When a gas water heater isn’t heating water, chances are that the pilot light has gone out.
To see if it has, remove the access panel at the bottom of your gas water heater. This should reveal a viewing window through which you can see the pilot light. You may have to turn off the light and lay down on the floor to peer through the viewing window.
If you do not see the pilot light, you’ll need to turn it back on. Newer water heaters have an electric igniter switch to make it easy. There should be instructions printed on the side of your water heater to help you relight the pilot light, but in general, it’s done like this:
- Turn the gas knob to “pilot,” then press and hold it down. If your water heater has a second gas knob just for the pilot light, press and hold that one instead.
- While holding the gas button down, press the igniter button. This should produce a spark that will ignite the gas coming out of the pilot orifice. You should be watching through the viewing window while you complete this process, so you can see when the pilot light comes on. Darkening the room will help you see it more easily.
- Keep holding the gas knob down for a full minute so that the pilot light can heat the thermocouple, allowing it to produce the electricity it needs to operate the gas valve.
- After one minute, release the gas knob or pilot switch. Verify via the viewing window that the pilot light is still lit.
- If the pilot light goes out, repeat the process. If it stays lit, you can turn the gas knob to your desired temperature.
If your pilot light doesn’t stay lit, there may be debris in the orifice. To clean it, turn the gas knob to “off,” remove the bracket holding the pilot orifice and thermocouple tubes in position, and clean it with a stiff wire brush or poke a thin wire into it. Then replace the bracket and try lighting the pilot light again.
If the pilot light won’t light at all, make sure that the gas valve on the main gas supply line into your home is open. If you’ve recently had the water heater installed, there may be air in the gas line; to flush it out, hold down the pilot knob until you can smell the rotten-egg smell of natural gas. Release the knob and wait at least ten minutes for the gas to dissipate before you try lighting the pilot light again.
If neither of these solutions work, you might need to call a service technician to replace your thermocouple or your gas control valve. If neither of these is faulty, the problem could be low gas pressure, which you’ll have to address with your gas company.