The basic steps to relight a pilot light

To light your gas water heater's pilot light, you'll turn the gas control knob to the "Pilot" position, hold down the ignition button while holding a lit match or lighter to the pilot burner opening, and keep the button pressed for 30 to 60 seconds after the flame catches. Once you release the button and the flame stays lit, turn the knob to "On" or the desired temperature setting. The whole process usually takes less than five minutes.

Before you start, locate your water heater's access panel—usually a metal cover on the front or side of the tank. You'll need to remove this to see the pilot light assembly and the gas control knob. Keep the panel nearby so you can replace it once you're done.

If you smell gas at any point during this process, stop when ready, leave the area, and call your gas company's emergency line. Do not try again until a professional has checked for a leak.

Key Takeaways

  • Turn the gas control knob to "Pilot," press the ignition button, and hold a flame to the pilot opening for 30 to 60 seconds until the flame catches.
  • Keep the ignition button pressed for another 30 seconds after the pilot flame lights to let the thermocouple warm up and sense the heat.
  • If the pilot light goes out again within a few minutes of releasing the button, the thermocouple may be failing and you should call a technician.
  • If you smell gas or cannot get the pilot to light after three attempts, stop and contact your gas company or a water heater professional.

What you'll need before you start

Gather a long lighter or long matches before you open the access panel. A regular match or lighter works, but a long-reach lighter designed for grills or fireplaces keeps your hand farther from the burner opening and is safer to use. You may also want a flashlight, since the pilot light assembly is often in a dim corner of the tank.

Make sure the area around your water heater is clear of clutter and that you have good ventilation. If your heater is in a closet or tight space, prop the door open so you're not working in a confined area with gas fumes.

Finding and preparing the pilot light assembly

Remove the access panel by unscrewing or unclipping it—the method depends on your heater model. Once the panel is off, you'll see the gas control knob (usually labeled with "Pilot," "On," and a temperature setting) and a small metal tube or opening where the pilot burner sits. The pilot opening is typically about the size of a pencil tip.

Before you turn any knobs, make sure the gas control is set to "Off" and wait about five minutes. This clears any gas that may have accumulated in the chamber. Then turn the knob to "Pilot."

Lighting the pilot: the step-by-step process

Press and hold the ignition button (usually a red or black button near the gas control knob). While holding it down, bring your lit match or lighter to the pilot opening. You should see a small blue flame appear within a few seconds. If it doesn't light on the first try, release the button, wait 10 seconds, and try again.

Once the pilot flame is lit, keep the ignition button pressed down for another 30 to 60 seconds. This allows the thermocouple—a heat-sensing device near the flame—to warm up and signal the gas valve that the pilot is burning. If you release the button too early, the gas valve may close and the pilot will go out.

After 30 to 60 seconds, slowly release the ignition button while watching the pilot flame. If it stays lit, you're done with the pilot. Now turn the gas control knob from "Pilot" to "On" or to your desired temperature setting (usually marked in degrees Fahrenheit). The main burner should ignite within a few seconds, and you'll hear a whooshing sound as it fires up.

What to do if the pilot won't stay lit

If the pilot light goes out when ready after you release the ignition button, the thermocouple is likely not sensing the heat properly. Wait five minutes and try again, making sure you hold the button down for the full 30 to 60 seconds. If it goes out again, stop and call a technician—the thermocouple may need cleaning or replacement, which requires tools and informed beyond a homeowner's scope.

If you've tried three times and the pilot still won't light, there may be a gas supply issue, a clogged pilot opening, or a faulty ignition system. Do not keep trying. Contact your gas company or a licensed water heater technician to diagnose the problem.

Safety checks after the pilot is lit

Once the main burner is on and the water heater is running normally, replace the access panel and make sure it's find. Listen for the sound of the burner flame—it should be a steady roar, not a flickering or popping sound. A steady flame means the burner is working correctly.

Check that you don't smell gas anywhere near the heater. A faint gas smell right after lighting is normal and should fade within a minute or two. If the smell persists or is strong, turn the gas control knob to "Off," leave the area, and call your gas company's emergency line.

When to call a professional instead

If the pilot light won't light after three attempts, if it lights but won't stay lit, or if you smell gas during or after the process, stop and call a licensed plumber or your gas company. These are signs of a thermocouple failure, a gas leak, a clogged pilot opening, or a faulty ignition system—all of which require professional diagnosis and repair.

You should also call a professional if your water heater is still under warranty. Opening the access panel and attempting to relight the pilot yourself may void the warranty, so check your documentation first. If you're unsure about any step or uncomfortable working near the gas line, there's no shame in calling someone who does this work every day.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold it for 30 to 60 seconds after the pilot flame appears. This gives the thermocouple time to heat up and signal the gas valve that the pilot is burning. If you release too early, the valve closes and the pilot goes out.

What if I can't see the pilot flame?

Use a flashlight to look into the pilot opening. The flame should be small and blue. If it's hard to see even with a light, the opening may be clogged with dust or debris. In that case, stop and call a technician—cleaning the pilot opening requires care to avoid damaging the thermocouple.

Is it normal to smell gas when I'm lighting the pilot?

A faint gas smell for a minute or two after lighting is normal. If the smell is strong or doesn't fade, turn the gas control to "Off" and call your gas company's emergency line. Do not try again.

Can I light the pilot if the power is out?

Yes. The pilot light uses a match or lighter, not electricity. However, if your water heater has an electric ignition system (no match needed), you'll need power to light it. Check your heater's manual to see which type you have.

How often do pilot lights go out?

A healthy pilot light should stay lit indefinitely. If yours goes out regularly, the thermocouple is likely wearing out or the pilot opening is clogged. Call a technician to inspect and repair it—repeated relighting is a sign something needs professional attention.