Do Tankless Water Heaters Make A Lot Of Noise?

Bathroom, Beginner Info, Tankless Water Heater

Do Tankless Water Heaters Make A Lot Of Noise
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The simple and sweet answer would be, yes, a tankless water heater produces noise while it is operating but it isn’t loud by any means, that is, the noise coming out from your tankless water heater will not make you uncomfortable.

However, if your tankless water heater is making loads and loads of noise then the probability is very high that there is something wrong with it.

Don’t worry, in this post, we would be discussing the nuts and bolts of a noisy tankless water heater along with what needs to be done if you’ve encountered such a problem.

So, without any further ado, let’s begin…

I know quite a few of you would be inquisitive to know about the average level of noise for a tankless water heater, right?

Maybe you’re planning to upgrade from your traditional tank-styled water heater to an advance self-modulating tankless water heater like ECOSMART and want to be sure about the kind of operating noise that a tankless counterpart produces or whatever.

Trust me, we’ll cover the minutes of the things that we think will help you in making an informed purchase decision.

Does it make sense?

In general, a tankless water heater features two noisy elements, that is, a blower motor and a burner.

In the context of a conventional tank-styled water heater, the noisy elements remain the same.

So, in simple terms, when it comes to noise, both tankless and tank-style models will produce almost similar levels of decibels if NOT exactly.

Trust me, a premium brand tankless water heater will not produce more sound than an operating refrigerator so I don’t think noise should be a hurdle in making or breaking a buying decision.

But, in some cases, the noise coming out of your tankless water heater can be quite loud.

For example, the flue-purge at the end of the burn as the blower is working on maximum speed for a couple of seconds or even more.

Trust me, even the gas tankless water heater operates at quite low decibels which will NOT irritate your ears for sure.

In fact, even though you’ve installed the unit close to your master bedroom in the basement with the vent 5′ from the window, the probability is quite high that it will NOT disturb your sleep.

From my past knowledge and experience, all I can say is that the tankless water heater generally operates at a noise that is similar to an electric can opener or even a computer fan, nothing louder than that.

So, do you still think a tankless water heater is louder?

Do let us know in the comment section.

You can expect the operating noise of a tankless water heater to fall in the range of 45 to 65 decibels.

The quietest tankless water heaters operate at a noise level in the 45 to 52 decibels.

As the BTUs will increase, your tankless water heater will become louder.

For example, a tankless water heater will be quieter at 19,900BTUs as compared to 199,000 BTUs. irrespective of the types of brands or models.

Common Reasons Behind A Noisy Tankless Water Heater

Let’s have a quick look at some of the common reasons behind a noisy tankless water heater.

In the latter part, we would also be discussing the types of noises that you should be worried about.

So, keep reading 🙂

Any kind of noise coming out of your tankless water heater when it’s NOT operating is a point of concern.

In such a scenario, the best thing that you can do is take help from a plumber or a certified technician.

If you’re not sure about the source of the noise then don’t try to fix it on your own because it will do you more bad than good.

One of the common causes of noise could be a messy flow sensor which is responsible for controlling the amount of gas sent to the tankless water heater.

Most probably, the reason would be blocked or inadequate ventilation or even defective or poorly set pressure valve.

So, if you’re not sure about the components of a tankless water heater then taking help from a certified technician would be a better decision, indeed.

Another important parameter that can contribute to the louder noise is installation especially if you’re plan is either to mount the unit on the wall or enclose it in a protective box.

Even the location of installation matters a lot.

For example, if you’re planning to install your tankless unit close to the windows then it might disturb your sleep to some extent when ignited.

Moreover, if you’re planning to enclose it in a box then you must keep a track of its noise when the unit is heating the water as well as about its vibration against the wall/echoes within the box.

If your tankless unit is vibrating or echoing then you can definitely lower the noise by simply putting some rubber mat or foam between your tankless unit and the wall.

In the latter part of this post, we would be having an in-depth discussion on how to make your tankless water heater quieter?

Types of Noises that You Should Be Worried About

Well, not every noise is equally dangerous.

