Water Heater Tankless No Power: Here’s The Solution!

Debarghya Roy

Tankless water heaters are a great alternative to traditional tank-based systems. They provide a continuous supply of hot water and save energy. But, sometimes they lose power. This article will look at possible causes and solutions.

  • The most common cause of power loss is an area power outage. When the electricity comes back, your tankless water heater will resume normal operation.
  • A malfunctioning control panel or electrical connections can also lead to power loss. If this is the case, it’s best to call a professional plumber or technician.
  • Certain models of tankless water heaters require battery backup. If it doesn’t work, the unit will lose power even when the main electricity supply is working. Fresh batteries can prevent this.

One customer experienced an unexpected power loss with their gas-powered tankless unit. They called Mastertech Plumbing for help.

The master technician Nate diagnosed the problem as a “cold water sandwich.” This happens when there are short bursts of cold water between periods of hot water usage. The solution was to adjust the flow rate by opening another tap slightly while using hot water. This gave them a steady and consistent flow of hot water.

Key Notes

  • 1. Tankless water heaters are a popular choice for homeowners due to their energy efficiency and space-saving design.
  • 2. In the event of a power outage, a tankless water heater will not be able to provide hot water as it relies on electricity to function.
  • 3. It is important to have a backup plan in place for hot water during power outages, such as a generator or alternative heating source.
  • 4. Regular maintenance and inspection of the tankless water heater can help identify any potential issues before a power outage occurs.
  • 5. Consider investing in a tankless water heater with a battery backup system, which can provide hot water even during power outages.
  • 6. It is advisable to consult with a professional plumber or electrician to ensure the proper installation and functioning of a tankless water heater.

Understanding the Issue of no power in tankless water heater

Ever experienced power issues with your tankless water heater? Hot water supply disruption can occur due to a variety of reasons, such as power outages or a problem with the control panel.

  1. First, check if there’s a power outage in your area. If there’s no outage, inspect the control panel of your tankless water heater. Look for any error codes or signs of malfunction.
  2. If nothing appears to be wrong, try resetting your tankless water heater. To do this, locate the reset button and press it for a few seconds. This may resolve minor glitches and restore power.
  3. In some cases, you may need professional assistance to fix the issue. Gas valves or pilot lights might need adjustment or replacement. Call a qualified technician to assess the problem and provide solutions.
  4. Consider investing in a backup battery system, to prevent future power outages from affecting your tankless water heater.

Pro Tip: Regular maintenance such as cleaning heat exchangers and checking gas burners can help prevent common issues.

Troubleshooting Steps if No Power in Tankless Water Heater Tankless

Troubleshoot a water heater tankless no power issue with these steps:

  1. Check Power Supply: Ensure the unit is plugged into a working power source.
  2. Reset the Unit: Find the reset button on the tankless water heater and press it.
  3. Call a Professional: If none of the above solved the problem, contact a qualified technician.

Keep up with regular maintenance and professional inspections to prevent future issues.

Remember, instructions differ based on models and brands. Consult your user manual or customer service for tailored instructions.

Stick to these troubleshooting steps and you can resolve power-related issues with your tankless water heater.

Note: This does not cover conventional tank-style water heaters or provide guidance for repairing gas valves or complex components.

Scenario-Based Solutions for No Power issue in tankless water heater

Analyze the problem to identify the cause and find the right solution. Let’s consider some common scenarios and solutions for restoring power to the tankless water heater.


  1. Check if there’s a power outage in your area. If so, wait for the power to be restored.
  2. Look for the reset button on the control panel and press it. This could fix minor electrical issues.
  3. Verify that the gas supply valve is open and providing enough gas.
  4. If the control panel isn’t working, consider replacing it or calling a technician.
  5. See if the tankless water heater has a battery backup. Replace/recharge batteries if needed.
  6. Inspect the electrical connections, wiring, and circuit breakers for damage or loose connections. Repair or replace these components.

Note: A professional plumber or technician may be needed in complex cases.

For optimal performance and longevity, regularly inspect and maintain your tankless water heater.

In conclusion, remember these solutions when your tankless water heater loses power. With the right approach, you’ll restore power quickly and save money.

When to Call a Professional

Having no power for your tankless water heater can leave you in hot water. But, don’t worry! Professional help is here. If basic troubleshooting doesn’t do the trick, it’s time to call an expert.

They have expertise in dealing with various tankless water heater brands, like Rinnai, Navien, Rheem, Stiebel Eltron, Noritz, Powerstar, and Tempra Plus. Plus, they can help with power outages and recurring errors.

For example, one customer encountered an issue with a lack of hot water. After trying troubleshooting on their own, they called our plumbing service. Our technician found the problem – a gas valve issue – and replaced the faulty part. The homeowner was back to taking luxurious showers in no time!

No matter the brand or model, professional help can save you time, effort, and costly mistakes. So, don’t hesitate to call an expert when faced with persistent problems or situations beyond your expertise.

Frequently Asked Questions

Q: Why is my tankless water heater not getting power?

A: There could be a few reasons why your tankless water heater is not receiving power. First, check if there was a power outage in your area. If not, make sure the unit is properly plugged into a functioning power source. Additionally, check the circuit breaker to see if it has tripped. If none of these seem to be the issue, it is best to call a professional technician to diagnose and fix the problem.

Q: What should I do if my Rinnai tankless water heater has no power?

A: If your Rinnai tankless water heater is not getting power, start by checking if the unit is properly connected to a power source. Additionally, ensure that the circuit breaker for the unit has not tripped. If both of these are fine, it is recommended to call a professional plumber or a Rinnai-authorized service provider for further assistance.

Q: Why won’t my Navien tankless water heater turn on?

A: If your Navien tankless water heater is not turning on, there may be a power issue. Check if the unit is properly plugged in and the power source is functioning. Additionally, make sure the circuit breaker has not tripped. If the problem persists, it is advisable to contact a professional technician or a Navien-authorized service provider.

Q: What should I do if my Rheem tankless water heater has no power?

A: If your Rheem tankless water heater is not receiving power, start by checking if it is properly connected to a power source. Verify if the circuit breaker for the unit has not tripped. If everything seems fine, but there is still no power, it is recommended to consult a professional plumber or a Rheem-authorized service provider for assistance.

Q: How can I troubleshoot a Stiebel Eltron tankless water heater with no power?

A: If your Stiebel Eltron tankless water heater is not getting power, ensure that it is correctly plugged in and the power source is operational. Check the circuit breaker and reset it if necessary. If the issue persists, it is advisable to contact a professional technician or a Stiebel Eltron-authorized service provider for further troubleshooting.

Q: Why is my Noritz tankless water heater not receiving power?

A: If your Noritz tankless water heater has no power, first check if it is properly plugged in and the power source is working. If the unit is getting power but still not turning on, there may be an internal issue that requires professional attention. Contact a licensed plumber or a Noritz-authorized service provider to diagnose and resolve the problem.


Tankless water heater systems can have power issues, like no electricity or a blackout. If this happens, check for simple causes like a circuit breaker being tripped or needing to reset the system. If that doesn’t work, it’s time to call a pro.

If a blackout affects the water heater, it could lose settings and require a reset. To do this, turn off the unit’s power, then flip it back on after a few minutes. If it still doesn’t work, get an expert plumber to help.

A control panel or wiring problem can also cause a power outage. Best to get an experienced technician to check it out.

To avoid future power issues, get a backup battery system. Plus, regular maintenance and servicing will spot problems early.

About the author

Debarghya Roy: A heating systems author, Passionate about energy efficiency and sustainability, Sharing insights and empowering readers through informative blog articles.