Thermopile Voltage Low? Read this

By SmartHomeBit Staff •  Updated: 06/13/23 •  11 min read

The thermopile is a crucial component of water heaters, responsible for generating the voltage required to ignite the gas. A thermopile is a device comprising several thermocouples connected in series or parallel. When exposed to heat, each thermocouple produces a voltage, which is added to the total voltage produced by the thermopile. In water heaters, the pilot flame heats the thermopile, producing a voltage that opens the gas valve and allows the burner to ignite. The functionality of a water heater depends on the proper functioning of the thermopile. Low voltage readings can result in the malfunctioning of the heater. In this section, we will explore the definition and function of the thermopile, emphasizing its significance in the operation of water heaters. Join us as we uncover the critical role of the thermopile in ensuring reliable and efficient water heating.

Definition and Function of Thermopile

Thermopile is a device with many thermocouples joined together. Its purpose? To change thermal energy into electrical energy. This powers up parts of the water heater. It can detect temperature changes caused by the pilot flame. This then generates electricity to turn the gas valve and control the flow of gas. This heats up the water in the tank. Without a working thermopile, the water heater cannot do its job. So it’s important to clean or replace it when needed. This will make the water heater last longer.

Importance of Thermopile in Water Heaters

Thermopile is a must-have for gas-powered water heaters. It creates electrical current which powers the gas valve, letting hot water flow easily. Without a working thermopile, the water heater will not work.

To avoid problems with the thermopile, regular maintenance of the water heater is key. Issues like a pilot light that won’t stay on or inconsistent hot water temperature could mean there’s a problem with the thermopile. Low voltage readings are risky and can lead to significant water heater issues.

To fix low voltage readings, try cleaning the thermopile lead connections and tips or adjusting the pilot flame. Replacing the thermopile may be necessary in extreme cases.

It’s essential to understand that a functioning thermopile is necessary for reliable performance and efficiency of gas-powered water heaters. Regular maintenance can identify inadequate voltage inputs before they become serious problems.

In summary, the thermopile is very important for water heaters. Regular maintenance should be a top priority to make sure your gas-powered water heater works well and efficiently.

Low Thermopile Voltage: Causes and Symptoms

If your water heater is not producing enough hot water, you may be experiencing low thermopile voltage. In this section, we will take a closer look at the causes of this issue and the symptoms that can arise. Low thermopile voltage can affect water heaters by preventing them from producing enough hot water. Some common causes of this issue include a faulty thermopile or a clogged air vent. By understanding these factors, you can take proactive steps to address this issue and ensure that your water heater operates at peak performance.

How Low Thermopile Voltage Affects Water Heaters

Low thermopile voltage in water heaters can be a problem. It affects the efficiency and performance of the machine. The voltage is proportional to the temperature difference between its two sides.

If left unattended, there can be issues like the pilot light not staying lit. This means users may experience cold water instead of hot water. Unexpected shutdowns may also occur.

Neglecting the voltage can reduce the machine’s efficiency and lifespan. Sounds from the machine or no hot water may be noticed.

Regular cleaning and adjustment, along with replacing faulty components, can prevent such problems. A licensed professional can check the machine and make any adjustments. Quick action is needed to avoid replacing the entire equipment.

It’s important to note that the pilot light may be the source of the issue. The whole system should be evaluated to determine the cause of low thermopile voltage.

Common Causes of Low Thermopile Voltage

Low thermopile voltage is a major issue when it comes to water heaters. Dirty or clogged pilot assemblies, faulty wiring, damaged gas valves and weak flames are common causes. These can interrupt the power supply and reduce electricity output.

To prevent repairs, maintain your water heater regularly. This can detect issues related to low thermopile voltage before they become bigger. Take proactive measures to ensure it’s working properly and avoid malfunctions and breakdowns.

Don’t wait until your water heater breaks down. Include maintenance routines in your schedule and fix underlying problems quickly. With the right care, your water heater can work efficiently for years.

Symptoms of Low Thermopile Voltage in Water Heaters

Low thermopile voltage in a water heater can cause issues with its function. The thermopile is vital for generating electricity for the gas valve and pilot light. Low voltage tells us that electricity is not being generated enough to power the heater.

Problems such as no hot water, inconsistent hot water, inconsistent pilot light flame, and difficulty with starting could all be symptoms of low thermopile voltage. However, these could mean other problems, so it’s best to call a technician for proper diagnosis and repair.

Keeping the water heater up to date with regular maintenance prevents such issues. Cleaning the thermopile and adjusting the pilot light flame usually fixes it. In more serious cases, replacing the thermopile is necessary.

If you know the symptoms of low thermopile voltage, spotting the problem is easy. So, if your water heater is giving you any of the above signs, get it checked and repaired by a professional.

How to Fix Low Thermopile Voltage

If you’ve noticed that your furnace or gas log fireplace isn’t producing enough heat, it could be due to low thermopile voltage. The thermopile is a device that converts heat into electrical energy, which is then used to power the heating appliance. To fix the issue, you can follow these simple steps:

1. Clean the thermopile: Over time, the thermopile can become dirty or corroded, which can cause it to produce less voltage. To clean the thermopile, turn off the gas supply and wait for the appliance to cool down. Then, use a soft brush or cloth to gently remove any dirt or debris from the thermopile.