Some noises need to be handled quickly and in the best possible way to prevent any last-minute misadventure.

Let’s have a quick look at different types of noises that need quick fixing.

It’s really important for the house owners to be able to distinguish between a normal & an abnormal noise coming out of their tankless water heaters in order to fix the same if needed.


If your electric tankless water heater or any other variant is making a popping noise then the probability is quite high that sediment buildup could be the reason behind this nasty noise.

Are you aware of the fact that water in general consists of minerals that can aggravate corrosion?

And, as per my knowledge and experience, all I can say is, it’s just a matter of time until sediments will build up.

In some regions, the sediment buildup process would be slow and gradual while for other regions it would be fast depending upon the concentration of minerals and sediments in the water passing through the tankless unit.

The sediment buildup will lead to blockage of water, and as a result, you would hear a popping sound which simply means water is struggling hard to flow freely through the unit.

Furthermore, if your region is comprised of hard water then you don’t have an option but to deal with mineral deposits mainly consisting of magnesium and calcium.

It’s NOT only the annoying NOISE rather the performance of the unit is also adversely impacted by the accumulation of calcium and magnesium minerals.

So, to deal with water hardness, the best thing that you can do is to install a water softener.

Moreover, the unit needs to be flushed at least once every year.

Sizzling, Hissing, Ticking, And Crackling

Such sounds are the outcome of excessive blockage to the free flow of water inside the tankless unit.

And, if you’re hearing any one of these sounds, then the first thing that you need to do is to examine pressure relief as well as the temperature valve and see if it’s too much pressure.

On the other hand, Ticking could be the result of pressure fluctuation inside the unit.

The elements of the system need to be properly checked in order to get rid of such nasty and irritating noises.


Rumbling is a particular type of irritating noise that is produced by a tankless unit during the process of heating the water when it passes through debris and specks of dirt.

In simple words, such noise indicates the presence of excessive dirt in the unit which needs to be cleared at the earliest.

You might think it’s not harmful but at the same time, you need to understand it can definitely impact the performance of the unit and of course, not for good reasons.


Well, the sizzling sound coming out of your tankless unit simply indicates that water doesn’t flow into the unit in a hassle-free manner.

By examining the temperature and pressure relief valve you would be able to find the root cause behind the noise.

Moreover, sizzling is more prevalent in tank-style conventional water heaters.

But, what if I say, your gas water heater can also produce a sizzling sound.

If that is the case, then the culprit is none other than the condensation stand.

What actually happens is, when the water droplets are formed in the tank then their probability of landing on the burner is quite high.

So, if the heater becomes heated, it leads to a sizzling sound as soon as water touches it.


Humming noise coming out of a water heater is so irritating, isn’t it?

Frankly speaking, heaters that consist of the heating element on the top and bottom part of the heater are more prone to such noise.

In fact, when cold water enters the tank and roams around the unit, the top part will shake and make noise.

Though the hum is capable enough to frustrate and irritate anyone still it can’t wreck the heater or its components.

The good news is, fixing such irritating noise is quite easy, all you need to do is to make heating elements tighter.

Why Does My Tankless Water Heater Make So Much Noise?

Till now, you would’ve got an idea that a tankless water heater can become louder because of numerous reasons.

So, the best thing that you can do is to determine the cause of the sound and address the underlying issue.

When it comes to reducing the intensity of noise coming out of a tankless unit, the quick hacks include flushing the system with vinegar, tightening the loose parts, and most importantly, ensuring that the inlet and outlet valves are fully open.

And, you know what, the best part is, all the aforementioned maintenance activities can be expedited without any need for a plumber, interesting, isn’t it?

Identifying the Source of the Noise

First and foremost, you need to identify the source of the noise and then act accordingly.

By identifying the sound location, you would be able to determine the NEXT step that you need to expedite in order to get rid of the noise.

From my past experience, all I can say is that there are mainly five types of reasons behind such nasty noises.

Once you’re able to identify the type of noise, you can take the action accordingly.

The symptoms for each problem include:

Loose Parts

As mentioned earlier also, if you’re getting humming sort of noise from your tankless unit, then chances are quite high that it’s because of loose parts.

