Thermopile Voltage Low: What it Means and What to Do?

If you have ever installed a water heater at home, then you must be familiar with Thermopile Voltage.

In this modern world where people have introduced numerous technologies, they have surely made our living standards easy, but what about those issues that come along with all this easiness?

In winter, the water heater is one of the biggest blessings, especially if you live in chilly areas, but the issue comes when your water heater suddenly stops working, and you are left with no clue.

Let’s discuss why your water heater’s pilot light suddenly stops blinking and keeps showing a red alert.

What is Thermopile?

Are you just done with the water heater installation, and you decided to check whether it is functioning properly or not, but you noticed the pilot light is off? This issue can occur due to some trouble during the installation method.

After resetting the light, if it again goes down, it clearly means that your water heater has a low thermopile voltage. Thermopile is the important part of a water heater that senses the heater’s temperature.

It combines different thermocouples, and the main task of the thermocouple is to keep the water heater temperature perfectly fine. If the thermocouple has low voltage, then your heater won’t be able to deliver warm water.

It is important to fix this low voltage issue if you want your heater functions appropriately.

What is Low Thermopile Voltage?

It is important to get the essential information regarding your newly installed heater so that you can resolve minor issues without calling anyone. Understanding this low voltage issue and how you can get out of it is also vital.

We all know that the pilot light plays a huge role in working the water heater. If it is on, it gives enough heat to the thermopile, but the water will no longer be warm once it is off.

A thermopile not only senses heat but also produces it. The heat is generated due to those thermocouples that it combines. If the gas water heater is installed in your home, then thermopile defines the failure of flame.

The flame is that light on the heater that dictates whether your heater is working fine or not. If it is light, it means that it is heating the thermopile, but as soon as it goes off, only a voltage drop is left, or it defines low voltage.

The thermopile will not be heated until you turn on the pilot light again. That’s why thermopile is the most important component in the water heater so ensure it is working fine.

How to Test a Thermopile?

You might be wondering about these scenarios depicting that our thermopile is at fault and needs to be recovered. We will do testing to examine, but how?

You do not need to be a professional for this process as by following a few steps, you will do this work in hardly 2 or 3 minutes. Have a look below.

1. Before moving towards the thermopile, you have first to set the multimeter. It is a tool that records the electrical values of your water heater. Ensure you have set the voltage to 1 or millivolts.
2. Once done, reach the gas control, from where you have to disconnect the wiring of the thermopile. Firstly, make it loose so that it can easily be detached. You can take any tool for this purpose, and it won’t require much time and effort.
3. Now you have to make a connection by attaching the black positive lead with the white one, and the red lead must be attached to the red wire of the thermopile.
4. Now set the pilot’s light. For this, you have to check the manufacturer’s instructions, so everything goes fine. The method to light the water heater’s pilot is different, so make sure you have gone through the manual instructions. Once it is light, the voltage will tend to enhance.
5. Keep pressing the knob of the thermostat until it goes to the maximum voltage. It will take some time, so be patient. You will also notice that as soon as the voltage increases, the reading on the multimeter will decrease.

Now how will you know that the thermopile is working healthily and is not at fault? If the reading it shows lies between 650 to 850, it means it is working fine.

However, if the readings go down to 400, it means a replacement is needed. Before changing the thermopile, ensure the manufacturers’ instructions because the ratings can be different for each water heater.

How to Replace a Thermopile?

Can you replace a thermopile at home without anyone’s need? Yes, you can do this work, but it requires your time, so if you have enough time, you can go ahead with this work to save some additional replacement costs.

Moreover, it also depends on your confidence whether you can jump into an electric work or not. A professional can complete this work in less than an hour, and he might perform it with perfection. The choice is yours.

In case you want to do it yourself, let’s have a look at some points that define how you can make this replacement.

1. Switch Off the Gas Supply

It is the most important step you must perform before doing any electrical work. Ensure the main gas supply is turned off to avoid any unpleasant accident.

Once it is off, pull out the cover so that you can clearly check all the components of the water heater. The water heater thermal switch must be off.

2. Detach the Wires

After turning off the gas supply, you must disconnect all the wires to begin working. This process is risky, so ensure you have followed all the safety precautions. One mistake can cause a big accident.

During this process, never twist tubes and wires. Various tools are available to disconnect the wires, so take the right tool that makes the work easy for you.

3. Uncover the Manifold Door

There is a manifold door inside the water heater that you have to uncover. Now remove the screws tightly holding this door. Later, you have to remove the burner assembly so that you can reach the thermopile.

There are too many wires and tubes inside the manifold door so ensure you are familiar with the order because once you are doing the replacement, it will be essential.

4. Remove Thermopile Wire

To remove the thermopile, you must disconnect its wires so that you can easily replace it. Before disconnecting the wire, you also have to get rid of the pilot assembly. The way you will remove all these things depends on the water heater you are using.

5. Get New Thermopile

Now you are all set to replace this component, get your hands on a new model. Before installing it, you have to untangle the thermopile wire first. Ensure you carefully fit the wire and thermopile into the manifold door.

6. Screw Pilot Assembly and Other Wires

As you have installed a new thermopile, so now set everything back in its right place. All the wires and tubes must be secured rightly in their order so that it doesn’t affect the functioning.

The pilot assembly must also be installed properly along with the manifold door.

7. Turn on the Gas

Once you have connected the manifold tube and the pilot tube, you can switch on the gas to test whether you have done everything correctly or not.

On pressing the knob, if you sense a gas smell, then it means there is something fishy, and you haven’t made the connection right. Correct it before proceeding with any other work.

8. Set the Temperature

If everything goes fine, you can set the temperature of the water as per the requirement by holding the knob. You are all done.

FAQs – Frequently Asked Questions

Thermopile replacement is simple if you follow the right steps. If you are still confused about the thermal switch water heater or do not know the difference between thermopile vs thermocouple, here we have made a list of some question answers that you might want to know.

What Causes Thermopile Low Voltage?

It normally occurs when your thermopile is at fault and it needs to be replaced. Moreover, it can also occur when the pilot light goes off due to windy temperatures. After turning it on, you can control the situation.

What Do You Do When Thermopile Voltage is Low?

You have to ensure whether it is due to a bad thermopile or the issue is due to any other reason. You can check the steps given in this guide above for testing.

How Do I Know if My Thermopile is Bad?

If the reading on the multimeter shows below 400, it means the fault is in the thermopile, and you have to replace it. However, if the reading lies between 650 to 850, your thermopile is healthy.

How Long Does a Thermopile Last?

If you are using it correctly and you also maintain it from time to time, it can even last for 7 decades. It entirely depends on your attention and care. It might cause little issues in between, but you will never need to replace it.

Final Thoughts

Is your thermopile voltage low, and now you are looking for ways to cover this situation? This detailed guide will surely help you to come out of this issue without anyone’s assistance and without spending an additional amount.

Thermopile can be at fault if you will not maintain them. However, it is important to check it with time so you will not have to buy a new model.

In this guide, we have depicted the right way to test your thermopile and how to replace it if needed. Also, if you do not know the water heater thermopile or what a bad thermocouple means, you will get full knowledge here.

Go through the entire article, and if you are still confused over anything, straightaway ask your queries. We will get back to you.