How to Reset Tankless Water Heater – Simple Steps to Follow

Wondering about how to reset the tankless water heater? A tankless water heater works on demand. It’s a modern appliance that heats water on demand and it may sometimes run into an issue but the good thing is you can easily reset them without much hassle. They are tankless so water isn’t stored rather the heater when the tap is turned on. When the user turns on the tap the cold water travelling through the pipes is heated.

Do you often run out of hot water? You won’t face this issue anymore these winters if you have got a tankless water heating unit installed. These units are ultra-efficient so they save energy and also cut the installation & maintenance costs.

Tankless water heaters have low maintenance costs and this makes them super affordable. Most tankless water heaters have advanced technology and so are connected to remote control. This remote control displays the parameters of the appliance as well as the error codes. These codes decode the source, cause, and solution of the problem. The manufacturer provides the buyer with a manual that helps them understand these codes. If the code is not in the manual it can be searched online or a professional can help with the issue.

In this article, we have briefly explained how you can reset your tankless water heater no matter which Tankless Water Heater Brand you have. So Let’s get started.

Common Tankless Water Heater Issues

Here are some of the common issues that can arise with a tankless water heater.

No Hot Water Supply

The water running out of the faucet in this scenario is still cold. This is the most commonly faced issue and for this, you need to ask yourself how many appliances are you running at a time. If you have overloaded your unit then it might not be able to heat the incoming water and thus you face the problem. So turn off all the faucets and then turn on the system to check the functioning. Often this step solves the problem. Make sure nothing is blocking the pipes. They are free from dirt and dust. Most tankless water heaters have notification systems that inform about any blockage in the exhaust pipe.

Electric Supply Issues

If your tankless water heater runs on electric power then check the electric panel to make sure that it has not tripped. The electric supply to the unit is cut off at times to prevent any possible hazard. The issues that can cause the tripping of the power supply to the system are overheating of the water, leakage through pipes, or fault in the thermostat. If that’s the case then you need to reset the unit before it will start functioning again. In winter if you face any issue then make sure that the water is not frozen inside pipes.

How to Reset Tankless Water Heater?

Below is a step-by-step process for resetting your tankless water heater:

1. The first part of the job consists of opening the water heater box to do so you need to disconnect the electric supply to the tankless water heater. Tampering with a unit that’s connected to the electric supply is a big no-no. This can have very serious consequences. Begin with making sure that the appliance is in no contact with any electric supply. If the heater is connected to the electric supply using a cable then remove that cable or if it’s directly connected then turn the breaker off.

2. Most modern units are connected to the electric source using a cable so those who own a modern water heater need to unscrew the cables before opening up the appliance. Older units don’t have this system they are connected to the power supply directly so they need to be disconnected by turning the breaker off. If the breaker is already off then push it on. If it snaps back to off position then call an electrician cause the problem is with the breaker.

3. Now look for the metal plate at the bottom of your tankless water heater. This metal plate is held in place using screws and to remove it you need to loosen the screws. Try to locate your metal plate by looking through all sides of the water heater. This plate is usually held by 2 screws. Use a screwdriver to take out all screws one by one. Which type of screwdriver you need will depend upon your tankless water heater. Look for the detail in the manual whether your water heater needs a Philips or a flat head screwdriver.

4. Once all screws have been removed the plate can be then removed and the reset button can be accessed easily. Be careful when you have to loosen all the screws cause then the metal plate can fall to the ground and avoid so you need to be careful. Some water heaters might have a metal plate at the top. To remove the top metal plate to access the reset button.

5. After you have removed the metal plate the insulation pad will be visible. This pad has concealed the reset button. Pull out the insulation pad and put it aside for some time. If you feel the pad is wet then look for water leakage. If water is leaking through the water heater then resetting the water heater alone won’t fix the problem.

6. Now locate the reset button. It’s either red or reset is written on it. Now push the button inwards with force. The button might be firm if it has not been used for long. Keep the button firmly pressed until you hear a clicking sound. If you don’t hear a click then check that all the wiring of your water heater is working fine or not. But don’t worry much cause all heaters are not the same some might not make a clicking sound and that’s fine. Just reassemble your tankless water heater after you have pressed the reset button for 5 seconds.

7. Start reassembling your tankless water heater by first putting the insulation pad back in place. Just place the pad back in front of the reset button. Place the metal plate back in its place and screw it up carefully. Make sure the screws are not loose and all well tightened.

8. Plug the tankless water heater back into the socket so the unit is connected to an electric supply and your hot water will be running through the tap within a few hours.

