Is a Tankless Water Heater Making Noise? How to Reduce it!

why is a tankless water heater making noise

Suddenly you have noticed that your tankless water heater makes noise during running time. That is why you want to find the answer to this question: are tankless water heaters noisy?

You have already checked to find the exact problem but you can’t understand. So you are finding the solution on the internet for soundproofing the tankless water heater.

Still, you can’t understand whether the replacement of an old water heater is important or not. I think you should check some common problems that may create that noisy hammering sound.

Now, you can ask me what are the common problems for making ticking or clicking sounds?

Continue reading, if you want to know the basic reason for creating the sound of this type of machine.

After using it for a long time, some tankless water heaters make sizzling or knocking sounds for specific reasons.

So you should know the problems that I will try to tell in this post. But at first, you should be clear about the difference between the unit of the tank and the tankless heater.

N.B: If you have no time in hand, and you want to collect a new one, then my recommendation is that you should collect this type of brand new, reliable, and tankless water heater (automatic power is off when it finds any leakage) from the market.

Normally, there are two types of water heaters. One is a tank heater and the other is a tankless heater.

Tankless vs Tank Water Heater: Difference

tankless vs tank water heater

In the image, you can see that there is a storage tank of the heater for holding warm water and there is another type of heater which has no tank.

Heater with the Tank:

The temperature of cold water increases and is stored in the tank of that heating machine.

Tankless Heater:

There is no tank for storing heated water. Now, You have understood the basic difference between them. In this blog post, I will share the problem with solutions of only the tankless heaters.

So keep reading…

Why are Regular Tankless Water Heaters Noisy?

Like other people, you are also interested to know the answer to this question: why are some tankless heaters making noise?

There may be many reasons for the noise of this machine.

1. Reasons One: Loose parts may create any kind of sound.

2. Reason Two: When the outlet and inlet valves are not fully open (closed valves), there may create noise in that tank.

Fluctuations of water pressure may also be the reason for the noise. When there is some problem in the movement of the water flow (hammering) of that machine, it may create sound.

The problem of the thermostats (sensors) may be a reason for the unexpected pressure of the water of that heater.

3. Reason Three: During the running time of that heating machine, there may create vibration. This vibration is also the reason for creating noise.

4. Reason Four: Sediment buildup in the system and pipe
It creates the flow of water restricted, and may also create some noise.

How Loud are the Tankless Water Heaters?

Gas type of tankless water heater creates noise less than 90 decibels. (source)

A decibel meter is also important for measuring the noise of the tank. The noise level of these heaters varies for different heaters.

But when this type of heating machine makes an unexpected sound, then you need to repair it by following specific points. So there are some basic points below.

By knowing these points you can also try to soundproof that heating machine.

How to Decrease Sound (Noise) From the Water Heater (Tankless)

You should check the actual noise problem of that heating machine. If you can’t understand the main problem, then you can’t also reduce loud noises.

This is why at first you should concentrate on finding the exact noise source so that you can take an instant step for solving that issue.

Before starting corrective action, you should disconnect electricity from the power source.

1. Corrective Action for Reason One

If you have discovered any kind of loose parts of the current heater (machine), you should tighten it properly. For doing this you need to use an exact wrench.

If there are available loose parts of any kind of machine, they may create sound and finally go to a serious accident.

Find the loose parts and tighten them instantly, if you want a long-lasting water heater. You need to check to find loose parts regularly because any kind of joint parts may loose at any time.

2. Corrective Action for Reason Two

If you find the inlet and outlet valves are not fully opened, open them properly. For doing that you should rotate the taps of these valves counterclockwise so that they can fully open.

After doing that, if there is still exist sound, call a professional licensed plumber (a professional person for plumbing activities) for checking the total pipeline ways or water lines, drain valve and pressure of the water relief valve, aluminum anode rod, water pump, setting of water temperatures, inlet control valve, check valve, cold water supply lever, hot water outlet pipe, arrestor on valves, gas valve, dirty flow sensor, heat traps and dielectric nipple of the water heater.

3. Corrective Action for Reason Three

The vibration of any kind of machine is also the reason for creating noise. If you see that vibration is creating in your running heater, you need to take urgent steps for this.

If this heating machine is directly attached to the wall surface, you can add a rubber pad or foam mat (spacer) between the heating machine and the surface wall.

You can easily find the rubber pad in any local market. After adding the rubber pad, vibration can’t transfer to the wall. This is why vibration-related sound is not created around the side of that heating machine.

4. Corrective Action for Reason Four

The sediment layer is also the reason for creating the barrier of the water pressure. If there is some kind of barrier created inside the pipeline, sound may be created from it.

Now, You may have a question: what is common sediment?

sediment build up

Small particles may deposit (sediment build up) inside the pipeline area (area of water supply) where water flows.

After using it for a long time, some particles may be stored in that area. These stored particles are called sediment. Passing expanded hot water through the pipeline, it hits and pushes this sediment.

This is why a tankless water heater makes popping sounds or noises when hot water is turned on.

If you see that sediment is built in some portion of the pipe area and overall system, You should clear it urgently.


You should flush the total pipeline area with vinegar if you want to remove the mineral and sediment build-ups (deposits of the residue of calcium carbonate, magnesium, etc.)

The heating element may be affected by this sediment. In this case, you may use vinegar and a wire brush to clean.

N.B: After solving the noise issue of that heating machine, if you are still upset about bathroom noise, you can reduce that by applying acoustic material. For soundproofing a bathroom with a flush tank, you need to know the easy guidelines. By following that guide, most people are reducing bathroom noise. For filling the gap in the bathroom door, you can use selected weatherstripping and the most reliable acoustic sealant. For blocking the bottom gap of the bathroom door, you may use a sound-reducing door sweep. Besides, you may have a noise problem in your bathtub. If a bathtub creaks, you should take a step to reduce bathroom noise. If you also have a dryer that makes noise, you should fix it.

Thinking of using the new design tankless water heater?

My Viewpoint

In summary, I will tell you that you should clean that heating machine regularly. You should also inspect the loose parts and pipe straps; those are also the reason for the noise.

After finding any loose part, you should tighten it properly without delay. If you ignore the problem that is created in this machine, it may damage quickly in the future.

Regular maintenance or maintenance services of these types of heaters are also important for you. If you don’t know anything, you can read this whole post with concentration.

Here, I have shared the main basic noise problems and their solutions easily. If you are still unable to fix your tankless heater physically, you can contact a professional person and discuss the problems that I have already shared in this post.

You can read some more questions with answers that are in the FAQ section. I think you will get important notes within a short time.

FAQ: Tankless Water Heater is Making Noise

How Do You Fix a Humming or Buzzing Sound from this Heater?

If water flows in the heating element, it may vibrate and create humming noise or screeching sound. If you hear this type of sound, you should slightly tighten the elements. Most of the time, this problem is solved by following this method.

Are Tankless Water Heaters Quieter than Others?

Electric-type water heaters are quieter than gas water heaters. The gas furnace (gas burner) of the heater makes some noise that is not shown in the tankless and electric-type units of water heaters.

What is the Downside or Drawback of a Tankless Water Heater?

The installation cost of this type of tankless heater is higher than a heater with a tank. This heater needs to be attached to the wall surface.

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