Top reasons why the water heater pilot light keeps going out

You’re looking forward to a warm shower on a chilly day but as you step into the shower, you’re greeted by icy cold water. And, this has been happening ever so often. Your water heater pilot light keeps going out. So, why does it happen? And, how do you get it repaired? 

We have all these answers and then some more. Fortunately or unfortunately, it’s not an uncommon problem if the pilot light keeps going out on the water heater. Many homeowners face it. The only solution is to find the source of the problem and tackle it at the earliest. Here, we will help you understand the reasons why the water heater pilot light won’t stay lit. And, give you easy fixes too. 

Find out your home's credit score

Check your home condition score to find out!

Check it out

What is a pilot light?

The pilot light ignites the burner and holds a continuously burning flame. Basically, it burns fuel or gas to produce heat. When your heating appliance is turned on, there is a gas release from the main burner. The pilot light ignites this gas to provide heat. The heat warms the main burner – heating the air or water inside your appliance which is then supplied to your home.  

Read more: Why is my electric heater not heating?

Now that you know what a pilot light is, your next question would be – why does my water heater pilot light keep going out? 

But before you go snooping around, do check if your water heater is still under warranty. In this case, you may be able to return it to the manufacturer or supplier for replacement or repair work.

If the warranty has expired, you will need to find out the plausible causes of the issue. The first step is to shut off the gas supply valve and wait a while for the heat to disperse. This will help prevent deadly leaks. Plus, it will make it safer for you to get to the root of the problem. 

Here are some of the likely culprits for this home maintenance problem. 

Dirty pilot tube

Dirt build-up over time is a common problem with most water heaters. If the pilot tube – that supplies gas to the pilot light for combustion purposes – is clogged with dirt or debris, the flame will go out.

How to solve the problem?

Detach the tube and carefully unclog it using a needle. This may take several minutes and attempts so you’ll need to be patient. Attach the tube back and light your water heater. A clear passage will make the flame blue and steady.

Obstructed thermocouple

The thermocouple is a safety device that opens or closes the gas valve when it senses that the pilot light is on or off so that there are no deadly gas leaks. It’s triggered by an electric current that’s produced by the pilot light. If your water heater pilot light keeps going out, a dirty thermocouple could be the reason. Grime may be hindering the electric current supply.

How to solve the thermocouple problem?

Turn off the main gas supply valve and wait for a few minutes for the thermocouple to cool. Now start scrubbing off all the dirt and grime using sandpaper.

Kinked or bent thermocouple

Keep in mind that the thermocouple should have a clear passage to the pilot light in order to open or close the gas valve upon receiving an electric current from the pilot light.

In the absence of a heat signal from the electric current, it will close the valve and cut off the gas supply.

How to solve the problem?

Make sure that the gas supply is off and the thermocouple is cool. Now, gently begin straightening or bending the thermocouple so that it’s close enough to the pilot light. It should slightly touch or wrap around the blue flame.

Broken thermocouple

If the thermocouple is in position and the pilot light still goes out, the device might be broken.

To find out if it is, you can do a diagnostic test with a multimeter. If your thermocouple is supplying a voltage that’s much less than 20MV, it’s indeed broken.

How to solve the problem?

You can consult an expert technician to find out if it needs repair or a complete replacement. 

Flex tube problems

The flex tube connects the gas controller to the burner. If there’s something wrong with the flex tube, there will be no gas supply to the burner for combustion. 

How to solve the problem?

Make sure the flex tube is not damaged or clogged. Such problems can cause gas leaks – reducing the amount of gas that reaches the burner. If you see any visible damage, may need to change the tube entirely. 

Problem with the electrical system

Poor wiring can be a problem if your electric water heater hasn’t been installed properly. That’s why it’s important to hire a licensed professional for your heater installation. If your water heater suddenly shuts down, your electrical system needs repair work.

How to solve the problem?

Switch off your water heater immediately and send for a technician. Do not attempt to fix the problem with the wiring system yourself.

Faulty main control valve

Although a main control valve issue is not so common, you cannot rule it out completely. If the pilot button doesn’t pop up after pressing it or if you’re getting hot water that’s hotter than the set temperature, the valve could be the problem. The valve regulates the gas water heater’s flow of gas and water pressure. If it’s faulty, it can unexpectedly close the gas valve – cutting off the gas supply completely or giving out a weak flickering flame.

How to solve the problem?

It can be fixed by a technician. However, you should think about replacing the faulty main control valve if you want your water heater to last. It will also prevent costly repairs in the future.

Last thoughts

A cold shower when you’re expecting a hot one can be frustrating. Additionally, all that cleaning, laundry, and hand washing in cold water can add to your inconvenience. 

If your water heater pilot light keeps turning off, it’s important to fix it at the earliest. The most common problems arise due to a thermocouple issue, a dirty pilot tube, or the main valve. Whatever the reason, once you understand what is causing the problem, you can do damage control as soon as possible. 

Read more: Water heater financing

Written by Ramona Sinha. February 8, 2023

Ramona is a content writer for Kukun. This experienced blogger uses simple and succinct words to decipher the complex phenomenon called life. An avid traveler, she’s a digital nomad at heart and an animal lover from the depths of her soul.