If you have a gas water heater and suddenly have no hot water, a pilot light that has gone out is one of the most common — and easiest to fix — causes. Relighting it is a straightforward job that most homeowners can do in a few minutes. This guide explains how to do it safely, and what to check if the pilot won't stay lit.
Before You Start: Safety First
Gas is involved, so take a moment to be safe. If you smell a strong gas odor near the heater, stop — do not try to light anything. Leave the area, and call your gas company or a professional from a safe location. A faint gas smell right at the burner immediately after the pilot goes out can be normal, but a persistent or strong smell is not. Give any lingering gas several minutes to clear before attempting to relight.
Locate the Gas Control Valve
Near the bottom of the tank you'll find the gas control valve, which has a dial with settings usually marked On, Off, and Pilot. Nearby you'll see a separate igniter button (often red or black) on newer units, and a small viewing window where you can see the pilot flame.
Turn the Dial to "Off" and Wait
Turn the dial to "Off" and wait at least five minutes. This clears any gas that may have built up in the chamber, which is the single most important safety step in the whole process. Don't rush it.
Our Top Picks
Honeywell CQ100A1013 Universal Thermocouple
The most common cause of a pilot that won't stay lit. This universal thermocouple fits most gas water heaters and is an inexpensive fix.
KAIWEETS Digital Multimeter
Use a multimeter to test the thermocouple and confirm whether it — or the gas valve — is the culprit.
Scotch-Brite Heavy Duty Scour Pads
Handy for gently cleaning a dirty pilot assembly and thermocouple tip so the flame seats properly.
BIC Multi-Purpose Lighter
A long-reach lighter makes relighting the pilot on older manual units safe and easy.
Diamond Strike-Anywhere Matches
A simple backup for lighting the pilot when your igniter fails.
Final Editorial Verdict
Set the Dial to "Pilot"
After waiting, turn the dial to the "Pilot" position. Press the dial down (or the separate pilot button) and hold it — this allows gas to flow to the pilot only.
Ignite the Pilot
While holding the dial or pilot button down, press the igniter button repeatedly until the pilot flame lights. You should see it through the viewing window. On older units without an igniter, use a long lighter or fireplace match at the pilot tube while holding the gas button down.
Hold, Then Release
Keep holding the dial/button down for about 30–60 seconds after the pilot lights. This lets the thermocouple heat up enough to signal the valve that the flame is present. Release slowly — if the pilot stays lit, turn the dial to "On" and set your desired temperature. The main burner should kick on when the water needs heating.
If the Pilot Won't Stay Lit
If the flame goes out every time you release the button, the most common culprit is a dirty or faulty thermocouple — the small sensor whose tip sits in the pilot flame. It may just need cleaning, or it may need replacing (an inexpensive part). Other causes include a bent or misaligned thermocouple, a weak/clogged pilot orifice, or a faulty gas control valve. If cleaning and repositioning the thermocouple doesn't solve it, replace the thermocouple; if that fails, call a professional.
Conclusion
Relighting a pilot light is one of the simplest water heater repairs — turn the gas off, wait five minutes, set it to pilot, hold and ignite, then hold the button 30–60 seconds before releasing. If it keeps going out, suspect the thermocouple. When in doubt, or if you ever smell strong gas, stop and call a professional.