Takagi Tankless Water Heater Filter Cleaning

Takagi Tankless Water Heater Filter Cleaning [9 Easy Steps]

This is a complete guide on Takagi Tankless Water Heater Filter Cleaning. 

In this article, I will walk you through 9 simple steps to clean the inlet water filter by removing dirt or debris accumulation. 

The best part is- I will also break down how to descale the unit as a bonus. So, let’s get started right here. 

Table of Contents

Takagi Tankless Water Heater Filter Cleaning [9 Easy Steps]

Takagi Water Heater comes with an inlet water filter. It won’t supply water to the unit properly if this filter gets clogged by debris or mineral deposits. 

So, it’s recommended to inspect the inlet water filter periodically, like every two to three months. If there is restriction in the inlet water filter, follow the below step-by-step cleaning procedure to clean the filter. 

1. Set the manual gas shut-off valve to the off position. 

2. Shut the electric power off to the unit for several seconds. Then, restore the power to the water heater again. 

3. After 30 seconds, turn the power off to your tankless unit. 

4. Close the inlet water valve. You must close both the inlet and the outlet water valves to separate the water heater if it’s a part of an Easy-Link or Multi-Unit system. 

5. Open every hot water faucet in your house. When the residual water flow has stopped, close all the hot water faucets. 

6. Get a plastic bucket or a pan to collect water from the unit’s large drain plug with a filter. If you installed isolation valves, just open the drains to drain the water. Otherwise, you need to unscrew the large drain plug to drain water out of your tankless unit. 

7. Wait several minutes to ensure you drain every single drop of water from the water heater. 

8. Locate the water filter within the cold inlet, unscrew it and remove the filter from the unit. Scrub the filter with a tiny brush to brush away accumulated dirt from the water filter. Then, rinse the filter clean water. Next, let the filter dry and reinsert the water filter back into the cold water inlet. 

9. Replace the drain plug back into its place and secure it with the nut. 

How To Descale Takagi Tankless Water Heater? [Bonus Tips]

Descaling the water heater every year or every six months is a must. Otherwise, scale formation will clog the heat exchanger. And the worst part is- damage from scale buildup is not covered by warranty. 

To descale your Takagi Tankless Water Heater, complete the following flushing procedure: 

Descaling map

1. Ensure you have the following pieces of flushing kit at your fingertips: 

  • A submersible pump
  • Cleaning solution
  • Water hoses
  • A plastic bucket 

2. Disconnect the water heater from the electric outlet. 

3. If you have installed isolation valves with drain ports, do the followings: 

  • Separate the water heater by closing both the incoming and outgoing isolation valves: C and D. 
  • Attach both the water hoses and the Pump to the drain ports of the isolation valves. Connect the outlet of the pump to valve B and the other hose from valve A to the bucket. 

4. Fill the plastic bucket with 5 gallons of diluted white vinegar solution. Then, place the pump into the bucket. 

5. Open the valves A and B. Then, turn on the submersible pump to let it circulate the cleaning solution through the unit for 45 minutes or an hour. 

6. Rinse the cleaning residue from the heat exchanger: 

  • Close both A and B valves
  • Open the D valve and run clean water through the PRV for 15 minutes.
  • Wash the filter after flushing the unit with fresh water. 
  • Once you flush the unit thoroughly, close both A and B valves and leave the C and D valves in an open position. 

7.  Finally, restore power to the unit. 


How often do you need to change the filter on a tankless water heater?

You should change the filter every six months if you have a tankless water heater. However, you can use another one or two months if the condition of the filter is good. 

Is there a filter on a tankless water heater?

Yes, there is a filter on a tankless water heater, which you can find within the cold water inlet. 

Do tankless water heaters need to be serviced annually?

Yes, you need to service the tankless water heater annually. Otherwise, parts like the heat exchanger and water filter will get damaged severely. In short, poor maintenance can reduce the overall life expectancy of a water heater. 

What is the maintenance on a tankless water heater?

Inspecting and cleaning the parts like heat exchanger, water filter, valves on a regular basis like every six month or a year is known as maintenance on a tankless water heater. 

What happens if you don't flush your tankless water heater?

If you don’t flush your tankless water heater, mineral deposits will make a home in the heat exchanger. It will reduce the efficiency of the unit. In the worst case, it may even damage the heat exchangers. 


Periodic water filter inspection is a must. If it gets clogged by debris or scale buildups, water will not be delivered into the unit properly. So, it’s a must to clean the water filter. Just follow the 9 simple cleaning procedure I mentioned and clean the water filter like a pro. It will help you operate the unit smoothly. 

Read Also:

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *