How To Service Tankless Water Heater?

To service a tankless water heater, begin by turning off the power supply and shutting off the water valves connected to the unit. Then, remove any accumulated debris, flush the system with vinegar or a descaling solution, and clean the inlet filter screen.

Finally, check the burner and igniter for any signs of damage or buildup, and ensure that all connections are secure before restoring power and water flow. A properly maintained tankless water heater will provide reliable and efficient hot water for your home.

How To Service Tankless Water Heater?


Understanding Your Tankless Water Heater

Tankless water heaters have gained popularity in recent years due to their ability to provide hot water on demand while saving energy and space. Understanding how these efficient appliances work is essential for proper maintenance and servicing. In this section, we will explore the different types of tankless water heaters, how they function, and the benefits they offer.

Types Of Tankless Water Heaters

There are two main types of tankless water heaters:

  • Electric tankless water heaters: These units use electrical elements to heat the water as it passes through the system. They are generally smaller and easier to install, making them a popular choice for apartments or smaller households.
  • Gas tankless water heaters: These systems utilize natural gas or propane to heat the water. They typically have a higher flow rate and can handle a larger demand for hot water, making them suitable for larger households.

How A Tankless Water Heater Works

Tankless water heaters operate differently than traditional storage tank water heaters. Here’s a simplified breakdown of the process:

  • Water flow triggers ignition: When hot water is required, a flow sensor detects the water flow, triggering the ignition in gas units or the activation of electrical elements in electric units.
  • Heating the water: As the water flows through the unit, it passes over a heat exchanger. In gas units, a burner heats the heat exchanger, while electric units activate heating elements. The water absorbs heat from the exchanger, raising its temperature.
  • Continued heating if necessary: If the desired hot water temperature is not achieved instantly, the unit will continue heating the water until the set temperature is reached.
  • Instant hot water delivery: Once the water has reached the desired temperature, it is ready for use. Unlike tank water heaters, there is no need to wait for a storage tank to fill up before hot water is available.

Benefits Of A Tankless Water Heater

Tankless water heaters offer several advantages over traditional storage tank water heaters. Here are some key benefits to consider:

  • Energy efficiency: Tankless water heaters only heat water when needed, eliminating the energy wasted in constantly reheating a stored supply of water. This results in significant energy savings and lower utility bills.
  • Endless hot water supply: With a tankless water heater, there is no risk of running out of hot water. It provides a continuous supply, making it ideal for households with high hot water demand or for multiple simultaneous uses.
  • Space-saving design: Compared to bulky storage tank water heaters, tankless models are compact and take up less space. They can be mounted on walls or installed in smaller areas, freeing up valuable floor space.
  • Longer lifespan: Tankless water heaters typically have a longer lifespan than traditional water heaters. With proper maintenance and regular servicing, they can last up to 20 years, adding value and longevity to your investment.

Understanding the different types, functioning, and benefits of tankless water heaters is crucial when it comes to servicing and maintaining these efficient appliances. Whether you opt for an electric or gas unit, the on-demand hot water, energy savings, space-saving design, and extended lifespan make tankless water heaters a compelling choice for many households.

Signs That Your Tankless Water Heater Needs Servicing

Is your tankless water heater not performing as efficiently as it used to? If you’re experiencing decreased hot water flow, inconsistent water temperature, or strange noises coming from the water heater, it may be time for a service. Ignoring these signs can lead to bigger problems down the line.

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Here’s what you need to know:

**decreased hot water flow:**

  • Check for clogged filters: Over time, mineral deposits can accumulate and clog the filters in your tankless water heater. This can result in reduced hot water flow. Regularly cleaning or replacing the filters can help maintain optimal performance.
  • Inspect for pipe obstructions: Blockages or obstructions in the water pipes can also restrict the flow of hot water. Examine the pipes leading to and from your tankless water heater to ensure there are no kinks, bends, or other hindrances.
  • Flush the system: Sediments and minerals can build up inside the tankless water heater, causing a decrease in hot water flow. Flushing the system once or twice a year with a descaling solution can help remove these deposits and improve performance.

**inconsistent water temperature:**

  • Check for error codes: Tankless water heaters often have built-in error code systems that can indicate issues with the unit. If you’re experiencing inconsistent water temperature, check the display panel for any error codes and consult the manufacturer’s manual for troubleshooting steps.
  • Inspect the heating elements: The heating elements in your tankless water heater may deteriorate or become faulty over time. If they are not functioning properly, it can lead to fluctuating water temperatures. Contact a professional technician to inspect and replace the heating elements if necessary.
  • Adjust the temperature settings: Sometimes, inconsistent water temperature can be a result of incorrect temperature settings. Make sure the temperature settings on your tankless water heater are properly adjusted to meet your desired hot water requirements.

