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The water heater’s pilot light doesn’t just ignite the gas. It also helps to maintain internal temperatures. When the pilot light won’t stay lit, the water heater can’t maintain the internal temperatures, which allow the water to cool off. Pilot light issues are some of the most common problems you may experience with a gas water heater.

4 Reasons Why the Pilot Light Won’t Stay Lit

A malfunctioning pilot light not only prevents your water heater from operating correctly, but it can also be an indicator of potential gas buildup. Here are the top four reasons why your pilot light won’t stay on. The first two are the most common.

A Dirty Pilot Tube

Sometimes your pilot flame won’t stay lit because of a dirty pilot tube. Dirt and grime can build up and block the flow of gas. A filthy pilot opening will cause the pilot flame to become a wavy yellow flame, which isn’t hot enough and can’t heat the thermocouple correctly.


If the pilot tube isn’t the problem, then check the thermocouple. A dirty, bent, or damaged thermocouple could be the culprit. The thermocouple is a small copper rod that the pilot light hits. Its job is vital because it’s responsible for shutting the gas valve if the pilot light goes out.

If the thermocouple is damaged or not working correctly, it could be dangerous because gas would still be released. After a while, the gas could collect in your office or home and become a health hazard.

However, if there’s an issue with the thermocouple, the safety valve will shut even if the flame is still lit.

If the thermocouple is damaged, then you need to have it repaired or replaced immediately.

A Kink in the Flex Tube

While not as common of a problem as the thermocouple, a kink in the flex tube is another possible reason for the burner not staying lit. The flex tube provides fuel via the gas controller to ensure a steady stream of gas. If the flex tube gets a kink in it, it can interrupt the flow of gas. A flex tube problem should be a quick and easy fix.

Main Control Valve

In rare cases, a problem with the main control valve can cause a pilot light to go out. All other possibilities should be ruled out before considering this as a possible cause. If the main control valve has gone bad, you’ll need to replace it.

A pilot light that won’t stay lit is frustrating. Not only does it prevent the water heater from operating correctly, but it can interrupt your workflow or business operations. If your pilot light won’t stay lit, call a plumber to diagnose and fix the problem.

Find the right water heater for your business or facility at Wallingford Sales. We sell a full line of top brand commercial water heaters, parts, and plumbing supplies. Shop our online catalog today. 866.977.2537

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