Tankless Water Heater Maintenance: Protecting Your Investment

Dec 7, 2023


Welcome to Scott Harrison Plumbing, your premier home services contractor specializing in top-quality plumbing solutions. In this article, we will guide you through the essential steps for maintaining your tankless water heater. By following our expert tips, you can ensure the longevity and efficiency of your system, protecting your investment for years to come.

Why is Tankless Water Heater Maintenance Important?

As responsible homeowners, we all understand the significance of regular maintenance in keeping our appliances and systems in optimal condition. The same holds true for tankless water heaters. These modern marvels provide a continuous supply of hot water while taking up minimal space. However, without proper care and upkeep, their efficiency may decline, and their lifespan could be shortened.

Step-by-Step Tankless Water Heater Maintenance

1. Consult the Manufacturer's Manual

Every tankless water heater model is unique, so it's crucial to refer to the manufacturer's manual specific to your unit. The manual contains detailed instructions for maintenance, including recommended procedures, intervals, and potential troubleshooting tips.

2. Turn Off Power and Water Supply

Prior to performing any maintenance tasks, ensure that the power and water supply to your tankless water heater are turned off. This is a crucial safety measure to avoid accidents and potential damage to the unit.

3. Flush the System

Over time, mineral deposits, sediment, or debris may accumulate within your tankless water heater, hindering its performance. To flush the system effectively:

  1. Close the water supply valves entering and exiting the unit.
  2. Connect a hose to the cold water isolation valve.
  3. Place the other end of the hose in a drain or bucket.
  4. Open the cold water isolation valve, allowing water to flow through the system.
  5. Flush the system for about 20 minutes to remove any accumulated debris.
  6. Once flushed, close the cold water isolation valve and remove the hose.
  7. Open the hot water isolation valve and check for any leaks.

4. Inspect the Venting System

The venting system plays a crucial role in proper operation and safety of your tankless water heater. Inspect the vent pipes for any signs of corrosion, obstructions, or damage. Clear away any debris or nests that may have accumulated. If you notice any issues, it is advisable to consult a professional for further assistance.

5. Check Pressure Relief Valve

The pressure relief valve ensures the tankless water heater does not exceed the recommended pressure limits. To check the valve:

  • Locate the pressure relief valve on the unit.
  • Place a bucket underneath to catch any water that may be released.
  • Lift the lever on the valve for a few seconds and then release.
  • If water flows freely, the valve is functioning correctly. If not, you may need to replace it.

6. Clean the Filter

Most tankless water heaters feature a built-in filter that prevents debris from entering the unit. Regularly cleaning the filter will ensure optimal performance:

  1. Locate the filter housing on your tankless water heater.
  2. Remove the housing and take out the filter.
  3. Rinse the filter under clean water to remove any accumulated debris.
  4. Once clean, re-insert the filter into the housing and secure it back in place.


Proper maintenance is key to maximizing the performance and lifespan of your tankless water heater. Following our step-by-step maintenance guide will help protect your investment and ensure uninterrupted hot water supply. If you require any professional assistance or have specific concerns, don't hesitate to reach out to Scott Harrison Plumbing, the trusted name in home services, contractors, and plumbing. With our expertise, you can enjoy the benefits of a well-maintained tankless water heater for years to come.