Tankless water heaters are a great innovation but at times they might cause issues and are not working efficiently in heating the water. This is a sign that you need to reset your water heater. If you are a new user this process might be confusing for you but we have written this article to simplify the process and make it easy for you. Although the steps are pretty simple and you just need to open the tankless water heater outer covering and then after pressing the reset button close it again. Doing so will eliminate the problem and your water heater will be ready to use again but if you face this issue often then you need to look for other parts.

Why System Trips?

Sometimes the water gets too hot which causes the switch to trip.

This indicates that the thermostat is not functioning properly. It’s due to a thermostat fault in either the upper or lower heating element.

When to Reset the Tankless Water Heater

The reset button is a precautionary part of the water heater. It can trip off at times without any cause and so it’s safe to turn it on. Sometimes the reset button won’t turn on if

  • Wire issues

If the wiring is damaged then the electricity won’t reach the heater and so it won’t turn on.

  • Overheating

If the thermostat is normal and water gets heated above the set temperature this causes the breaker to trip off.

  • Malfunctioning thermostat

If the thermostat isn’t working right then the water won’t be heated and the circuit will turn off.

  • Use of reset button

The reset button is there to protect the appliance from bigger damage. The reset button avoids damage and is easy to reset within a few minutes. If the above process is not working for you try calling a professional as this indicates a big problem.

Different manufacturers might have different resetting settings so we’ll dig into the detail of how to reset some best-selling tankless water heaters.

Working of a Tankless Water Heater

When the water faucet is turned on cold water travels through the pipes. A gas element or an electric unit heats the water. This means a continuous supply of hot water on demand. As no tank needs to be filled so you can use water right away but this impacts the flow rate. Most water heaters can provide about 10 litres of water per minute. With multiple faucets at times, the water heater can get overused and it will cause water heating issues. The solution to this problem is installing multiple water heaters in a row so more water gets heated.

Right installation and maintenance improve the performance life of a water heater. Proper installation involves many factors like the climate, location, safety issues, and fuel type so it’s better to call a professional technician for installing the unit. If you want to install your unit yourself then it’s better to get some advice from the manufacturer. They can provide the instruction manual. Monthly maintenance extends the water heaters’ life and helps avoid dirt built up over time.

How to Reset Takagi Tankless Water Heater

How to reset takagi tankless water heater

Takagi has self-diagnostic units that automatically check whenever a problem occurs within the unit. It provides convenience to the owner and makes it easier to solve the problem for the technician. Whenever there is a problem a three-digit error code will appear on your remote control. If your water heater is not connected to a remote control then look for the green LED light on the computer board which will light up about 6 times.

Some common error codes are

  • 661 indicates an issue with the bypass valve. Check for limestone built up in the system.
  • 761 the temperature of the water is above 104 degrees Fahrenheit.

To reset the Takagi tankless water heater take off the front cover. Press the dip buttons 1 and 2. Hold the buttons for 5 sec. Turn the unit off for 5 sec and then turn it on. Wait for 2 minutes before turning the tap on and then enjoy the hot water.

How to Reset Rinnai Tankless Water Heater

How to reset rinnai tankless water heater

Rinnai offers a reliable and excellent performing water heater. It’s unlikely that you will face any issues with your water heating unit. If ever your display panel is showing some error code then follow the troubleshooting steps to solve the problem. Or you can ask professionals for help if needed.

Rinnai tankless water heater is useful for both home use as well as commercial use. If the unit is not functioning properly suddenly then reset it following some simple steps. Most of the Rinnai parts have a 5-year warranty so you can use the device carelessly for a long.

Rinnai is a well-known name when it comes to the tankless water heater. They have in this business for a long and they know their job. This means your chances of finding any fault are minimal. Your unit won’t produce issues often. The owner manual makes things easier as it elaborated the ways of troubleshooting. Different models have different specifications so it’s better to check the individual appliance details from the manual. If your appliance is under warranty yet then it’s better to get help from a professional. Opening the water heater on your voids your warranty. If you are confused and don’t know much about water heater getting help from a professional is always best in this case.

Rinnai display has many error codes from 02 to 79. This includes no error code. To reset the unit to factory settings look for connect button. Hold this button firmly until the LED light starts blinking white. Now release the button. Doing so will reset the module to factory settings. The factory settings will set the appliance to default which means it will remove all previous settings and wireless connections history. Whenever you change your wireless network reset the factory settings. Once the settings are set to default now choose the new system. When the connect button is pressed the led will turn white and later reboot and after all the settings are done the LED light will turn red.

