Tankless Water Heater Maintenance Guide

Nov 3, 2023


Welcome to Scott Harrison Plumbing, your trusted home services provider specializing in plumbing solutions. In this comprehensive guide, we will walk you through the essential steps to effectively maintain your tankless water heater. Regular maintenance is crucial for ensuring optimal performance, energy efficiency, and long-lasting functionality. Let's dive into the details!

Why Is Tankless Water Heater Maintenance Important?

Tankless water heaters offer numerous benefits, including energy efficiency, unlimited hot water supply, and space-saving advantages. However, to fully enjoy these benefits, regular maintenance is essential. Neglecting maintenance can lead to reduced efficiency, increased energy consumption, and even costly repairs. By following these maintenance steps, you can extend the lifespan of your tankless water heater and enjoy uninterrupted hot water.

Tankless Water Heater Maintenance Steps

1. Turn Off the Power

Before starting any maintenance procedures, it is crucial to turn off the power supply to your tankless water heater. Locate the circuit breaker or switch dedicated to your water heater and switch it off. Safety should always be the top priority.

2. Flush the System

Over time, sediment and mineral buildup can accumulate inside the tankless water heater, affecting its performance. To flush out these deposits:

  1. Close the hot water valves and disconnect the power supply.
  2. Attach a hose to the flush port of the heater.
  3. Place the other end of the hose in a suitable drain or bucket.
  4. Open the pressure relief valve and allow the water to flow through the hose for about 20 minutes.
  5. Close the flush port, remove the hose, and restore the power and water supply.

3. Clean the Air Intake and Exhaust Vents

The air intake and exhaust vents play a vital role in the proper functioning of your tankless water heater. Dust, debris, or blockages can hinder its efficiency. Take the following steps to clean them:

  • Turn off the water supply and power to the water heater.
  • Use a soft brush or vacuum cleaner to remove any debris or dust from the vents.
  • Inspect the vents for any signs of damage or blockages.
  • Clean or repair any damaged vents before restoring power and water supply.

4. Check Pressure Relief Valve

The pressure relief valve serves as a safety measure to release excess pressure in the system. It is important to test and ensure its proper functionality:

  1. Locate the pressure relief valve.
  2. Manually lift the valve's tab to allow water to flush out. Be cautious of hot water.
  3. Observe if water flows freely and stops when you release the valve.
  4. If the valve doesn't function correctly, it may need replacement. Contact a professional plumber.

5. Inspect and Clean Water Filters

Most tankless water heaters feature inline water filters to prevent debris and sediment from entering the unit. Over time, these filters can become clogged, affecting water flow and heater performance. Follow these steps to clean the filters:

  • Turn off the power and water supply.
  • Locate the filters and carefully remove them.
  • Rinse the filters with clean water to remove any accumulated debris.
  • Inspect for any signs of wear or damage. Replace if necessary.
  • Reinstall the filters and restore power and water supply.


Regular maintenance of your tankless water heater is essential for optimal performance, energy efficiency, and durability. By following these outlined steps, you can keep your tankless water heater running smoothly for years to come. Remember, if you require professional assistance with tankless water heater maintenance or any plumbing issues, Scott Harrison Plumbing is here to help. Contact us today and experience our top-notch services firsthand. Trust us for all your home service needs!