On gas water heaters, the pilot light makes sure that there is always flame available when the burner needs to kick in and heat water. If you run out of gas, install a new water heater or have to shut it down for some reason, lighting the pilot is the first step to turn on a water heater. In fact, in the course of gas water heater troubleshooting, issues with the pilot light are fairly common yet easy to fix.
Before You Strike a Flame
Stand near the unit and take a deep breath. Do you smell gas or something like rotten eggs? If so, lighting the pilot is extremely dangerous and could cause an explosion. Turn off the gas line to your water heater and wait 1 hour. Turn the gas back on, wait 10 minutes, and sniff again. If the problem persists, call a qualified gas technician.
How to Light a Pilot Light on a Gas Water Heater
Older gas water heaters require you to use a flame to ignite the pilot, while newer models have a built in igniter. If you are not sure which type you have, look around the gas inlet line for a small glass window. This window is only found on newer models, because you actually have to access to the pilot light on older models. If you have run out of gas or the gas has been turned off, it may require several tries to get the pilot lit because all of the air has to be forced out of the line first.
Turn the temperature control to the lowest setting. Do not turn the unit off, only to the lowest setting. Turn the On/Off knob to PILOT. Near the bottom of the water heater, remove the outer access panel. Some models have a secondary access panel under the outer one, it is a safety panel to protect the pilot light and must be removed as well. You do not have to remove the access panel on all models, and the controls are outside the tank near the bottom of the unit.
If your unit has a pilot button, press and hold the button. If there is not a dedicated button, press the entire pilot control knob down. This button must be depressed until the pilot has been lit.
There is a small tube extending from the base of the water heater gas valve which leads to the pilot. Locate this line and follow it to familiarize yourself with the location that needs to be lit. Using a grill igniter or fireplace match, ignite the pilot light.
Locate the pilot igniter button somewhere near the On/Off knob. While holding down the pilot button, press the pilot igniter button. If you look through the glass window while doing so, you will see a spark generated as the igniter is pressed.
Completing the Job
If the pilot lights, hold the button for 20 seconds and release. If it does not stay lit, repeat the process. If the pilot will not remain lit after several tries, make sure you have gas in the tank and that there is sufficient ventilation. Some models have a filter that can be washed and replaced.
If the pilot lights, you can replace the inner access panel (if one is present), and then the outer panel. Turn the pilot control knob to the ON position and set the temperature control to the desired setting.