How to Reset a Rheem Tankless Water Heater

How to reset Rheem tankless water heater

Rheem is a reliable brand that offers quality water heaters. They are efficiently good in their job and provide the best service to the user. Whenever any issue occurs the display panel will show an error code. You can check the error code chart to understand what the code means. It will tell you the cause and the possible ways of how to deal will the situation. It lists the ways of solving the common issues faced simply using this unit so the buyer will have a great experience.

All Rheem water heaters have a computer board. This board controls the parameters of the appliance. It is in control of the heating process. Rheem water heater is made using an electronic control board so they have a higher and better technology level. This appliance might have a remote control as well. These features make it easy to diagnose any issue and solve it later. Whenever any problem arises with your Rheem tankless water heater the LCD screen will display an error code that will tell you about what’s the issue with your water heater. Once you understand the error code solving the problem will be easy for you.

If you face disruption in hot water supply and can’t figure out any obvious cause try to reset the unit. Call customer service for help if you are not able to understand the process clearly.

The right way to deal with the situation is as follows;

  • Turn the hot water tap off
  • Turn the remote control off
  • Now wait for about 5 minutes
  • Turn the tankless water heater on
  • Turn the hot water tap on and see the results

If the error code is still showing and the water coming out of the faucet is not still hot try another solution. Turn the hot water tap and the remote control off. Make sure before moving onward that both of them are turned off. Search for the error code guideline online which will tell you about the problem in detail and help you solve it. If you fail to find anything related to the code online then call a professional technician to help you sort out the problem. Most often the codes are easily available and you can know the whole process of solving the problem by just knowing the code.

In case you can’t find the code details anywhere call the manufacturer with the following details.

  • Installation date of the unit
  • Model and serial number
  • Information regarding services done to date
  • Rest of the important details
  • The error code can be cleared by turning the power off if the controller is not fitted

How to Reset a Noritz Tankless Water Heater

How to reset noritz tankless water heater

Noritz has always managed to impress its buyers with high-quality products. The energy efficiency of their appliances is unmatchable. Yet despite so much effort into quality, no product is perfect. A tankless water heater can develop minor issues now and then but having an error code manual helps deal with the issues perfectly.

Error codes tell us about the problems that otherwise might not get noticed. They inform the buyer regarding the problem sooner and help prevent enormous repair costs later on. But the main problem is that the error codes might not be clear to the owner at all times.

If you don’t know about your error code then search for it online or use the manual to know more detail. Noritz water heater can be connected to a remote controller. Whenever there is any issue the error code will appear on its screen which you can read and then search about it for problem-solving. If you find it hard to fix the fault it’s always advised to get help from some professional.

The error codes displayed are always two-digit numbers like 10, 11, and so on. Display and operation lights start flashing at a time whenever a problem occurs. The elements of a tankless water heater are connected to an electronic board and one needs enough knowledge to solve any issue. Whenever any issue occurs with the functioning of your Noritz tankless water heater just go through the error code manual to read about the problem cause and solving strategy or reset the unit. To reset the unit you just need to press the reset button present on the front panel.

How to Reset Marey Tankless Water Heater

How to reset Marey tankless water heater

Marey has innovative tankless water heaters with 5 years warranty. These water heaters don’t cause any issues frequently but if you do face some issue an error code will appear on the screen. Depending upon the type of Marey tankless water heater you are using you might face different issues. Apart from the regular monthly maintenance if you face any issue with your Marey tankless water heater then contact an expert to deal with it. The most common problem most often faced by most people is the unit won’t start. There is no clicking sound as the heater starts. For this issue confirm that water supply connections to the unit are properly functioning and there is no leakage. Check the battery compartment for any issues. Check the micro switch that’s it’s functioning properly or not.

If the screen is not lighting up then check the electric connections. At times solenoid needs to be replaced by an expert. If you are not able to solve the issue try contacting customer care service for better guidance. For units with a warranty getting help from the manufacturer is always the most sought option cause otherwise the warranty will be voided.

After reading the complete article, We hope you will be able to reset your tankless water heater easily. And if you still face any issues with your tankless water heater, We recommend calling your local plumber to help you get the water heater fixed.

How to Reset Navien Tankless Water Heater

How to reset navien tankless water heater

Besides that, more errors also require resetting of the whole unit. Before resetting the Navien tankless water heater, you should understand these various error codes on display. When you can’t fix the error codes and there are more issues with your water heater, you should go for resetting. Sometimes, these codes won’t occur on display. It also means that it requires to be reset.

The easiest way to reset your Navien tankless water heater is to press the reset button. This button is located in the lowest corner opposite the on and off switch. You have to press the button, and your unit will start resetting. However, if you have tried all the error code solutions and reset the unit yet the problems occur, you should consult the Navien electrical support unit or hire a plumber.

