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How to Light a Rheem Water Heater? – 5 Easy Steps

Fact checked by Stephen Conklin

how to light a rheem water heater

Indeed, many homeowners choose Rheem gas hot water heaters because these appliances are energy-efficient and convenient. And one of the most often asked questions about this brand is how to light a Rheem water heater.

You could be a first-time owner or a novice in troubleshooting a gas water heater with electronic pilot light or other ignition systems (i.e., spark ignition and hot surface ignition).

Learning to light or relight a Rheem water heater is a cinch, and we’ll share five steps to help you ace this task. Let’s start.

Table of Contents

Step-by-step to Light a Rheem Water Heater

What to Prepare

The Rheem water heater manual doesn’t list specific tools for lighting the appliance. Instead, the brand emphasizes safety precautions, including the following.

  1. Assess the surrounding air for gas odors.
  2. Use on the hands to operate the gas controls.
  3. Never ignite the pilot with a matchstick or BBQ lighter wand.

It’s worth noting the safety precautions cited above are specific to the Rheem Performance water heater. You might have different safety guidelines for other Rheem water heaters.

We recommend checking the owner’s manual for specific guidelines and instructions on lighting or relighting the gas water heater’s pilot. For instance, some versions might have a hot surface technology, requiring a different approach to lighting the appliance.

The steps we’ll share are specific for new Rheem water heater units with piezoelectric (or spark) ignition systems.

Step 1. Stop gas flow to the water heater.


The Rheem owner’s manual should provide a detailed guide on stopping gas flow to the water heater. It might even include drawings on the correct component to manipulate.

  1. Look for a small box on the gas water heater’s side and note a gas supply line on one side. Most Rheem water heaters have a single knob on the box for controlling gas flow and adjusting the thermostat.
  2. Hold the control knob and rotate it counterclockwise until the pointer is in the OFF mark.

Step 2. Wait at least five minutes.


Rheem is very peculiar about this step. Its manual states that homeowners must not light or turn on a Rheem water heater without reading its safety information.

  1. Wait five minutes after closing the gas control knob to allow complete dispersion of gas molecules.
  2. Bend close to the floor and try sniffing the area for gas odors.
  3. Abort this task if you notice even a whiff of gas.
  4. Avoid touching and operating any electronic appliances and switches if you sense gas. Contact the gas supplier using a telephone or mobile phone outside the house. The fire department is next in line if the gas supplier isn’t available.

Step 3. Open the water heater’s “outer door.”


Here’s another step Rheem is quite particular about. You can only execute this step if Step 2 yielded no signs of gas in the water heater room.

  1. Check the gas water heater’s outer door or access panel and see if it has screws.
  2. Remove the hardware with a screwdriver and secure the screws for refastening afterward.
  3. Look below the thermostat/gas control knob for a button. This button is Rheem’s piezo-electric spark generator.

Step 4. Light the Rheem water heater.


The following actions will help you ignite the Rheem water heater pilot light.

  1. Twist the Rheem water heater’s control knob until its pointer is at the “PILOT” mark.
  2. Press and hold the control knob and push the spark igniter several times while watching the heater’s status indicator LED. Stop depressing the igniter button once the LED starts blinking.
  3. Look through the water heater’s sight glass window and check for a bluish flame in the pilot.
  4. Repeat Steps 1 to 3 if the status indicator LED doesn’t blink after 90 seconds and you don’t see a flame in the pilot.

Contact the gas supplier or a water heater technician if the pilot light doesn’t turn on after several attempt cycles.

Step 5. Finish up.


You can wrap things up once you complete the pilot light ignition process. The procedure is just the reverse of everything you did.

  1. Release the control knob from its depression. It should pop right back up. If not, turn the knob to OFF and contact the gas supplier or a water heater technician.
  2. Return the outer door panel and secure it with screws, if any.
  3. Rotate the control valve to the desired water temperature level.

Here’s a YouTube video describing the steps for lighting a Rheem water heater’s pilot.

Troubleshooting Rheem Water Heater Ignition Problems

Some issues can make the process seem challenging or ineffective. Here’s how to troubleshoot Rheem water heater ignition problems.

  1. Pilot light doesn’t stay lit – A defective or worn-out thermocouple can make the pilot light not stay lit. Although you can replace this component yourself, Rheem advises owners to hire a professional because gas water heaters are somewhat complex.
  2. Pilot light flame is orange and weak – This sign reflects a dirty pilot tube. Rheem doesn’t want you to open the “inner door,” so you can only call a professional to remove the soot and other buildups in the pilot tube.


How to light a Rheem water heater might seem an odd question for seasoned owners of gas-powered water heaters. However, it’s a valid concern for first-time owners and homeowners experiencing water heater ignition issues for the first time.

Thankfully, Rheem’s gas water heaters are convenient. Even troubleshooting ignition problems are never a concern. However, we must emphasize the value of reading the owner’s manual. It’s your roadmap to a safer and more efficient gas water heater use from Rheem.

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