by Trevor Woods |
Last Updated: May 10, 2020 Nothing ruins a hot shower faster than a snuffed out water heater pilot light, Brrrr! Standing pilot water heaters need this flame to stay lit at all times in order to heat up your water.
When this flame goes up in smoke, the pilot light needs to be relit so that the burner can ignite and bring your water back up to temperature. The number one cause of a pesky pilot light burning out is due to a faulty
No need to call a plumber, we will show you how to easily relight you water heater and troubleshoot your water heater’s
How Do Thermocouples Work?
Before you relight the water heater pilot light, it’s helpful to understand the basic concept of thermocouples. A thermocouple is an electrical device that is comprised of two dissimilar electrical conductors forming an electrical junction.
The electrical conductors in thermocouples are two wires that are made from different metals that are joined at both ends inside the
Water heaters and other gas-fed heating applicants are equipped with a pilot flame for igniting the main gas burner as needed. When this flame goes out, there is a risk of unburned gas being released and this can result in an explosion. Thermocouples are used in these appliances for the prevention of such accidents. The
The tip of the
There are many different types of thermocouples and each has its own specific application. We will cover which style of thermocouples you are most likely to encounter.
Types Of Thermocouples
You might be wondering whether every water heater
Calibrations of different thermocouples have a varying environment and temperature range. And the diameter of the wire in the
Type K thermocouples are used for most general applications like in your home because they are low cost and have an average temperature range. Thermocouples with a wider temperature range are usually seen in industrial settings.
While selecting a
Replacement thermocouple for gas furnaces, boilers and water heaters.
How To Light A Water Heater Pilot
Word Of Caution
Lighting a pilot light, especially on a hot water tank can seem like an easy task. However, if done incorrectly, it can be quite dangerous. Always be careful when working with gas appliances.
A lot of modern appliances now operate via electronic ignition. However, standing pilot systems are still widely used, that’s why it’s important to learn the procedures for lighting a pilot light. The basic principles can be applied to water heaters, furnaces, boilers, gas fireplaces, pool heaters, and so much more!
Before proceeding, we feel it prudent to mention that while relighting a pilot, you need to pay utmost attention to your safety. In case the pilot fails to ignite, or you feel something is amiss, do not hesitate to call a professional. Gas appliances can be dangerous if not handled properly.
Before attempting to light a standing pilot, it is crucial that you read the instructions that are written on the side of the hot water tank or in the owner’s manual. Every system can have slight changes to the usual methods, and thus it is key that you follow the manufacturer’s guidelines to make sure that no accidents occur.
In case you are unable to see the combustion chamber while lighting the pilot, always use a flashlight instead of an open flame. There is no reason to take any chances.
Sealed Combustion
First, are instructions for modern water heaters with a sealed combustion chamber. With these models of hot water tanks, you will not have to access the burner assembly to ignite the pilot with matches or a long-reach lighter.
You will find everything needed for lighting the pilot right to the burner control module or gas valve. A looking glass is present in the access panel, which can be used to make sure that the pilot is indeed ignited.
1. Turn The Gas Valve To Pilot Position
The first step is to turn on the gas control knob to the PILOT position. This knob is found on the top of the gas valve.
2. Start The Flow Of Gas
You will then have to press and hold down the control knob to maintain gas flow.
3. Light The Pilot
You will find an electronic spark button mounted to the control module. This Piezo lighter will discharge an electrical spark every time it is depressed. You will hear an audible “click” when you are using the lighter.
While continuing to hold down the control knob use the Piezo lighter to ignite the gas. This may take multiple clicks if the pilot has been out for a while and the gas line is full of air.
You can look through the sight glass at the bottom of the combustion chamber to check to see if the pilot has been successfully lit.
4. Energize The Gas Valve
After you have confirmed that the pilot light is ignited visually, continue to hold the knob down for around 30 to 45 seconds. This will give the pilot adequate time to heat the thermocouple and confirm pilot light ignition to the gas valve. The pilot light will go out if the
Once you let go of the knob, ensure that the pilot remains lit. If the pilot light does fizzle out, start over and attempt to relight it again.
5. Turn The Burner On
With the standing pilot operating turn the gas control knob to the ON position. The burner should not take more than a few seconds to activate if the water temperature has cooled due to the pilot being out.
Depending on the size of your hot water tank your water should be back up to temperature in about 30 minutes. Done!
Open Combustion
Another system available on the market is an open combustion pilot system. In this case, the flame for lighting the pilot has to be provided by you. There is no electronic ignition involved.
1. Open The Combustion Chamber
The burner compartment panels have to be removed to open up the combustion chamber so you can light it. There is typically a metal cover panel that shields the gas lines and thermocouple and an inner door that can be removed or slid out of the way.
2. Turn The Gas Valve To Pilot Position
Next, make sure that the notch in the dial of the gas control knob is lined with the gas supply button. Turn the knob to PILOT position.
3. Start The Flow Of Gas
You will then have to press and hold down the control knob to maintain gas flow.
4. Light The Pilot
Now use a flame source like a lighter or long match and place it into the chamber so that the flame is directly beneath the orifice of the pilot supply line.
11" Long-reach wooden matches.
5. Energize The Gas Valve
Confirm that the pilot is lit visually. Continue holding the gas supply button for around 45 seconds to heat the
If the pilot light goes out after you release the pilot button try lighting the pilot again, making sure to keep the pilot button depressed long enough to thoroughly heat the thermocouple.
