Water Heater Pilot Light: Troubleshooting and Fixes You Can Do Yourself

When your water heater pilot light, a small, continuous flame that ignites gas in gas-powered water heaters. Also known as standing pilot, it’s the heart of your gas water heater’s ignition system. If it goes out, you’re left with cold showers—and no magic button to fix it. Unlike electric models, gas water heaters rely on this tiny flame to trigger the main burner. No pilot light? No hot water. It’s simple, but when it fails, it’s frustrating.

Most of the time, a pilot light goes out for one of three reasons: a dirty or clogged pilot tube, a weak thermocouple, or drafty conditions near the water heater. The thermocouple, a safety sensor that detects whether the pilot flame is lit and signals the gas valve to stay open is often the culprit. If it’s worn out or coated in soot, it won’t sense the flame—even if it’s burning—and shuts off the gas. Replacing it costs less than $20 and takes 30 minutes. You don’t need to be a technician. Just turn off the gas, remove the old one, and swap it in. Same goes for the pilot tube, the small metal pipe that delivers gas to the pilot light. Dust, rust, or spider webs can block it. A thin wire or compressed air can clear it out. No tools needed.

But here’s what most people miss: if the pilot keeps going out after you relight it, it’s not just about the flame. It could be a failing gas valve, low gas pressure, or even a cracked heat exchanger letting air in. If you’ve tried cleaning the tube, replacing the thermocouple, and still no luck, it’s time to call in a pro. And if your water heater is over 10 years old, you’re not just fixing a pilot—you’re buying time. Most units this old are due for replacement anyway.

Don’t ignore a pilot light that won’t stay lit. It’s not just an inconvenience—it’s a safety risk. Gas buildup from repeated failed ignition attempts can lead to small explosions or carbon monoxide leaks. Always follow the manufacturer’s relighting steps. Never force it. And if you smell gas at any point, turn off the main valve, leave the house, and call for help.

Below, you’ll find real fixes from people who’ve been there. From how to test your thermocouple with a multimeter to why your water heater’s location near a window might be the problem, these posts cut through the noise. No fluff. Just what actually works.