Don’t know how to reset a tankless water heater? Here’s the universal method that works for every tankless water heater, regardless of their brands and fuel types:
- Turn off the unit by pressing the power or On/off button.
- Turn off the electric supply to the unit at the circuit breaker. If it’s a gas-powered unit, cut off the gas supply by turning the gas control valve clockwise.
- Leave the unit unplugged for several minutes.
- Restore the power to the unit
- Turn on your tankless water heater and check it for proper operation.
Table of Contents
- How To Reset A Tankless Water Heater?
- Do Tankless Water Heaters Have Reset Buttons?
- What Causes A Tankless Water Heater To Need To Be Reset?
- Why Is My Tankless Water Heater Not Getting Hot?
How To Reset A Tankless Water Heater?
Here is the step-by-step procedure to reset a tankless water heater.
Turn Off The Water Heater
Turn off your tankless water heater first. Follow these steps to shut off a tankless water heater:
- Press the power or On/Off button on the front panel of the water heater to turn off the unit.
- Turn off the electric supply to the tankless water heater at the circuit breaker. In other words, flip down the circuit breaker for the water heater to cut off the electric supply.
- If you have a gas tankless water heater, turn off the gas supply to the unit. In this case, locate the gas control valve on the unit and turn it clockwise to turn off the gas supply.
Locate The Reset Button
The location of the reset button can vary based on the make and model of a tankless unit.
Some newer tankless water heaters have digital control panels. You can find the reset buttons on the control panel labeled as reset. For example, the Navien Tankless Water Heater has a reset button called Back on the digital control panel.
In some tankless water heaters, the reset button can be found inside the unit near the thermostat or heating element. I highly suggest referring to the manual or calling a professional if you don’t know where the reset button is.
Press the Reset Button Or Wait 30 Seconds
Once you locate the reset button, it’s time to reset the unit by pressing the reset button.
If you have a Navien Tankless Water Heater, press the Back button on the control panel. When you press the reset button, it will begin the restarting process. It will take a few minutes to complete the restarting process. So, wait until the water heater comes on.
On the other hand, if your tankless water heater has no reset button, leave the unit in unplugged condition for 30 seconds. It will let the unit reset the minor problem.
Check for Diagnostic Codes
Once the tankless unit has restarted, check for errors or maintenance codes.
Each error code will be a combination of letters and numbers. Those error codes indicate specific problems. You can’t operate the water heater unless you resolve them.
Check the manual to see the meaning of each error code and follow the troubleshooting steps as remedy mentioned in the manual.
Restore Power To The Unit
Restore the power to the unit. Regarding this, plug in the power cord of the water heater. Alternatively, flip up the circuit breaker for the water heater to the On position. If you have a gas tankless water heater, turn the gas control valve counterclockwise to turn on the gas supply.
Turn On The Unit & Test For Proper Operation
If you see no error code on the display, it’s time to turn on the water heater.
Press the power or On/off button to turn on the water heater. If it’s a gas unit, press the priority button. Then, set the temperature by pressing the Up or the Down button to your desired setting.
Next, turn a hot water faucet for one or two minutes. It will help purge air from the lines and allow you to check output water temperature.
Do Tankless Water Heaters Have Reset Buttons?
No, every tankless water heater doesn’t have a reset button. For example, EcoSmart, Rinnai, And Noritz tankless water heaters have no reset buttons.
However, you can still reset those units. Regarding this, turn off the unit and cut off the electric supply by flipping down the circuit breaker. Leave the unit for 30 seconds or a few minutes in unplugged condition. Then, restore the power and turn on the unit. It will reset the unit.
On the other hand, some brands like Bosch, Navien, and Stiebel Eltron have reset buttons on their tankless water heaters.
Note: Not every tankless water heater from Bosch has a reset button. Bosch AquaStar 2700ES has a reset button on the front panel labeled as reset. For resetting other models, try the universal method mentioned in the introduction of this article.
On the Bosch and Navien Tankless Water Heaters, the reset button is located on the control panel. If you have a Stiebel Eltron Tankless Water Heater, you can find the reset button on top of each copper heating vessel.
To reset these units, press the reset button. It will help you reset the tankless water heater.
Nonetheless, Rheem Tankless Water Heaters have no reset buttons. However, some models of this brand have a set of dip switches and buttons inside the unit. Using those buttons, you can reset the unit.
What Causes A Tankless Water Heater To Need To Be Reset?
Several reasons are responsible for a tankless water heater needing to be reset. They are:
- Error Codes: When a problem occurs, your tankless unit will notify you about it by throwing an error code. You can erase the error code by resetting the water heater.
- Overheating: A tankless water heater will shut off automatically due to overheating. You can restart the unit by resetting it and making it ready to heat the water.
- After power outage: If you fail to turn on your tankless water heater after a power outage, a simple reset to the unit may solve this issue.
Why Is My Tankless Water Heater Not Getting Hot?
A tankless water heater will produce no hot water for several reasons, including:
- Insufficient Gas Supply: If the propane tank is empty or the gas valve is in the off position, the unit will not get enough fuel to ignite the burner.
- Improper Fuel or Gas Pressure: The tankless water heater won’t heat the water if you fuel a natural gas unit with propane or vice versa. Besides, improper gas pressure can prevent the unit from producing hot water.
- Low Flow Rate: Every tankless water heater has a minimum flow rate to initiate. If the flow rate is too low, the tankless unit will not activate.
- Clogged Exhaust: A blocked exhaust causes the unit to turn off because of a low air supply rate.
- Tripped Circuit Breaker: If the circuit breaker for the water heater gets tripped, the unit will receive no electric supply. As a result, you can’t turn on the unit.
You can browse through Tankless Water Heater Troubleshooting category to repair or troubleshoot a tankless water heater problem.
Sohel Rana is an expert writer (Of course, the owner and founder of this blog) on plumbing, HVAC, and appliance repair & troubleshooting. Since 2020, he has written on these specific topics, though his writing journey began in 2018.