**strange noises from the water heater:**

  • Check for loose components: Loose parts within the tankless water heater can cause rattling or banging noises. Inspect the unit for any loose screws, bolts, or connection points. Tighten them if needed to eliminate the noise.
  • Descale the unit: Mineral deposits can also cause strange noises in the tankless water heater. As mentioned earlier, flushing the system with a descaling solution can help remove these deposits and reduce the noise.
  • Contact a professional for deeper issues: If the strange noises persist even after troubleshooting the above steps, it may be a sign of a more significant problem. It’s advisable to consult a professional technician who can diagnose and repair any underlying issues with the water heater.

Remember, regular servicing and maintenance of your tankless water heater can prolong its lifespan and ensure optimal performance. Don’t ignore the signs of needing servicing, as addressing them promptly can save you from costlier repairs or having to replace the unit altogether.

Diy Steps To Service Your Tankless Water Heater

Tankless water heaters are a convenient and efficient way to ensure a constant supply of hot water in your home. To keep them running smoothly and extend their lifespan, regular maintenance is crucial. By following these simple diy steps, you can service your tankless water heater and prevent any potential issues.

Let’s dive in!

Step 1: Turn Off The Power And Gas Supply

  • First and foremost, ensure your safety by turning off the power supply to the tankless water heater. Locate the circuit breaker or fuse box and switch off the corresponding breaker.
  • Next, find the gas supply valve connected to the heater and turn it off. This will prevent any accidental ignition or gas leaks during the servicing process.

Step 2: Clean The Air Intake Filter

  • Locate the air intake filter, often located at the bottom or on the side of the unit. Remove the filter carefully.
  • Rinse the filter under running water to remove any dust, debris, or buildup that may have accumulated over time.
  • Allow the filter to dry completely before placing it back into the unit.
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Step 3: Flush The System To Remove Mineral Buildup

  • Mineral deposits can obstruct the water flow and affect the efficiency of your tankless water heater. Flushing the system regularly helps to remove these deposits.
  • Attach a hose to the cold water inlet and place the other end into a bucket or drain. Ensure the hose is securely connected.
  • Open the pressure relief valve and turn on the cold water supply, allowing it to flow through the system for approximately 20 minutes. This process will flush out any mineral buildup.
  • Close the pressure relief valve and remove the hose once the water runs clear.

Step 4: Inspect And Clean The Combustion Chamber

  • The combustion chamber is responsible for heating the water and can accumulate soot and debris over time.
  • Carefully remove the cover panel to access the combustion chamber. Use a soft brush or vacuum cleaner to clean away any dust or debris.
  • Ensure all components are securely placed back before continuing the servicing process.

Step 5: Check For Leaks And Replace Faulty Parts

  • Inspect the tankless water heater for any signs of leaks. Check the connections, valves, and fittings for any visible damage or water drips.
  • If you discover any leaks or identify faulty parts, it is essential to replace them promptly. Consult the manufacturer’s manual or contact a professional if needed.
  • Regularly checking for leaks and replacing faulty parts will help prevent potential water damage and ensure the optimal functioning of your tankless water heater.

By following these simple diy steps, you can service your tankless water heater effectively and keep it running smoothly for years to come. Regular maintenance is key to maximizing its efficiency and lifespan. Remember to always prioritize safety and consult professionals for any complex issues.

Keep your hot water flowing consistently and enjoy the convenience of a well-maintained tankless water heater.

When To Call A Professional For Tankless Water Heater Service

If you own a tankless water heater, it’s essential to know when it’s time to call a professional for servicing. While some minor maintenance tasks can be done by homeowners, certain complex repairs and installations should always be handled by an experienced technician.

Additionally, considering warranty considerations and hiring a qualified professional can ensure that your tankless water heater is functioning optimally. Let’s delve into these factors in more detail below:

Complex Repairs And Installations

  • Repairing or replacing the heat exchanger requires advanced technical knowledge, as it is the heart of a tankless water heater.
  • Flushing and descaling the system may seem simple, but improper handling can cause damage or void the warranty.
  • Handling gas lines and electrical connections for installations or repairs should only be done by a qualified professional to ensure safety.

Warranty Considerations

  • It’s crucial to familiarize yourself with the warranty terms and conditions provided by the manufacturer.
  • Attempting diy repairs or hiring an unqualified technician can void the warranty, leaving you responsible for all future expenses.
  • Professional servicing, as recommended in the warranty, is often the best way to maintain coverage for your tankless water heater.

Hiring A Qualified Technician

  • Research and choose a reputable and experienced technician who specializes in servicing tankless water heaters.
  • Check for licenses, certifications, and positive customer reviews to ensure their expertise.
  • A qualified technician will have the necessary knowledge and equipment to diagnose and fix any issues accurately.

Remember, a tankless water heater is a complex system that requires proper maintenance and occasional professional servicing. By understanding when to call a professional, considering warranty conditions, and hiring a qualified technician, you can ensure the longevity and efficient operation of your tankless water heater.

Don’t hesitate to reach out to a professional when needed, as it’s better to be safe than sorry.

Tips For Maintaining Your Tankless Water Heater

Regularly clean the air intake filter:

  • Ensure the proper functioning of your tankless water heater by cleaning the air intake filter regularly.
  • A dirty or clogged filter can restrict airflow, leading to decreased efficiency and potentially causing the water heater to overheat.
  • To clean the filter, follow these steps:
  • Turn off the power to the water heater.
  • Locate the air intake filter, usually found on the bottom or side of the unit.
  • Remove the filter and gently clean it with a brush or by rinsing it with water.
  • Allow the filter to dry completely before reinstalling it.
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Check for leaks:

  • Regularly inspect your tankless water heater for any signs of leaks.
  • Leaks can occur in various locations, including connections, valves, or the unit itself.
  • If you notice water pooling or dripping around the water heater, address the issue immediately to prevent further damage.
  • Check the following areas for leaks:
  • Connections: Inspect the fittings and connections for any signs of water leakage. Tighten any loose connections or replace faulty parts as needed.
  • Pressure relief valve: The pressure relief valve is designed to release excess pressure. Check if it is dripping water, which may indicate high pressure or a faulty valve. Consult a professional for assistance if needed.
  • Internal components: If you suspect a leak within the unit, it’s best to contact a professional technician to diagnose and fix the issue.

Monitor water pressure and temperature:

  • Monitoring the water pressure and temperature of your tankless water heater is vital to ensure its optimal performance and safety.
  • High water pressure can put strain on the unit, leading to potential damage, while excessively high temperatures can cause scalding or overheating issues.
  • Here’s what you can do to monitor them:
  • Install a pressure gauge: Attach a pressure gauge to the cold water connection of the water heater to determine the incoming water pressure. Ensure it doesn’t exceed the recommended range stated in the manufacturer’s guidelines.
  • Check the temperature setting: Make sure the temperature setting is within the recommended range for your specific model. Adjust it if necessary to prevent the water from getting too hot.

Schedule professional maintenance annually:

  • Annual professional maintenance is essential to keep your tankless water heater in top condition.
  • Professional technicians have the expertise to perform thorough inspections, clean internal components, and address any underlying issues.
  • Some key maintenance tasks include:
  • Flushing the system: Clearing mineral deposits and debris buildup from the heat exchanger and internal components.
  • Testing pressure relief valve: Ensuring the valve is functioning correctly to prevent excessive pressure buildup.
  • Inspecting gas lines or electrical connections: Checking for any potential hazards or faulty connections.
  • Verifying proper ventilation: Ensuring the exhaust vent is clear of obstructions and functioning efficiently.

Regular maintenance of your tankless water heater will not only extend its lifespan but also help maintain its energy efficiency, ensuring hot water is readily available whenever you need it. By following these tips and scheduling professional maintenance annually, you can enjoy reliable hot water and peace of mind.


Regular maintenance and servicing are key to ensuring the longevity and optimal performance of a tankless water heater. By following the steps outlined in this blog post, you can easily service your tankless water heater and avoid potential issues in the future.

Remember to turn off the power and gas supply before starting any maintenance work, and always refer to the manufacturer’s instructions for specific details. Cleaning the filter, descaling the heat exchanger, and checking for leaks are essential tasks that should be performed annually.

Additionally, being aware of signs of potential problems such as reduced water pressure or inconsistent hot water temperature can help you address issues before they become major headaches. Finally, it’s important to consult with a professional if you’re unsure or uncomfortable performing these tasks yourself.

With proper maintenance and care, your tankless water heater will continue to provide you with reliable hot water for years to come.


I am a mechanical engineer and love doing research on different home and outdoor heating options. When I am not working, I love spending time with my family and friends. I also enjoy blogging about my findings and helping others to find the best heating options for their needs.