids the gas source from sending gas to the section of burning. So, it is an important safety part of our water heater systems. Otherwise, an improper thermocouple for a water heater is the main reason why its pilot does not operate, or the burner does not run appropriately.

The kind of ignition style you have in your thermocouple for a water heater will specify how you fix it. With both a standing pilot or electronic type, the thermocouple is a part of the burner setup. However, with a standing style, there is only a pilot and thermocouple combined with the burner, while with an electronic model, there is both the thermocouple and pilot and the electronic igniter combined with them.

Furnace Pilot Light: Where It Is And What Does It Do

Old furnaces rely heavily on the pilot light to generate heat, which is why it is so crucial to keep the pilot light on. When the gas valve is opened, the flame will continue to burn constantly, igniting the gas. The heat generated by this process then heats the air that is drawn into your furnace, which is then dispersed throughout your house. If your furnaces pilot light is out, you may notice that it is spewing chilly air into the house. The failure of the pilot light is one of several probable causes of your furnaces inability to switch on.

You may find the pilot light by following the gas line into your furnace and looking for it there.

From there, you should be able to see a short tube that runs from the gas valve to the burner itself.

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Pilot/electrode Assembly Inspection Cleaning And Replacement

Step 1. Turn off the gas provide to the water heater. Rotate knob of gas management/gas valve to OFF place.

Step 2. Remove outer jacket door.

Step 3. Remove the correct side of the internal door per SERVICE PROCEDURE RG-I, steps 3a via 3c.

Step 4. Disconnect thermocouple/thermopile, pilot tube, and feedline from gas management/gas valve.

NOTE: Feedline nut for pure gasoline management makes use of right-hand threads, LP management makes use of left-hand thread.

Step 5. Disconnect piezo ignition wire from the piezo igniter.

Step 6. Remove burner meeting from the combustion chamber.

Step 7. Remove pilot/electrode assembly from the feedline

Step 8. Inspect pilot for the next:

1) Primary air openings for blockage. Must be free from any particles .

2) Kinks or cracks within the pilot tube. If discovered, the pilot should be changed.

Step 9. Inspect pilot orifice:

1) Remove ½ nut from the underside of the pilot assembly.

2) Remove the pilot tube and pilot orifice.

3) Inspect the pilot orifice for blockage, should be cleaned or changed.

Step 10. Install pilot/electrode assembly to feedline, safe with the screw from step 7.

Step 11. Re-Install burner assembly into the combustion chamber, join feedline, pilot tube, and thermocouple/thermopile to gas management/gas valve.

Step 12. Install internal door per SERVICE PROCEDURE RG-I, steps Four via 13.


  • For Honeywell Control, rotate the knob counter-clockwise to the OFF place.

What Happens When A Thermocouple Malfunctions

How to Replace a Water Heater Thermocouple
  • To your pilot light, a thermocouple serves as a type of co-pilot, allowing the gas burners on your water heater to be ignited.
  • Heating repair services in Raleigh, North Carolina, are frequently called upon to deal with thermocouple failures, in part because the device is so critical to the effective operation of your heating system.
  • What happens when a thermocouple stops working properly?
    • In a nutshell, the heater need assistance.
    • The thermocouple is responsible for controlling the flow of gas into the furnace.
    • It detects when the pilot light is turned on and permits gas to be released into the burners, so initiating the heating process of the water.
    • The thermocouple is normally located fairly close to the pilot light, and depending on the nature of your water heater, they may even be a part of the same component.
    • Normal operation of the thermocouple is to simply shut off the gas supply to your heater when it malfunctions or isnt operating.

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    Why Boiler Pilot Light Goes Out

    A malfunctioning, misaligned, filthy, or damaged thermocouple is frequently the source of your pilot lights failure to illuminate properly. It is the thermocouple that keeps the gas valve from opening if the pilot light is not lit. Your pilot light may not function properly if there is an issue with your thermocouple, or if it is just coated with dirt and debris.

    Lack Of Combustible Air

  • The lack of sufficient combustible air in your gas water heater might also be a contributing factor to its inability to maintain a steady flame.
  • To keep the pilot light on in your water heater, youll need to blow air into it.
  • Otherwise, the flame will be extinguished.
    • Take precautionary measures to ensure that the water heater is not surrounded by material, such as litter or lint, which might increase the quantity of combustible air present.
    • Maintain as much cleanliness as possible in the surrounding region.