Restricted Water Flow

The noise produced due to blockage of water in the tankless unit sounds like a Screeching one so you need to be very careful and act accordingly in order to prevent any last-minute misadventure.

Sediment Buildup

If sediments are building up slowly and gradually in your tankless unit, then you would be hearing sounds similar to cracking or hissing.

And, in the worst-case scenario, when the sediments start breaking up from the heat, you would be hearing a sound similar to popping.

Water Pressure Fluctuations

A sudden fluctuation in water pressure produces ticking noise.


Due to vibration inside your tankless unit, you would be hearing sounds similar to ticking noise.

How to Reduce Noise From a Tankless Water Heater?

Well, depending upon the source of the noise, you would be applying the corrective action.

Let’s discuss each one of them in detail.

Noises Caused By Loose Parts

With the help of a wrench or a socket, you need to tighten any loose pieces present in your tankless unit.

Make sure that you’ve identified all the loose parts and acted accordingly in order to get rid of nasty and irritating noises.

Noises Caused By Restricted Water Flow

First and foremost, you need to ensure that the water inlet and outlet valves are in fully opened positions.

If that isn’t the case, then all you need to do is to rotate the taps counterclockwise until its fully engaged.

Well, if the sound continues, then, in that case, you may need to have a plumber inspect your water lines as well as temperature and pressure relief valve.

Noises Caused By Sediment Buildup

To be honest, sediment buildup is a slow and gradual process, and it definitely, doesn’t go away on its own, right?

However, getting rid of sediments is a quick, easy, and less time-consuming process, and the best part is, you can expedite the process on your own without the need for expert guidance.

Sounds, good?

All you need to do is to flush the system using vinegar in order to remove any kind of sediment buildup.

Don’t take sediment buildup lightly, in fact, in extreme cases, sediment buildup can bury the heating element inside an electric tankless water heating system.

Noises Caused By Water Pressure Fluctuations

In order to get rid of noises caused by water pressure fluctuations, all you need to do is to trace the sound’s source and tighten any loose straps holding down your pipes.

For the optimum result, you can also install spacers between the pipes and the walls to muffle any noises.

Noises Caused By Vibrations

If you’ve installed your electric tankless unit on the wall, then you need to install a foam mat or rubber between the system and the wall.

Moreover, if the unit is in an enclosed case, then you can insulate the inside of the case using audio insulation designed for automobiles.

Are Tankless Water Heaters Quieter?

In general, tankless water heaters produce very little noise which is almost equivalent to refrigerators operating in the next room.

Irrespective of the types of water heaters, they are known to produce some sounds which can become louder in the long run due to numerous reasons including sediment buildup, pressure fluctuation, etc.

However, by following the below-mentioned preventive steps you would be able to control the pitch of the noise.

It goes without saying, prevention is better than cure, isn’t it?

Moving further, I would be walking you through some preventive measures that will help you in preventing future noises.

Does it make sense?

  • Make it a habbit to check your propane tankless water heater or any other variant periodically for loose parts and do the needful as mentioned above
  • In order to prevent various types of noises caused by restricted water flow, you need to ensure that the inlet and outlet valves are fully opened at all times
  • Noises caused by sediments buildup is quite common in the hardwater regions and it’s a naked truth that you’ve to deal with it. All you need to do is to flush your water heating system atleast once a year if not more. Another solution would be the installation of a water softener system between your water supply and the water heater, interesting, isn’t it?
  • For effectively dealing with the noises that are caused on a frequent basis due to water pressure fluctuations, all you need to do is to periodically check for loose straps if any on the pipes that are connected to your tankless heating system. In order to prevent such issues to aggravate, I would recommend you to install spacers to the pipes
  • Noises that are caused by vibrations within the tankless unit are easy to deal with, simply, consider installing a mat or even an audio insulation when installing your water heater system instead of waiting until the sound becomes an issue


In this section, I would be responding to the queries related to doing tankless water heaters make a lot of noise in order to help you make an informed decision.

