Why Does My Water Heater Pilot Light Keep Going Out?

First, a Word on Safety

If you smell gas, don't try to relight anything, and don't flip light switches. Get everyone out of the house and call Southwest Gas or 911 from outside. A pilot that goes out because of a gas leak is a very different problem from one that goes out because of a tired sensor.

If there's no gas smell, it's fine to follow the relighting steps printed on the label on your water heater. If it lights and then goes out again within a few minutes or a few days, something needs attention.

Why a Water Heater Pilot Light Keeps Going Out

Here's what I check, roughly in the order I usually find them:

• A worn thermocouple. It sits in the pilot flame and makes a tiny electrical signal. When it wears out, the gas valve thinks the pilot is off and shuts off the gas. This is the most common fix.
• A dirty pilot. Dust and soot can partly block the pilot opening, so the flame turns weak and yellow instead of a steady blue, and it doesn't heat the thermocouple well enough.
• A clogged flame arrestor screen. Most newer gas water heaters have a screen near the bottom that lets air in. In Arizona garages, it clogs with dust, lint and pet hair, and the burner starves for air.
• Drafts. A garage door opening on a windy day, a nearby fan, or monsoon gusts coming down the vent can blow a pilot out.
• A failing gas control valve. This is less common, but it happens, especially on older units.
• Gas supply or venting problems. A kinked flex connector, an undersized gas line, or a blocked vent can all cause trouble. A blocked vent is serious, because it can push exhaust back into your home.

Why Arizona Garages Are Hard on Pilots

Most water heaters in the Valley sit in the garage. That means dust storms, summer heat over 120 degrees, and a lot of stuff stored close by. I always suggest keeping at least a couple of feet clear around the heater and never storing gas cans, paint or cleaning products near it. Those fumes can be drawn into the burner, and on newer heaters the safety system may shut the unit down to protect you.

A Call From a Glendale Family

Not long ago, a family in Glendale texted me a photo of their water heater. The pilot had gone out three times in one week. They'd been relighting it each time and figured the heater was just getting old.

When I got there, the heater was only about six years old. The air intake screen at the bottom was completely matted with dust and dog hair, because the dog's bed was right next to it. I cleaned the screen, replaced a tired thermocouple while I was in there, and tested the gas pressure and the venting before I left. It's been fine ever since. Sometimes the fix really is that simple, but it's worth having someone look at the whole picture.

When It's Time to Think About Replacement

If your water heater is getting up there in years, a pilot problem might be a sign of something bigger. Rust around the burner area, water on the floor, or a failing gas valve on an older tank are good reasons to weigh replacement against repair. I'll always tell you honestly which way I'd go, and why. Our post on how long water heaters last in Arizona can help you think it through.

If replacement makes sense, the heaters we put in through our water heater installation service carry a 6-year manufacturer warranty.

Get Help With Your Water Heater Pilot Light

If your water heater pilot light keeps going out, we can usually find the cause in one visit, and we'll do a free whole-home plumbing inspection while we're there. Do It Right Plumbing has been family owned and operated since 2006, and every job is backed by our 1-year parts and labor warranty. You'll know the price before we start. Call 602-428-2585, or text a photo of your water heater and its label to 602-596-3013 for a free rough estimate. You can also read about our water heater repair service or visit our homepage. For emergencies, we're available 24/7.