6. Turn The Burner On
With the standing pilot operating reinstall the hot water tank’s cover panels and turn the gas control knob to the ON position. The burner should not take more than a few seconds to activate if the water temperature has cooled due to the pilot being out.
Depending on the size of your hot water tank your water should be back up to temperature in about 30 minutes. Done!
Extend Your Reach
Use a long flexible
Rechargeable lighter that contains zero butane or liquid fuel. One change allows for up to 600 uses!
Safe and secure design that is windproof to guarantee your lighter works each time.
How To Test A Thermocouple
If your water heater pilot fails to stay lit, it’s time to test your gas system and see if something is worn out and needs to be replaced. Bad thermocouples are the number one reason why pilot lights fail to stay lit.
Testing Thermocouples Manually
To test for a faulty
Now release the button and check if the light is still there. If the light goes out or it has failed multiple lighting attempts it may have to be repaired or replaced.
Testing Thermocouples With A Voltmeter
A
Now turn on the multimeter by flipping on the power switch and adjust the settings dial to DC millivolts (mV). Connect the leads of the multimeter to the
Klein Tools Test and Measurement product line was exclusively designed from the ground up by electricians for electricians.
Years of field research, combined with extensive input from electricians across America, inspired the development of meters and electrical testers loaded with innovative, time-saving features.
You can now commence the test by starting the pilot light. Light the pilot as you normally would and continue to hold down the pilot button. Allow the
The thermocouple should reach about 25 millivolts with a range between 17 and 32 mV being acceptable. If the
How To Maintain A Thermocouple
Thermocouples are pretty low maintenance but sometimes they need to be cleaned to make sure they generate the millivolts needed to maintain the pilot light.
Whether you have a sealed or open combustion chamber you need to get access to the thermocouple underneath the water heater. Use steel wool or emery cloth to gently clean the tip of the
Steel wool super fine grade #0000 used in cleaning, polishing, buffing, and refinishing.
Keep It Consistent
If you have removed your
Keeping your thermocouple properly maintained and ensuring that your
How To Replace A Thermocouple
If your
1. Turn Off The Gas
The first thing that you need to do is turn OFF the shutoff valve on the gas line to your water heater. Turn the handle of the valve so that it is perpendicular to the pipe.
2. Remove The Burner Assembly
Next, unscrew the nuts at the control valve that secures the gas line, pilot tube, and
Handle With Care
Be careful not to kink or excessively bend the gas supply line or the pilot tubing. These are made of soft metals and can deform easily.
3. Remove The Thermocouple
Unscrew or pull out the old
When In Doubt
If you are unsure of the length of
Replacement thermocouple for gas furnaces, boilers and water heaters.
4. Install The New Thermocouple
Insert the replacement thermocouple in the holder that the old one was mounted in. Make sure the depth of the
5. Reinstall The Burner Assembly
Gently replace the burner assembly in the combustion chamber of your water heater. The burner assembly will typically have a bracket or mount that the assembly has to be placed on.
Brighten Up Your Workspace
Use a
6. Reconnect The Gas Valve
You will now have to reattach the gas line, pilot line, and thermocouple back into the gas valve. You can tighten the nuts with your fingers after threading them into place. They can be snugged up with the help of a small adjustable wrench. Make sure that you do not over-tighten them as these metals are soft.
7. Turn On The Gas
Once the burner assembly is reconnected, turn ON the gas valve that supplies your hot water tank.
8. Light The Pilot
Follow the pilot lighting instructions posted on the side of your water heater and visually confirm that the new
Turn the water heaters gas valve to the ON position to ignite the main burner.
Better Bubble leak locator is formulated to pinpoint the smallest leak quickly and easily.
Application and cleanup are safe and simple.
9. Test For Leaks
Once you are done, watch out for gas leaks. Use a leak detector solution or electronic sensor to make sure your connections are airtight. Tighten as needed. Your water heater should be back up to operating temperature within an hour. Done!
Conclusion
Knowing how to relight your water heater and replacing the thermocouple is a great way to keep your hot water tank running when you need it and you can save a ton of money if you fix it yourself. So put on your tool belt and start checking your water heater tank today, so you can enjoy an extra warm shower tomorrow.
Happy Plumbing!
Recommended Reading
How To Use A Water Hardness Test Kit At Home
Figuring out if you have hard water can be daunting. We will show you the best water hardness test kit you can buy and how to use it!
How To Unclog Your Bathtub Drain The Easy Way
Learn how to easily unclog your bathtub drain in 6 simple steps. Follow this guide and you'll be back to soaking in your tub in no time!
How To Repair A Garden Hose
Nothing ruins your outdoor fun faster than a leaking garden hose. Save money and your hose by fixing it yourself in five minutes flat!
How To Winterize Your Outdoor Faucets
Winterizing your outdoor faucets properly can be done quickly and save you from a frozen plumbing problems later on. We will show you how!
Plumber’s Grease: What Is It And How Do You Use It
You hear a squeak in the shower. DO NOT panic! It’s not a fuzzy pest. We will show you how to stop that squeak with plumber's grease!
How And When To Use An Internal Pipe Wrench
The internal pipe wrench shines in the world of rusty and broken plumbing. We will show you how to use this piece of plumbing ingenuity!