In case, I’ve NOT answered your question please feel free to reach out to us via the contact form of, and our team would be more than happy to assist you.

Does it make sense?

What does it mean when your water heater is knocking?

In general, knocking noise is caused due to accumulation of sediment, mineral deposits at the bottom of the water heater.

In layman’s terms, a reduced volume of water inside the tank forces the steam bubble to rise as the burners heat the tank resulting in a knocking sound.

Are Rheem tankless water heaters noisy?

Definitely, NOT…

A Rheem tankless water heater isn’t noisy at all.

However, it does produce some noise equivalent to whooshing so you can treat it as a quiet appliance.

Are Rinnai tankless water heaters noisy?

Most of the Rinnai tankless models do produce some sort of sound mostly due to the vibration of the unit.

Also, you can expect it to knock due to the accumulation of sediments at the bottom of the tank.

Even fluctuation in the water pressure and loose parts can add to the sound.

Also, obstruction in the free flow of water within the Rinnai tankless unit can contribute to unwanted irritating noise.

By following the methods that we’ve discussed earlier in this post, you would be able to deal effectively with any sort of noise coming out of your Rinnai tankless unit.

Why does my tankless water heater moan?

The majority of tankless water heater models moan because of sediments buildup at the bottom of the tank.

Some other reasons responsible for your tankless unit moaning includes fluctuation in water pressure, obstruction in water flow, loose parts, etc.

Why is my hot water heater making a high-pitched noise?

Mostly, high-pitched noise is caused due to the high incoming water pressure.

Definitely, it’s a unique problem that needs to be diagnosed quickly so that repairing can be done at the earliest in order to prevent any last-minute misadventure.

Excessive pressure isn’t good for your water heater as can lead to leaks and cracks.

In the worst-case scenario, the excessive pressure buildup can cause your water heater to burst so you need to be very careful and quick in dealing with a high-pitched noise.

In fact, water heaters are designed with a temperature/pressure relief safety valve.

The main function of such a valve is to open and release water whenever the temperature is too high or excessive pressure has buildup inside the unit.

Due to whatever reasons if such a valve fails to open and your water heater is over-pressurized then in that case, you need to address the situation in the best possible manner at the earliest.

How much noise does a tankless water heater make?

Well, in general, a tankless water heater takes less than 90 decibels so it will not impact your daily activities.

Due to underlying issues such as accumulation of sediments, loose parts, excessive pressure, etc, a tankless water heater can produce different types of noises with different decibels.

However, in most cases, the noises aren’t loud enough to create a problem for you.

What sounds are 90 decibels?

A normal conversation produces a noise of 60 dB.

You can think of a lawnmower as 90 dB.

Furthermore, a loud rock concert is around 120 dB.

To be honest, sounds above 85 dB can cause you harm depending upon how frequently and how long you’re exposed to them.

However, wearing an earmuff or earplug can protect you against high dB.

Why does my water heater sound like it’s screaming?

If your water heater is under pressure surely it will scream.

For safety reasons, almost every water heater comes with a pressure relief valve that opens and allows hot water to pass through when the pressure levels exceed a certain point.

If the pressure relief valve is working properly chances are very few that you’ll be aware of the fact that it got activated.

Unfortunately, problems happen when the valve doesn’t work properly.

A malfunctioning relief valve will lead to accumulation of pressure with nowhere to escape resulting in a sound similar to screaming.

Wrapping Up

First and foremost, I would like to thank you for being with us till the end.

Secondly, I would like to bring to your notice that I along with my core team have put loads and loads of effort into coming up with this idiosyncratic superlative piece of information.

And, in case, you liked our effort and want to appreciate us then please do share this post with like-minded people and the ones who are in search of it.

After all, sharing is caring, isn’t it?

So, do tankless water heaters make a lot of noise?


In fact, tankless water heaters are known to make noises that are less than 90 dB so they will not irritate your ears.

However, it is equally important to finding out the underlying cause in order to prevent any unprecedented event.

Trust me, we’ve tried to the best of our capabilities to cover almost everything that we could relate to the topic in order to help you in the best possible way that we could.

That’s all, as of now:)

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