The basic steps to relight a Rheem pilot light

To relight your Rheem water heater pilot, you will 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 the pilot stays lit on its own, turn the knob from "Pilot" to "On" (or the temperature setting if your model has one). 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 will need to remove this to see the pilot assembly inside. Have a long lighter or long matches ready; a regular match often will not reach far enough into the opening.

Key Takeaways

  • Turn the gas control knob to "Pilot" and press the ignition button while lighting the pilot burner with a match or lighter held at the opening.
  • Keep the ignition button pressed for 30 to 60 seconds after the flame appears so the thermocouple can heat up and hold the gas valve open.
  • If the pilot does not stay lit after you release the button, wait five minutes and try again—the thermocouple may need more heat.
  • If the pilot will not light after three attempts, or if it lights but goes out when you turn the knob to "On", the thermocouple or gas valve may need replacement by a professional.

Where to find the pilot light assembly on your Rheem unit

On most Rheem water heaters, the pilot assembly sits at the bottom of the tank, inside the access panel. You will see a small metal tube (the pilot burner) and a knob labeled "Pilot," "On," and sometimes a temperature setting. Next to or below the burner opening, you will see a small red or black button—this is the ignition button, sometimes called a piezo igniter.

If your Rheem has an electronic ignition system instead of a button, you will see a control panel with a digital display or a switch labeled "Ignition." In that case, follow the specific instructions on your unit's label, as the process differs slightly. Most Rheem models made in the last 15 years use the button system described here.

Turning the gas control knob and positioning the lighter

Locate the gas control knob on the front of your water heater. It will have three positions: "Pilot," "On," and usually a temperature dial. Turn the knob all the way to "Pilot"—this reduces the gas flow to a safe level for lighting.

Hold a long lighter or long match near the pilot burner opening. The opening is usually a small hole about the size of a pencil tip, located just below or to the side of the ignition button. Position the flame so it will reach into the opening when you press the button. You want the flame to be close enough to ignite the gas as it flows, but not so close that you burn your hand or the lighter itself.

Pressing the ignition button and holding it down

Once your lighter is positioned at the pilot opening, press and hold the ignition button. You should hear a clicking sound as the piezo igniter sparks. At the same time, move your lighter flame into the opening so the gas ignites. You may see a small blue flame appear at the burner.

Keep holding the ignition button down for 30 to 60 seconds after the flame appears. This is the critical step—the thermocouple (a heat-sensing device) needs time to warm up. Once it is warm enough, it signals the gas valve to stay open even after you release the button. If you let go too soon, the pilot will go out.

After 30 to 60 seconds, slowly release the button while keeping your eye on the flame. If the pilot stays lit, you have succeeded. If it goes out when ready, wait five minutes for the thermocouple to cool, then try again.

Turning the knob to "On" after the pilot is lit

Once the pilot flame is burning steadily on its own, turn the gas control knob from "Pilot" to "On" (or to your desired temperature setting if the knob has one). You should hear the main burner ignite with a soft whoosh sound. The water heater is now heating water normally.

Listen for the burner to stay on for at least 10 to 15 seconds. If it ignites and then shuts off, turn the knob back to "Pilot" and wait a few minutes. The thermocouple may not have been hot enough yet. Repeat the lighting process, holding the button longer this time.

What to do if the pilot will not light or will not stay lit

If the pilot will not light after three attempts, check that gas is reaching the unit. Make sure the gas valve on the line leading to your water heater is turned on (the handle should be parallel to the pipe, not perpendicular). If the valve is on and the pilot still will not light, the gas line may be blocked or the igniter may be faulty.

If the pilot lights but goes out as soon as you turn the knob to "On," the thermocouple is likely failing. A thermocouple that cannot hold the gas valve open will need to be replaced—this is a job for a licensed plumber or HVAC technician, as it involves working with the gas system.

If the pilot lights and stays on, but the main burner does not ignite when you turn the knob to "On," the problem is usually in the main gas valve or the thermocouple signal. Again, this requires professional service.

Safety reminders when working with your water heater

Never force the gas control knob or ignition button. If either feels stuck, stop and call a professional—forcing it can damage the valve or create a gas leak.

Do not leave the knob on "Pilot" for more than 15 minutes without lighting the pilot. Gas will accumulate in the chamber and create a hazard when you finally try to light it. If this happens, turn the knob to "Off," wait five minutes for the gas to clear, and then try again.

If you smell gas at any point, turn the knob to "Off" when ready, leave the area, and call your gas company's emergency line. Do not try to light the pilot again until a professional has checked the unit.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold it for 30 to 60 seconds after the flame appears. The thermocouple needs time to heat up so it can signal the gas valve to stay open. If you release too soon, the pilot will go out. If you hold it longer, that is fine—just do not hold it for more than two minutes.

What if I hear clicking but no spark?

The igniter button may be worn out or the igniter electrode may be dirty. Try cleaning the electrode with a dry cloth or pencil eraser. If clicking continues but no spark appears, the igniter likely needs replacement by a professional.

Can I use a regular match instead of a lighter?

Yes, but a long lighter is easier because it keeps your hand farther from the heat. If you use a match, light it first and then hold it near the pilot opening while pressing the ignition button. Be careful not to burn your fingers.

Why does the pilot light go out after I turn the knob to "On"?

The thermocouple is not hot enough or is failing. Try lighting the pilot again and hold the ignition button for the full 60 seconds before releasing. If it still goes out when you switch to "On," the thermocouple needs professional replacement.

Is it normal for the pilot flame to be small and blue?

Yes. A small, steady blue flame about the size of your pinky fingernail is normal. If the flame is yellow or orange, or if it flickers constantly, the pilot tube may be dirty or the gas mixture may be off—have a professional check it.