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    Shivratri 2022 Date California

    Mr. Heater Tank Top Thermocouple Assembly replacement for the MH15T, MH15C, MH30T, and MH45T model series without tip over connection. $8.40 Availability: In stock Add to Cart Enerco California Prop 65 Statement Description Reviews. #1 Commercial Patio Heaters – ideal for Restaurants, Hotels, Resorts, Country Clubs, Night Cubs & Bars, Homes. … Replacement Parts in Stock. Details on Quality. … so feel free to contact us regarding your patio heaters, outdoor heater, outdoor propaneheater needs. Legacy Heaters. 3471 Federal Highway, Fort Lauderdale, Florida 33306, United. Heater Tank Top Thermocouple Assembly replacement for the MH15T, MH30T, and MH45T model series without tip over connection. … Replacement for Mr. Heater models: MH15C, MH15CS, MH15T, MH15TS, MH30T, MH30TS, MH45T without tip over connection Prevents unburned propane release Replaces part 17425 Write Your Own Review. Only registered users.

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    Mr. Heater Big Buddy Pilot Assembly- Thermocouple 78422. SKU: MH-78422. Replacement pilot assembly and thermocouple for Mr. Heater Big Buddy MH18 series heaters. $24.95. Solution: When an older patio heater will not stay lit, it often times means the thermocouple has failed. Replacementthermocouples are available for purchase for most units. Problem: Propane tank is freezing. Solution: There is a leak at the propane tank/regulator connection. Make sure the regulator is attached securely to the propane tank.

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    How Do You Know If Your Water Heater Thermocouple Is Bad

    How To Install / Replace a Thermocouple in a Hot Water Heater

    A bad thermocouple is the most common reason for a water heater pilot light that wont stay lit. And its not unusual for it to wear out.

    Ironically, this happens sometimes due to the very nature of the device: the constant change in temperature results in a worn-out or stressed thermocouple. It can also malfunction when residue or soot buildup causes the flame to be blocked.

    A bad thermocouple can result from the following:

    • A bent thermocouple: If the flame isnt slightly touching the thermocouple, it could be bent or misaligned. Simply bend it toward the pilot.
    • A dirty thermocouple: As noted above, soot or other residue can prevent it from working. To solve this problem, remove the thermocouple and clean it off. Caution: Always turn off the gas valve before you remove a thermocouple.
    • A broken thermocouple: This can result from wearing out. If electricity does not run through the thermocouple, its broken. To test this, use a multimeter. If the voltage is less than 20MV, it is damaged and needs to be replaced. Read below for instructions on how to do that.

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    How To Replace A Thermocouple On Your Water Heater

    There can be many causes when you have hot water heater problems, and one of those is the pilot light for your gas water heater. If your water heater pilot will not remain lit, then the thermocouple is probably at fault and its time to get a thermocouple replacement , as there is no fixing a broken thermocouple it has to be replaced. Fortunately, the new part should only cost you five or ten bucks, and as a home improvement project there are only six simple steps on how to install it yourself, if you know your way around the water heater.

    What is the thermocouple exactly? This little thermoelectric device is there to turn off the gas when the pilot flame turns off. The thermocouple tip is a stub of thermocouple tube that goes from the pilot to the gas controller, and at the pilot end, both the pilot and thermocouple are attached to a bracket that fastens to the burner assembly. It controls the gas flow to the igniter by ensuring there is heat present from the standing pilot light. If there is a blockage somewhere in the chamber, then therell be no gas flow in the copper tube, preventing fire in the combustion chamber, and should be part of your troubleshooting when looking at what is going on.

    One quick note before you go out and buy a thermocouple: first, see if the tube that feeds gas to the pilot light is clogged up or not. If the tube has an obstruction, then you might be able to simply blow it out or to use some thin wire to get it out of the way.

    Wait 5 Minutes Then Turn Gas To Pilot

    Immediately after waiting 5 minutes, switch the gas valve to the PILOT position.

    It is vital that all of the gas has dissipated before switching the gas position to the pilot position. A few of minutes might be the difference between a peaceful society and a disasterous one. Keep in mind that gas is quite explosive!

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    Causes Of Thermocouple Failure Part 1

    It is possible that a failing thermocouple will result in inaccurate readings and cause significant difficulties. However, there are a few circumstances that might cause thermocouples to fail, despite the fact that they are designed to be durable. It will be discussed this week how metal fatigue and oxidation are both possible hazards to the thermocouples in your system.

    No Hot Water Restore It Yourself

    White Rodgers 24 in. Universal Replacement Thermocouple

    Your gas water heaters burner chamber has whats known as a thermocouple, which is a little metal cylinder that sits directly in front of the pilot light. The thermocouple is a safety device that detects when the pilot light is on and has to be replaced. If the pilot light goes out, the thermocouple sends a signal to the gas valve, which keeps the valve closed until the pilot light returns.

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    How To Disable Thermocouples

    If your gas-fired equipment requires heat, a thermocouple will alert you when it is necessary to turn on the burners.They may be used with any device that has a standing pilot light, such as water heaters and furnaces, according to the manufacturer.Typically, one end of the thermocouple is linked to the main gas control valve of the appliance, while the other end of the thermocouple protrudes straight into the pilot light.It is necessary to disconnect thermocouples from their source by removing either one of their ends from it.

