Ask a Plumber Why a Water Heater Pilot Light Won't Stay Lit
The pilot light flame on your gas water heater going out is a problem that is not only inconvenient but also frustrating to deal with. If the pilot light doesn't stay lit, you won't have any hot water, making even routine activities like taking a shower more hassle than usual. Naturally, you are perplexed. If the pilot light goes out, the good news is that this is a problem many homes experience, and the effort required to repair it is rather low.If the pilot light on your water heater won't remain lit and you don't know much about water heaters, allow us to walk you through the common causes of why your water heater isn't heating and the solution to this problem.
How To Light A Pilot On A Water Heater

Dirty Pilot Tube
It's possible for grime and other particles to accumulate in the pilot tube, which would then impede the flow of gas. Consequently, the pilot does not receive sufficient fuel to maintain his or her light. If the pilot won't light at all, this is another possible reason for the problem. Thankfully, a dirty pilot tube is a problem that can be fixed with the least amount of effort.All required is a needle, which may be inserted into the pilot hole to carefully clear away any debris. Completing this operation may require more than one attempt depending on the amount of debris present in the tube. The easiest way to determine whether or not this step was successful is to light the pilot and observe whether or not it lights up correctly and maintains its flame.
The Flex Tube Has a Kink in It
Fuel is delivered to the gas controller using the flex tube. There is a chance that the tube will become kinked, which will cause the flow of gas to be disrupted. Even though the pilot seems to be in good operating order, this is one of the most common reasons why the burner won't stay lit once it has been lit. Even though problems with thermocouples are more widespread, this one is simple to address and should be eliminated as soon as possible.Possibly the problem that can be fixed with the least effort, all you have to do is check the tube for any kinks and straighten it out. If the situation continues, you may be experiencing difficulties with the thermocouple.
There Is A Blockage In The Thermocouple.
Problems with the thermocouple can be rather prevalent, and this component is frequently the offender in cases where the water heater's pilot light continually goes out. This component is intended to assess whether or not the pilot light is lit by picking up an electrical signal transmitted by the heat generated by the pilot light.This signal can be disrupted when dirt particles get in the way, which might cause the thermocouple to incorrectly conclude that the pilot light has been extinguished. After then, it takes the necessary precautions to turn off the gas supply. Check that the thermocouple can be touched without feeling warm. After that, you will need to remove any dirt or grime from the surface by sanding it with a piece of sandpaper that has a very fine grain. This should guarantee that the component is functioning appropriately. If this procedure does not resolve the issue, however, a failed component can require thermocouple replacement.
Thermocouple That Has Been Damaged
This is a more serious scenario, as the part may need to be replaced. The sensor could have been bent so that it is now too far off from the pilot light, or the entire unit could have been rendered inoperable due to the damage.Check out the thermocouple here. When the pilot is turned on, the sensor should make a passing contact with the flame at the end. If it has become bent in a direction that is away from the flame, bend it back in a gentle manner. A multimeter examination is required for a thermocouple that appears in pristine condition and exhibits no damage symptoms. The reading ought to be higher than 20 MV. Any value lower than this indicates that the thermocouple has been compromised and has to be replaced.
Main Control Valve
Out of all the problems you can diagnose on your own, this is the one you want to steer clear of at all costs. You should exhaust all other possible alternatives before attempting to identify a faulty control valve. This is probably the culprit, with all other choices ruled out and the thermocouple displaying findings on the multimeter.The malfunctioning control valve can only be fixed by replacing it with a new one. There is no other solution. This can be more expensive than other do-it-yourself challenges and more challenging for people who lack prior knowledge of the job involved.
When All Else Fails
The typical homeowner should be able to diagnose the problem and implement a solution for all the factors described above. Despite your best efforts, there is still a remote possibility that the pilot won't stay on even after you've eliminated every possible explanation.In severe circumstances, the only viable remedy is to have a trained professional perform a comprehensive inspection of the water heater. In the worst-case situation, you could have to buy a whole new heater, but in the vast majority of cases, the issue can be fixed using the appropriate equipment and components.