2. Adjust the pilot light flame: If the pilot light flame is too low, it can also cause low thermopile voltage. To adjust the flame, locate the pilot light adjustment screw on the appliance and turn it clockwise to increase the flame size.

3. Replace the thermopile: If cleaning and adjusting the pilot light flame do not fix the issue, you may need to replace the thermopile. This is a more advanced repair that should be performed by a professional.

By following these steps, you can restore your heating appliances to their former glory and ensure that your home stays warm and cozy during the colder months.

Cleaning the Thermopile

The thermopile is crucial for converting heat energy into electrical energy in water heaters. If it’s dirty or covered in soot, it can block its ability to generate enough voltage. This causes low voltage readings, which affects performance.

To keep your water heater in top condition, you must clean the thermopile regularly. Here’s how:

  1. Turn off the water heater and let it cool.
  2. Remove the access panel on the front of the tank.
  3. Spot the thermopile and use a soft cloth or brush to clean it. Don’t bend or break the wires.
  4. Put back the access panel and switch on the gas valve.
  5. Relight the pilot and check the voltage of the thermopile.

Cleaning won’t always fix low voltage readings. Faulty wiring, broken parts, bad installation checks, or other issues could be causing it. In that case, get professional help.

When the thermopile is neglected or broken for a long time, it may need replacing. Scheduled maintenance is the best way to avoid costs and keep performance steady.

So, to ensure hot showers, keep the thermopile clean and functioning. If neglected, it can reduce voltage and prevent hot water. Clean it regularly and call for help when you need it.

Adjusting the Pilot Light Flame

For optimal thermopile voltage, and to get a constant supply of hot water, it is crucial to adjust the pilot light flame! Here’s how:

  1. Shut off the gas supply valve and wait 5-10 minutes for any left-over gas to dissipate.
  2. Find the pilot light assembly at the bottom of the water heater.
  3. Remove any panels that may be covering the assembly.
  4. Use a flathead screwdriver to change the flame size, by adjusting the screw on top of the pilot light tube.
  5. Turn on the gas supply valve and relight the pilot light, following the manufacturer’s instructions.
  6. Verify that the flame is stable and blue, with a small yellow tip. It should not flicker, or be too low or too high.

If, after adjusting the pilot light flame, your thermopile voltage is still low, consider cleaning or replacing it. Remember to turn off all power sources, and to take safety precautions, when changing any part of your water heater. Replace your outdated thermopile and say goodbye to low thermopile voltage!

Replacing the Thermopile

When a low thermopile voltage is detected in water heaters, replacing the unit may be necessary. It generates electrical current for the heating process.

To replace it, three steps must be taken:

  1. First, shut off the gas supply valve.
  2. Next, remove the old thermopile.
  3. Lastly, insert and secure a new one into its spot.

Before replacing, eliminate other potential causes. Clean the pilot light and adjust its flame if it’s not strong enough.

Homeowners should schedule check-ups with certified professionals to inspect and repair the water heaters. They’ll check gas pressures, ventilation, flue drafting, burners, heat exchangers, and line pressures.

Importance of Regular Maintenance for Water Heaters

The importance of maintaining your water heater is huge! Keeping it in top condition helps to ensure optimal performance and long life. Neglecting maintenance can lead to low thermopile voltage and no hot water.

To avoid these issues, it’s key to check and clean the components regularly. This includes inspecting the thermopile, gas burner assembly and pilot light.

Besides cleaning and inspecting, there are other maintenance tasks that mustn’t be forgotten. Draining the tank and replacing the anode rod are both essential. If not done, sediment will build up and reduce efficiency, shortening the heater’s life.


Lastly, low thermopile voltage is a typical problem with gas fireplaces and stoves. To fix it, it’s important to take a step-by-step approach and look at the possible causes, such as a dirty or broken thermopile, weak pilot flame, faulty gas valve, and electrical issues. Safety must be kept in mind when doing repairs. Seeking expert help may be the best option. Knowing how to diagnose and repair the problems efficiently can save time and money.

FAQs about Thermopile Voltage Low

What is “water heaters thermopile voltage low” error message?

“Water heaters thermopile voltage low” is an error message indicating that the thermopile in a water heater is not functioning properly and needs to be replaced.

What is a thermopile in a water heater system?

A thermopile in a water heater system is a device made up of thermocouples that detect temperature without contact and convert thermal power into electrical power. It generates heat using its arrangement of thermocouples and provides the necessary current for the electronic system controlling the temperature of the outgoing water.

What are some causes of low thermopile voltage in a water heater?

Causes of low thermopile voltage in a water heater can include cold junction errors, loose wires, faulty internal units, and location in a windy area. It is important to understand these causes before attempting to fix the problem.

How can I fix low thermopile voltage in my water heater?

Three ways to fix low thermopile voltage in a water heater are cleaning the thermopile, adjusting the pilot light flame, and replacing the thermopile. It is recommended to have relevant experience before attempting to fix it.

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Does the website offering free estimates for hiring local home service professionals include plumbers?

Yes, the website offering free estimates for hiring local home service professionals includes plumbers and is a useful tool for anyone experiencing issues with their water heater or other home appliances.

SmartHomeBit Staff