Maintenance of Tankless Water Heater

Through proper and regular maintenance of tankless instant water heaters, they offer optimal performance with efficiency over many years. Commonly known as on-demand water heaters may demand periodic maintenance almost every six month if you have hard water in your area or if you set your water heater at high temperature.  

Unlike traditional storage tank heaters, the on-demand water heaters do not come with a tank to keep water. As the water flows through the cold water pipe, the tankless heater heats water straight away. 

The tankless heater activates the moment when the faucet is on for hot water. The heat elements usually known as heat exchangers are responsible for heating water. 

Maintenance of tankless water heater tips and procedure

Why Is Maintenance Important? 

In order to enjoy the longevity of a tankless water heater, regular maintenance is a must. With a passage of time, the minerals accumulate inside the heating chamber of your tankless model which leads to rust and erosion. 

Consequently your tankless heater is out of order and water flows become slow due to the accumulation. Thus you need to either repair or replace the model which is cost-effective. So you need to flush the tankless heater and remove the minerals buildup annually.  

But regular maintenance of tankless heater ensures that your heater is working perfectly. Moreover, the last long gives you peace of mind. And you enjoy hot water when you need it. 

What Is Hard Water?

The water contains a high mineral content such as magnesium, calcium, and limestone. The worst fact is that it can damage the water applications including tankless units. 

When water flows through the heat exchanger, the limescale builds up inside the heater. This limescale affects the tankless heaters efficiency and [performance negatively. The insulation layer between water and heat exchanger overheats the water. 

In addition to this, the minerals accumulation clogs up the passage that carries the water which reduces the speed of flowing water notably. As a result it becomes very difficult for water heaters to deliver hot water efficiently. 

Most importantly, if you ignore the cleaning of the heat exchanger, it will not only shorten the heater’s life but also increase your energy bills. Furthermore, the damages caused by limescale are unrepairable. Sometimes the situation gets worse and you need to replace the whole unit. 

Regrettably, such damages do not come under warranty issues by the tankless brands. 

How Often Should I Maintain My Tankless Water Heater?

No matter how high the price of a tankless water heater is, every ongoing model demands regular maintenance. Even the Rinnai, Rheem, Ecosmart top line tankless models need to flush properly.  

The question arises: 

  • How to start?
  • What to do?

But nothing to worry about. I will explain the procedure in detail so that it will make it easy for you to maintain your tankless water heaters. 

Before going to start maintenance, you must read out the guide or manual book given by the brand at the time of purchase. Every tankless brand has suggested the frequency and what kind of maintenance is required for different parts. 

If you wish to learn more about different tankless brands and how they work, read the buyer’s guide of tankless water heaters in detail. 

Professional Maintenance

Professional maintenance is suggested to have better results. The certified plumber will descale the limescale skilfully occurring inside the heat exchanger and remove mineral heaps throughout the tankless heater. 

Annually maintenance in order to descale the buildup inside the water heater is recommended. But it could be twice if the area has high water. Because in such a situation, you need to set a high temperature for an instant water heater. 

The hard water contains a relatively higher mineral amount than normal water. Therefore, there is more limescale accumulation in the heating elements which needs to be removed once every six months. 

If you are unable to schedule the maintenance then nothing to worry. You need to simply contact the skilled plumber to plan the maintenance schedule. He would also suggest the frequency for maintenance services for you tankless.  

Do It Yourself Maintenance

To ensure the optimal performance and efficiency, you need to remove the mineral deposits. You can do it yourself if you have little plumbing skills. 

Let’s read out in detail.

Shut off your tankless water heater.

To do this, turn off either the main gas valve of gas instant heaters or the circuit breakers for your electrical appliances.

Close the three water valves on your tankless water heater.

  • By using this method, you will stop cold water from entering the water heater and hot water from escaping.
  • In a typical home, there are three valves: a cold water valve that is usually a blue color, a hot water valve that is a red color, and a third main valve which automatically runs the water into the house.

Pull the purge valve caps slowly off of the cold water valves and the hot water valves.

  • Small handles resembling a letter “T” are on the purge valves.
  • To prevent excess hot water from spraying out and coming into direct contact with your skin, this procedure is done to relieve any pressure inside the valves.
  • If you remove the purge port valve caps, there may be pressure, so it is critical to ensure that the hot water valve is shut off completely and safety is paramount.  
  • Each cap should be handled carefully in order to ensure the rubber washer sealing discs remain in place. Without this, the valve won’t operate properly.

Connect each of the three valves with a hose.

  • You can purchase hosing lines from any home improvement or water heater retailer if your tankless water heater manufacturer didn’t provide them. It is important that the hoses reach your water heater and bucket sufficiently.
  • The exact instructions for this procedure may be found in the manual provided by the tankless water heater’s manufacturer or through direct communication with the manufacturer.
  • You may need to use a sump pump and connect hoses to the tankless water heater so that these valves can discharge and flush water through hot and cold water valves depending on the circumstances.
  • The purge port valves must be turned perpendicularly to the cold and hot valve positions

Instead of chemical solutions, always clean your tankless water heater with undiluted white vinegar of 2.5 gallons (9.46 liters).

  • Chemical cleaning solutions may be especially harmful to your health since your tankless heater provides all the drinking water and bathing water in your home.

Ensure that you follow the manufacturer’s instructions for flushing and draining your tankless water heater.

  • You may have to wait up to 45 minutes for the procedure to be completed.
  • After the flushing process is complete, twist the “T” handles to close the purge valves.
  • Remove the hose from each water valve and disconnect it.
  • Reinstall the parts of the purge port valves into the purge valves.
  • Make sure that the rubber sealing discs inside the caps are completely and firmly tightened.

For more information on the proper way to restart your tankless water heater, refer to the manufacturer’s manual.

  • Depending on the type of tankless you have, rotating and opening the cold and hot water valves to ensure they align with the main valve leading into the house could be enough.

Let the air pass through the hot water pipe by slowly turning on the hot water tap.

  • Let the water run until it is running continuously without air escaping.
  • It may take up to three minutes to complete this procedure.

Daniel Adley is an experienced and skillful plumber having more than 20 years of experience. He is a skillful plumber who passionately repaired and optimized water appliances of large buildings, offices and homes. He would efficiently identify plumbing and maintenance issues.

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