How to Light a Pilot Light on a Gas Water Heater

Instructions on how to light a pilot light on a gas water heater from Kenmore, Rheem, Bradford White, AO Smith, and other manufacturers.

Tips on lighting a pilot light when using the Honeywell, Rodgers-White, and Robertshaw gas control valves.

Every gas water heater has the lighting instructions found on the label attached to the heater. If such instructions are missing and you have to replace the pilot assembly or fix any other problem that requires re-lighting, follow the instruction found here.

How does the pilot light work?

Pilot light assemblyPilot light assembly

I will cover different types of gas control valves that are using a piezo-electric spark ignition system. The pilot flame is ignited by the electric spark generated when the igniter button is depressed. You can see the pilot flame through the sight glass window.

Once the pilot light is lit, it remains ON. The gas is also available to the main gas burner, and as long as there is a call from the thermostat, the pilot flame will ignite the main burner. If you require more info about problems and troubleshooting the pilot light, use this article.

Notes: If you want to learn how to light a pilot light properly, always follow the manufacturer's directions. One of these instructions says to fill the water heater completely, purge the air from the gas line, and never light by hand.

Use your hand to push or turn the gas control knob. Never use tools. If the knob is blocked and does not want to operate, stop, and call a technician - do not attempt to repair.

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Lighting the pilot light on the Honeywell gas control valve

As found on Kenmore Hydrosense, the Honeywell gas control valve has the control knob/thermostat, which allows you to choose one of the three positions: ON, OFF and Pilot, and adjust the temperature of hot water. Use the following step-by-step guide to light the pilot light on a Honeywell gas valve:

  • Turn the gas control/thermostat knob to OFF position.
  • The outer door should be temporarily removed to clear out any gases.
  • Turn the gas control knob to the "Pilot" position.
  • By pushing the knob in, gas will flow to the pilot burner only. Then press the piezo ignitor button. Sometimes it is needed to press it several times.
  • If the flame is lit, keep the knob depressed for half a minute until the flame heats the thermocouple and generates sufficient electricity to keep the gas valve open.
  • Release the knob, and the pilot flame should be lit. Keep in mind that the knob cannot be turned from ON to "Pilot" unless it is depressed.
  • To turn the gas water heater ON, put the knob into the ON position, and set the thermostat dial to the desired setting. The arrow usually marks recommended hot water temperature.
  • If the pilot didn't light, repeat the previous steps, but be careful to purge the gas from the combustion chamber by opening the outer door.

Lighting a pilot light on RobertShaw and Rodgers-White gas control valves

The following steps show how to light the pilot light on Robertshaw and Rodgers-White gas valves, which are similar to the above Honeywell gas valve:

  • Set the thermostat to its lowest settings.
  • Put the control knob to the OFF position. In some cases, it is needed to press the knob down slightly, to turn the knob from the "Pilot" to OFF position.
  • Wait for a few minutes to clear any gases. Remove the outer door.
  • Turn the gas control knob to the "Pilot" position.
  • Depress and hold down the pilot set button or gas control knob.
  • At the same time, press the piezo igniter until you hear the "click" sound.
  • Once the pilot light is ON, continue holding the pilot set button or gas control knob for a minute so that the flame can heat the thermocouple, and generate enough electricity to keep the gas valve open.
  • Release the button or knob, which should pop back up.
  • Turn the gas control knob to the ON position.
  • Set the thermostat to the desired temperature.
  • Your water heater should be running smoothly now.

As seen from the above instructions, lighting a pilot light on a gas water heater is not hard, but be careful when dealing with gas - it might be dangerous. That is why you should always consult the instructions on lighting the pilot light properly and safely. Or, contact your local water heater expert.

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