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How to Reset Rheem Water Heater? – 4 Easy Techniques

Fact checked by Stephen Conklin

how to reset rheem water heater

Rheem designs and builds its water heaters with exceptional quality, ensuring they will last many years. However, problems can still arise, requiring homeowners to master how to reset Rheem water heater units to kick-start the troubleshooting activity.

Although it sounds complicated, resetting a Rheem water heater is more straightforward than some homeowners think. The activity only requires a few hand tools and a basic understanding of how Rheem appliances work.

Continue reading to learn the detailed steps for resetting your water heater.

Table of Contents

Ways to Reset Rheem Water Heater


You have several options to restart a water heater from Rheem. Let us explore these techniques.

What to prepare

Resetting a Rheem water heater does not require any tool, except for a screwdriver or a hand tool to open the access panel and reach the reset button.

You might want to read the owner’s manual of your specific Rheem model to determine the reset button’s precise location.

Technique 1: Resetting a Rheem Electric Water Heater

Rheem makes high-efficiency electric water heaters and names them Performance Platinum.

According to the Rheem Performance Platinum troubleshooting guide, you only need four steps to reset ECO on Rheem water heater units. ECO is the Energy Cut Off and temperature limiting control (TLC).

Step 1. Turn off the heater and remove the access panel cover.

To reset a Rheem electric water heater, start by cutting all power to the Rheem water heater by turning off the circuit breaker.

Next, loosen the screws on the water heater access panel and remove the cover and any insulation. Rheem advises users not to remove the plastic thermostat cover.

Step 2. Press the reset button.

Look for the red reset button above the thermostat. Press and hold this button until you hear a click. The “clicking” sound is feedback, signaling the water heater is restarting.

Step 3. Put back the cover and turn on the heater.

Replace the insulation and access panel cover and re-establish power to the Rheem water heater.

Interestingly, pressing the red reset button will also reset Rheem water heater thermostat.

Technique 2: Resetting a Rheem Gas-powered Water Heater

Rheem also makes high-performance, energy-efficient natural gas-powered water heaters. The Rheem water heater lockout reset is nearly identical to resetting an electric unit.

  1. It requires opening the appliance’s access panel. Remove the panel cover and carefully pull out any insulating material.
  2. Next, look for the red Rheem gas water heater reset button, which should be above the thermostat.
  3. Press the red button and hold it steady until you hear a click telling you the unit is restarting.
  4. You can return the insulating materials to their correct position before securing the access panel cover.

Note: Sometimes, all you must do is turn off the electricity at the isolating switch and restore power to the switch to reset the ignition light.

Technique 3: Resetting a Rheem Tankless Water Heater


Rheem classifies its high-performance tankless water heaters as Classic Series models. Hence, we will describe how to reset Rheem Classic Series water heater units.

It is worth noting that these models reset differently, depending on whether they are electric or gas.

  1. Resetting a gas-powered tankless unit is similar to restarting a storage tank type. You only need to remove the access panel cover and insulation to press the reset button.
  2. Meanwhile, an electric tankless water heater from Rheem requires switching off the remote control and closing all hot water faucets and fixtures. The reset should complete after five minutes.

Technique 4: Resetting a Rheem Water Heater Flammable Vapor Sensor

Rheem gas water heaters feature many safety mechanisms to prevent accidental fires and similar issues. The flammable vapor sensor is a vital safety device that many homeowners overlook.

This tiny component detects fumes within the water heater’s vicinity. If the technology senses fire-producing vapors, it automatically sends an electrical signal to the gas valve to turn off the supply.

Unfortunately, sensor errors can occur, requiring a reset of the water heater’s flammable vapor sensor.

  1. Resetting this Rheem water heater component is as straightforward as unplugging the blower when starting the water heater. Wait about five to ten seconds before powering the blower back on.
  2. Observe for six temperature fluctuations before the dial settles on a temperature level. This event signals the completion of the reset.

You might also want to reset the water heater gas valve by turning the dial to the OFF position for five seconds before returning it to the ON position.

Resetting a Rheem Water Heater Error Code

Rheem water heaters have some of the most advanced technologies today. They have sensors that detect system problems and display the information on the screen as error codes.

For example, Error Codes 1L and 00 describe continuous combustion for an hour, while Error Code 05 indicates imperfect combustion.

You can also check your Rheem water heater troubleshooting manual for the other Error Codes and their respective solutions.

After fixing the problem, the Error Code might still show on the display. So how do you reset code errors?

Pressing the POWER button will clear or reset the Error Code.

Why is My Rheem Hot Water Not Working?

Troubleshooting a Rheem water heater involves determining why it is not working. You might want to consider the following scenarios to zero in on the potential problem. Hopefully, the solution only requires you to press the reset button on Rheem water heater units.

  1. Water is cold – The water heater might be turned off or the circuit breaker at the electrical panel is in the off position. These situations might explain a Rheem water heater not turning on.
  2. Water is too hot – The thermostat is set to the highest setting; there could also be a faulty thermostat.
  3. Low water flow rate – A broken pressure regulator or a closed main water shutoff valve might be the culprit.
  4. Pilot light is off – Inadequate gas supply to the water heater or a faulty or closed gas shutoff valve



Why does my Rheem water heater reset button keep on tripping?

Several reasons can explain why a Rheem hot water heater reset button continuously trips.

  • The water heater thermostat locks or stays in the ON position because of a failing thermostat. Thermostat failure can also produce inaccurate temperature readings, tripping the reset button.
  • The Energy Cut Off (ECO) system trips due to loose electrical wiring connections, leading to excessive heat.
  • A short circuit exists between the heating element and the ground, tripping the ECO.
  • High-Limit Switch malfunction can also trip the Rheem water heater reset button.
  • Frequent yet short hot water usage can trip the ECO.

How long must I wait after resetting before I get hot water?

Hot water is almost instantaneous after resetting a Rheem tankless water heater. It is a different story with storage tank units and their fuel source.

For example, a 30- to 40-minute waiting period is normal with gas-powered storage tank water heaters. Meanwhile, electric versions might need anywhere between 60 to 90 minutes to deliver hot water to the faucet.


Learning how to reset Rheem water heater units is a walk in the park. You only need to open the access panel, remove the insulating material, locate the red reset button, and press it until it pops a click.

The resetting process is nearly identical for all Rheem water heaters, except tankless electric models. You will also be surprised at how ridiculously easy it is to use this kind of Rheem water heater.

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