Navien Tankless Water Heater Error Codes and How to Solve Them

Error Codes Malfunction

1. Error Code E001

It is caused by overheating of the unit.


You must clean the filter and then flush the heat exchanger to solve this issue. Ensure that the water circulates appropriately so that the unit does not overheat again. Sometimes you need to reset the unit.

2. Error Code E002

It is caused when there is low water pressure on the heating side.


Ensure that the unit receives enough water to complete the circulation this way, the water pressure will be equal in the whole unit.

3. Error Code E003

This error happens when there is an ignition failure in the unit and power failures.


The best solution for this problem is to ensure that the gas supply is proper and the ignitor produces a spark when the gas flows. Still, if there is any problem, you should replace the ignitor with a new one. Moreover, you should also reset the unit if the problem happens again.

4. Error Code E004

This error code occurs when the unit detects a false flame


To remove this error code, you must check that the ignitor is producing a proper spark and the central electric cord is connected to the unit in the right way.

5. Error Code E011

This error occurs when there is a high heat pressure on the unit.


To fix this error, you should first turn the unit off then drain the water inside it. After draining the water, you must turn on the unit. But if this error shows again, you must check the sensor and change it if necessary.

6. Error Code E012

This error code means that there is a flame loss.


You must check that the primary wire is connected to the unit property to solve this issue. Moreover, if the error persists, you must turn the unit off, remove the intake filter, and clean it properly. After drying, fix the filters, and the error will be no more.

7. Error Code E016

It is caused due to the overheating of the heat exchanger because of high temperature.


The best way to solve this problem is to adjust the temperature correctly. If it still happens, you should turn the unit off and then turn it on after 30 seconds. Check the cold water filter and strainers before you clean them. Also, flush the heat exchanger.

8. Error Code E030

This error is caused due when the exhaust overheats.


The best way to solve this problem is to clean the filter and flush the heat exchanger. Before that, you must switch the unit off for 30 seconds or reset your unit.

9. Error Code E046

This error means a problem with limit control and heat exchanger.


To solve this issue, you should thoroughly check the unit’s wiring. Look for a damaged wire, especially near the heat exchanger. If you find a broken wire, immediately replace it by calling the Navien technical support unit or resetting it.

10. Error Code E060

This error occurs when there is a problem with Dual Venturi Limit.


The best solution to clear this problem is to reset your Navien tankless water heater. For that, you must keep reading the article, and you will learn the easy way to reset.

11. Error Code E109

This error occurs when the fan motor is not working correctly.


To solve this problem, you must check the air filters and the fan motor. If they require cleaning, you must use running water and a toothbrush to clean deeply. Allow it to dry and then fix it back. But if the problem occurs, then you must reset it.

12. Error Code E110

This error is displayed when the unit faces blockage in the exhaust region.


Check the exhaust pipe for a blockage and clear the intake air filters by cleaning them with water. You can also use a toothbrush for deep and proper cleaning. After the air filters dry out, then you must fix them back. If the error persists, then reset the water heater.


Where is the reset button located on Navien tankless water heater?

The reset button is located near the power button( on and off switch). It is red, and you can easily find it on the unit. This button is used to reset the water heater when a problem is identified completely. Sometimes the metal plate that holds the thermostat should be removed to locate the switch. Moreover, you should avoid using this button randomly.

What temperature should a Navien tankless water heater be set at?

The maximum temperature to set on the Navien tankless water heater should be 120°F. It is the average temperature required. If the temperature increases 125°F, it is not safe to use because it will cause burns and even death from blistering. Therefore you should check the temperature first before you use the water.

Why is the tankless heater not heating water?

The tankless heater might not be heating water due to technical issues. Such as the exhaust being blocked or it might occur due to blockage of air supply. For that, you have to check the air supply and the exhaust. The air gets blocked, and the water remains cold. Some tankless heaters turn off automatically to prevent hazards.

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7 thoughts on “How to Reset Tankless Water Heater – Simple Steps to Follow”

  1. I just installed a tankless hot water heater in my RV. It works ok if you use the control panel to set the temperature for a shower. If you turn the cold water knob on any at all the heater starts cycling on off and then shuts off. I must have hooked something up wrong. Any ideas?

    • Please check which brand of water heater you have and then try resetting it. It that doesn’t work, we recommend getting it fixed from a professional plumber.

  2. I like the helpful info you provide in your articles. I will bookmark your blog and check again here regularly. I am quite sure I’ll learn many new stuff right here! Good luck for the next!


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