7 Reasons Why Water Heater Pilot Light Won’t Stay Lit

Water heaters are one of the most imperative home appliances. But, it is frustrating when the water heater pilot light won’t stay lit. 

If you are not a plumber or technician, then we can envision that right now, nothing is more irritating than dealing with a water heater pilot light keeps going out not thermocouple. 

Aside from inhibiting the furnace from working appropriately, it can also refuse to provide you with steamy hot water for a morning shower. 

There are several reasons why the pilot light goes out repeatedly. We will try to tell you about all the potential reasons your unit is in such as condition, along with easy solutions you may be able to take care of yourself. 

We always recommend hiring professional service for intricate or hazardous repairs- either a plumber or gas company. We will let you know which problems should be resolved by experts only.

7 Reasons Why Water Heater Pilot Light Won’t Stay Lit


Water Heater Pilot Light Won't Stay Lit

If your natural gas water heating device trips off, again and again, you may have a faulty thermocouple. 

Most gas-powered models utilize a standing pilot to ignite the burner. Main gas valve supplies and the thermocouple monitor the gas for pilot assembly. 

The thermocouple is a heat-detecting probe. It is a significant part of the pilot assembly and assembles just above the pilot flame. 

When the pilot light is working correctly, the thermocouple will create a trivial current that is given back to the gas valve to keep the gas moving to the pilot light.

Nevertheless, if the thermocouple is damaged, it will not identify the flame, and the gas valve will not acquire the required power signal to keep the gas streaming to the pilot assembly. 

It sits in the pilot flame constantly and will ultimately trip off. To test the thermocouple, you will need special test tools. 

Replacing it is the most effective way of troubleshooting. Check that the pilot flame is clean and fully links with the probe’s end before censuring the thermocouple. 

While replacing it, you won’t have to deal with any gas fittings. However, local protocols may require that a specialized plumber fix the issue.  


Burner is another important reason why a water heater pilot light keeps going out. It burns the incoming gas to produce steamy warm water. 

If it is defective, the pilot light won’t function properly. We would not recommend you to fix or change the burner yourself, but you can test it to see if this is a possible issue. 

Activate the warm water fixture and allow it to run for a few minutes. Go to the unit and listen carefully for the burner’s sound kicking on. It usually produces a whump or whoosh sound. 

If you don’t hear any sound, it is a clear sign that your burner is defective. Call an expert to have them completely inspect it and change any malfunctioned components.

Dirty Pilot Tube

dirty pilot tube

If your water heater pilot will not light, then the dirty pilot tube can also be blamed. 

If you are speculating how it can hinder your device from operating, your pilot tube may be obstructed or wholly blocked by dirt, and the gas will not travel as it should. 

In such a situation, it requires complete cleaning to work correctly. Take the necessary safety precautions and then clean the tube with a small needle. 

Look out for large substances as they might be the biggest cause of a water heater not staying lit. 

When you are done, check the tankless water heater and see if the pilot light stays lit. If the water heater pilot goes out, remove the tube and clean it again.

Flex Tube Problems

kinked flex tube

A flex tube is another likely reason a water heater pilot keeps going out. This tube links directly to the gas controller and guarantees a stable flow of gas. 

Nonetheless, sometimes, the pipe rotates around and inhibits the appropriate system function. In such a scenario, untwine the tube to get rid of the issue. 

If it does not fix the problem, replace the tube. Flex tubing issues are rare compared to thermocouple problems.

Main Thermostatic Control Or Gas Valve


The thermostatic control or gas valve can also be the possible reason for the pilot light tripping off repeatedly. It is also called the main control valve. 

This problem occurs occasionally, but it is a potential cause of a water heater pilot light won’t stay lit. This problem also needs a professional’s knowledge and expertise. 

They will thoroughly inspect the part with a multimeter to find out if it is faulty. If yes, they will either repair or replace the part.

Lack Of Combustible Air

Lack Of Combustible Air

Lack of combustible air is another cause of pilot light won’t stay lit on water heater. Your appliance needs air to keep the pilot light igniting; otherwise, it trips off. 

Make sure your device is not surrounded by dirt, debris, and other impurities to enhance the amount of combustible air. The neighboring area of your heater should be clean.

Electrical System Defect

Indecorous wiring can also prevent the pilot light from staying lit. This problem commonly occurs in electric water heaters compared to gas heaters. 

If your machine has wrong wiring, it can experience numerous electrical issues. In such situations, you won’t be able to get hot water. 

If your appliance has an electrical flaw, the breaker shutdown will automatically turn off the main breaker. So, talk to a technician or plumber to check the electric wiring.

What Should You Do If The Hot Water Heater Pilot Light Keeps Going Out?

DIY Method

All water heaters arrive with some guidelines. Before you try to fix your device, make sure to take safety precautions because you will be working with gas and electricity. 

Switch the thermostat to heat mode and set it to 80 degrees. Now find the pilot valve on the furnace and on/off handle, turn the handle to “off.” 

Now, locate the pilot light; it should be near the gas burner tube. Ignite the flame and switch the handle to pilot, and hold it for 35 seconds. 

Once the pilot ignites, switch the handle to “on.” If this method does not work, repeat the procedure and wait for 60 seconds instead of 35 seconds. 

So the thermocouple gets warm enough to signal the pilot light to turn on. If you repeat this method five times and the water heater pilot light won’t stay lit, other issues might be the culprit.

Claim The Warranty

Many water heaters flaunt a 1 or 2 years warranty. If your water heater pilot won’t light during this period, you can contact the manufacturer and get this problem resolved. 

This is tremendously beneficial because they will replace any malfunctioned parts or the heater wholly.

Hire A Professional

Unique Benefits Of A Tankless Water Heater

Suppose your device’s warranty period has finished and you have made all requisite checks and modifications as mentioned in this guide. In that case, it is the ideal time to hire a professional plumber. 

Many homeowners might consider it a last option; you should understand that most folks cannot handle DIY projects well. Also, you will be working with gas and electricity, so you should be extra cautious. 

Employing an expert might cost additional charges, but this route will keep you and your family safe, which should be your top priority. 

On the flip side, hiring a professional plumber guarantees that you don’t damage anything, which will definitely cost more to troubleshoot. 

A handyperson can detect an impending issue and give some tips to prevent it.


If the water heater pilot light won’t stay lit, various reasons can lie behind it.  The most common issues are thermocouple, lack of combustible air, thermostatic control or gas valve, pilot tube, flex tube, etc. 
The recommendations in this article should help you troubleshoot these problems or help you understand the actual cause of the issue. If nothing seems to work in your favor, you should call a professional plumber to fix the pilot light.

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