    How To Reconnect The Gas Control Valve

    When the new thermocouple is set up for both electronic model and standing pilot styles of water heaters, the burner, pilot, and thermocouple should be reconnected to the gas control valve.

    Reattach the Gas Tubes

    The pilot source tube, burner tube, and thermocouple must be reconnected properly to the gas control section.

    Turn on the Gas

    The shutoff valve part on the gas source piping should be opened and switched to the ON state. Now, you can set the systems thermostat to a suitable temperature.

    Test the Water Heater

    You can check the function of the supply tube and pilot source at the control section for gas leakages by employing a soap-and-water method. In this way, you should cover the gaps with the soapy liquid and look for new bubbles that determine a leakage. If leakage is seen, you must seal all connections and recheck them by the same method.

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    Faulty Thermocouple Triggers Pilot Light To Go Out

    It is meant to shut off the gas valve if the pilot light goes out, and it is used in conjunction with a thermocouple. Thermocouples can be damaged or worn out over time. If the thermocouple is incorrectly positioned or malfunctioning, the gas valve may be incorrectly shut off, as well as preventing the pilot light from keeping lit.

    Installing The New Thermocouple

    How To Replace A Water Heater Thermocouple
  • Uncoil the new thermocouple and install the thermocouple end in the pilot assembly.
  • Reinstall the pilot assembly in the main burner assembly. Make sure the pilot assembly is pointing properly at the main burner and that the thermocouple length is adjusted so that the thermocouple tip is immersed in the full pilot flame.
  • Reinstall the main burner assembly in the burner compartment. Verify that the tip of the main burner assembly engages the burner support tab inside the burner compartment.
  • Gently reinstall the main burner tube in its port in the main gas valve and start the nut.
  • Reinstall the pilot burner tube in its port.
  • Route the thermocouple tube so it is not kinked or twisted and insert the end into the main gas valve thermocouple port. Start the thermocouple nut.
  • Tighten all three nuts firmly but gently. It is easy to strip out the threads in the aluminum main gas valve while trying to start the brass nuts.
  • Make sure that all three lines are firmly attached to the gas valve.
  • Turn on the appliance gas shut off valve.
  • Follow the manufacturers instructions to light the pilot.
  • Replace the interior sliding burner compartment door.
  • Replace the exterior burner compartment door.
  • After verifying that the pilot is burning properly, turn the water heater thermostat to the desired temperature. The main burner should ignite and burn properly.
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    Water Heater Thermocouple Thermocouple Replacement Guide

    A buyers guide to water heater thermocouples, as well as troubleshooting, repair, and a step-by-step replacement guide The replacement of a thermocouple is a straightforward procedure. As long as you are handy with tools, you should have no trouble. To learn more about thermocouple components, visit this page.

    A Worn Out Thermocouple Is One Of The Most Common Gas Water Heater Problems

    Thermalcouples wear down over time, causing the pilot light to go out, the burner to not fire, and the lack of hot water to result.First, try re-igniting the pilot by following the instructions on the tanks side panel.It is possible that the thermocouple is defective if the pilot ignites but the flame goes out as soon as you release the button after holding it for 60 seconds.It is feasible to change the thermocouple without having to disassemble the burner assembly, and many repair technicians do so.In this case, removing the burner assembly as we have done simplifies the task of replacing the thermocouple and provides an opportunity to vacuum out the burner compartment while youre at it, as well as clean the burner.Even though this work is straightforward, you should not do it unless you are familiar with how to turn off the gas to the water heater and are confident in your ability to relight the pilot.

    If you want to remove the burner, youll also need a screwdriver to remove the access cover, as well as a tiny brush and dishwashing detergent to check for leaks.A wide variety of thermocouples for water heaters may be found at most hardware stores and home improvement centers.Remove the old thermocouple and take its temperature reading.Then purchase a replacement in the same size.

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    Remove The Old Water Heater Thermocouple

    Apply firm pressure when twisting and pulling the thermocouple from its mount. It would be best to do this slowly to avoid deforming, bending, or damaging the thermocouple-pilot tube connection.

    Pull the old water heater thermocouple through the manifold cover opening or a rubber grommet. You can also cut the thermocouple if you find it challenging to pass the thermocouple through the grommet or manifold cover opening.

    Pro Tip: I advise you to bring the old water heater thermocouple to the store to buy the correct water heater thermocouple replacement. It will also be an excellent idea to consider buying a new manifold cover gasket if you intend to change the old one.

    How To Diagnose And Fix The Water Heater Thermocouple

    No Hot Water? Restore It Yourself with this Easy Fix

    Have you ever heard about the thermocouple or have any idea exactly what it is? Do you know that it is one of the important components of your water heater? Sometimes when the thermocouple breaks down you may think that the water heater needs replacement. The good news is that this component is fairly inexpensive and simple to repair.

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