How Often To Descale Tankless Water Heater

How often to descale tankless water heater: If you live in an area where hard water can rarely be found, you are hassle-free from descaling your tankless water heating system.

But the main concerning issue is for those living in hard water zones or any area where the temperature is much higher than the average. In usual areas, you have to maintain your tankless system once a year.

But when it comes to the hard water zone, the hassle amplifies a little bit. So, in this article, we will talk about all the things regarding tankless water heating systems.

But at first, we have to know how it works and why it needs maintenance, and in the meantime, we will talk about how often to descale the whole system. So let’s jump right in.

Working Procedure of Tankless Water Heater

A tankless water heater does not contain any storage to keep the water. Instead, it heats water directly from the main water line of your house. So when you turn on the hot water tube, you basically turn on the tankless heater as well.

The system usually heats water using an element that is commonly known as a heat exchanger. This heat exchanger either works by gas or electricity.

So now that you have an essential prior to how tankless water heater works, let’s jump right into the topic, so why does it need maintenance?

Main Reasons Why Tankless Water Heater Needs Regular Maintenance

Scale gathers in the tank system much slower than in the tankless system. If you live in a hard water zone, you should have been a little bit more conscious of this factor named “hard water”.

Now, what is it? Well, hard water is a type of water that contains mineral in it. Predominantly, calcium and magnesium. These minerals build in the heat exchanger, and then they end up blocking the pathway. So water can no longer flow by the passage.

Over the time being, this reduces the lifespan of the heater and increases the energy cost.

In addition to this- the mineral buildup on the heat exchanger can cause immense damage. It also requires the system to be replaced at the end, which is not really worth enough. Moreover, the manufacturer will not accept any responsibility for this type of damage.

In a maintenance visit, the professional would descale the whole system, which is also known as sublime. This will make sure that there’s no buildup on your system’s passage. You should descale the entire system to a professional at least once a year. But there are a few cases where you have to descale it twice and more than twice a year.

Is It Necessary To Descale The Whole System More Than Once a Year?

You might have to descale the system twice a year if,

  • The area you live in is a hard water zone: No matter where you live, the water entering your heater is always filled with minerals. Yet, in some places, the water contains much more minerals than the average, which professionals declared as a hard water zone.
  • If you’re living in a hard water zone, your tankless system will require descaling twice a year.
  • Your tankless heater is set to a high temperature: If your water heater temperature is set massively high, it would be very risky and troublesome. In the meantime, the system might get damaged.
  • Many chemicals dissolve much faster with the presence of heat. So the hotter your water is, the faster scale builds around the passage or pathway. To omit this, check the thermostat of your tankless water heater to know what temperature it’s set to.
  • If the thermostat indicates much temperature than 120 degrees Fahrenheit, it’s high time to call a professional, descale the whole system, and clean the mineral built from the passage.


  • What Would Happen If I Set The Temperature Higher Than 120℉?

Ans: It is for user safety. All tankless heater comes with a maximum default temperature setting which is 120℉. If you increase the temperature, then your heating system could have been hampering a lot. Although, the filter inside the heater can be lost its percentage.

  • How Do I Know If There’s Hard Water In My Area or Not?

Ans: You can simply go to Google and search in this format- “name of the in which you live+hard water index”. You will find the answer very easily.

  • What Would Happen If I Don’t Flush My Heater?

Ans: The answer is easy- “your heater will lose its potencies”. If you don’t want this to happen, make sure that you flush the heater regularly. And do follow the security inspections (turning off the main electric line). Lastly, don’t forget to call a professional if there any complexity occurs.


We were talking about “How often to descale tankless water heater” as described above. If you check the heater regularly, there wouldn’t be many problems. Apart from that- as hard water affects the heater, you can also apply some basic home remedies. But, calling a professional is always the best decision.

As lime and scale build upon the passage of the heater, the heater should be flushed periodically. So, keep an eye on this too. If the flush stops working somehow, the heater will stop automatically and lose its efficiency as well.

During the maintenance period, make sure that the main power source of your house is turned off. Otherwise, major electric shocks can occur. Hope this “How often to descale tankless water heater” post helps you.

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