How to light a gas water heater

Don't worry, you won't blow yourself up.

Alina Bradford CNET Contributor
Alina Bradford has been writing how-tos, tech articles and more for almost two decades. She currently writes for CNET's Smart Home Section, MTVNews' tech section and for Live Science's reference section. Follow her on Twitter.
Alina Bradford
3 min read

If you're water won't heat up, the pilot light on your water heater may have blown out. Lighting a water heater is simple, no matter what type you have. 

Most newer models of gas water heaters have a simple ignition switch. In just a few steps the water heater is lit, no problem. If you've moved into an older house, though, you many have the kind of water heater that needs to be lit manually. Here's how to light both types of water heaters.

Do you have a manual water heater?

There's a simple way to tell if you have an automatic or manual gas water heater. Look at the box sticking out of the side of the water heater that has two different dials. If it is an automatic, it will have a small ignition button next to the big On/Off/Pilot dial. If it's a manual, there won't be a button.


The On/Off/Pilot dial is typically on the top of the box while the temperature dial is on the side. This automatic water heater has a green ignition button by the  On/Off/Pilot dial.

Taylor Martin/CNET

How to light an automatic water heater

The first step is turning off the gas by first looking for the knob labeled On/Off/Pilot. You'll want to turn the knob past Pilot to the Off position. Let any built-up gas that may be in the system dissipate for five minutes.

Now, it's time to start the lighting process. Turn the water heat dial to Low and the On/Off/Pilot dial to Pilot. Then, turn the On/Off/Pilot dial downwards and push the igniter button at the same time. Let go of the igniter button, but keep pressing the Pilot dial downward for around 30 seconds. You should hear a "whoosh" sound when the gas is lit.

If you take off the little door below the ignition box, there will be a little window you can peek into to see if the there is a flame. If it's lit, finish up by putting the door back, turning the dial from Pilot to On, and turning the water temperature dial from Low to the setting you like. If it isn't lit, you'll need to start over right away to prevent gas build-up.

How to light a manual water heater

To light this type or water heater, I suggest grabbing a long barbecue lighter. The pilot will be a little tricky to reach otherwise.

First, take off the plate that is below the box with dials on the side of the water heater. There may also be an inner plate that you will need to slide to the side. Then, you should see a pipe(s) leading to a burner.

Next, turn the knob on the box labeled On/Off/Pilot past Pilot to the Off position. Then wait for five minutes to let any remaining gas dissipate. Turn the water temperature dial to Low and the On/Off/Pilot dial to Pilot. Push the On/Off/Pilot dial downward with one hand while lighting the barbecue lighter with the other.

Quickly hold the barbecue lighter over the end of the pipe by the burner. The flame should light instantly. Keep pressing the Pilot dial downward for around 30 seconds and turn the dial from Pilot to On. Then, finish by putting the plates back over the burner hole and set the water temperature dial to your desired temperature.

Important: If the burner doesn't light within a few seconds, start the process over again. If you keep trying for a longer period of time, gas can build up and cause an explosion.

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