How To Reduce Noise From Tankless Water Heater

Water storage tanks are now being replaced by tankless water heaters because they produce the same amount of hot water that you can get from a storage tank. This suit-case-size tankless water heater doesn’t store water in the tank. Instead, they use a heat exchanger to rapidly heat up the water as it passes through the unit. Being compact in size, these tankless water heaters save the floor space as they are mounted on the wall.

Regardless of being beneficial, these tankless water heaters at times can get too noisy. In such a case, you need to come up with a possible solution to solve this problem. To help our readers fix the noise issue we have written this handy guide about how to reduce noise from tankless water heater.

One main reason for being too noisy is that the vacuum of the water heater is pouring out water from the unit. Another reason could be a dirty flow sensor that controls the amount of gas transferred to the unit. If you are facing the same issue, then stick to this article as we will discuss some of the important ways that can help in reducing the noise from your tankless water heaters.

How to Reduce Noise from Tankless Water Heater?

In order to reduce the noise from tankless water heaters, firstly you need to clean up the whole system by using vinegar. Make sure that all the loose parts are tightened while inlet and outlet valves are completely open. The best part is that you can perform these methods on your own without calling a plumber.

Identify the Cause of Noise

To solve the problem in a better way, the first thing that you should do is to identify the cause of the noise. Reaching out to the sound location will help to eliminate the cause of the problem. Typically, tankless water heaters create a different type of noise if the parts are loose, water flow is blocked, vibration, or if the water pressure fluctuates, which helps in indicating the problem easily.

  • Blockage of Water flow: when water is blocked, the most common sound that is produced is screeching. If you hear this type of sound coming out of your tankless water heater, then it means that the water flow of your unit is blocked.
  • Loose Parts: if your tankless water heater is creating the rattling and humming noise, then the problem is with its parts. When the parts of the tankless water heaters are loose then a humming and rattling sound is produced that can be reduced by tightening up those loose parts.
  • Water Pressure Fluctuation: as the water pressure changes in the unit, the ticking sound produced indicates the problem of pressure in the unit.
  • Sediment Buildup: when sediment buildup is in your unit, then you typically hear hissing and cracking sounds from your system. Furthermore, in extreme cases, the popping sound is produced when sediments start to break due to excessive heat.
  • Vibration: when water pressure starts to change, then a ticking sound is produced which indicates the vibration or changing of water pressure.

Take Proper Corrective Actions

  • Treating Water blockage: After identifying the screeching noise created by water blockage, check that the water inlets and outlets are fully opened. If they are not in a fully open position, turn them in a counterclockwise direction. If the problem is not solved yet, then call the plumber for inspecting the temperature, water line, etc.
  • Treating Loose Parts: by identifying rattling and humming sounds produced by your tankless water heater, tighten up all the loose parts of the system to reduce the noise from your unit. It is very important to identify all the parts as treating them incorrectly can affect the system and can cause damage to the whole system.
  • Treating Water Pressure Fluctuation: as water pressure fluctuation produces a ticking sound, it can be treated by tightening any loose straps by holding down the pipes. Moreover, another way is to install a spacer between the pipes and the walls for reducing the noise from tankless water heaters up to a great extent.
  • Treating Sediment Buildup: hissing and cracking noise is produced when sediment buildup is in your unit. For treating this noise, you will need to clean up the whole system by using vinegar the removal of sediment buildup. In extreme cases, when sediment buildup occurs inside the heating element, then the heating element has to be removed and cleaned by using vinegar and a wire brush.
  • Treating Vibration: for treating the ticking noise produced by a tankless water heater, install a rubber foam or a mat between the system and the wall. Moreover, if the system is fixed in an enclosed case, then insulate the inner system by using audio insulation that is designed for automobiles.

Preventive Measures

By taking proper preventive measures, you can actually keep your tankless water heaters free from any issues. Do check the parts of the system periodically for proper functioning as they might get loose with the passage of time. Also, make sure that the inlets and outlets are opened fully to prevent blockage of water. Furthermore, for enhancing and maintaining the performance of the tankless water heater, clean up all the system once with vinegar that prevents sediment buildup.

Moreover, for regulating water pressure and preventing fluctuation, install the spacers between the pipe and walls before the noise becomes an issue. Frequently check the loose straps that are there inside the pipes connected to the heating system of the tankless water heater in order to solve the issue and prevent noise creation in your system.

How to SoundProof Your Water Heater?

Insulation of Water Heater

Most of the models already come with insulation that is fitted on the outer side of the tank. However, if your tankless water heater does not have any insulation then the best way to provide it is to wrap the heater with fiberglass insulation around the tank. As it provides thermal insulation, it can also muffle the sound too. Furthermore, using vinyl tape will provide better insulation as it is heat resistant.

Soundproof Your Room

When you soundproof the room in which the tankless water heater is kept will reduce the noise pollution to a great extent. However, the best possible solution is to build your own room for the heater by constructing the wooden frame around the tankless water heater. This ensures maximum airflow while providing enough space for soundproof material. One of the best soundproof materials is Rockwool which is made from mineral fibre and works best as both thermal and audio insulators.

Another best soundproofing material is mass-loaded vinyl which provides thermal insulation properties. Moreover, another best option is a vehicle sound deadening mat that is an effective option for soundproofing tankless water heaters. These mats also have an extra layer of foil that provides extra thermal insulation to your water heaters.

Soundproof Doors and Ceilings

If your tankless water heater is kept in the basement, then you should soundproof your ceilings and doors in order to reduce the noise pollution that is experienced in the house. Similarly, if you are keeping your tankless water heater in the cupboard, then soundproofing its walls and doors is a necessary option. For soundproofing, the ceilings and doors, use acoustic insulation foam whose function is to deaden airborne soundwaves.

Maintaining Water Heater

It is a very important step as it enhances the performance of the tankless water heater. Different types of noises that tankless water heaters produce are due to some of the potential issues in the system. But these potential issues can be avoided by regularly maintaining the water heater. For better maintenance, it is recommended that the system should be cleaned up with vinegar once or twice a year.

Flushing out the system will prevent sediment buildup, providing you with a chance to analyze your water heater’s health. Moreover, by regularly checking the pipes and loose components, you can catch the problem before it becomes too big to handle. If you are unable to detect the problem, then you should call a plumber to solve that issue.

Solutions to Other Tankless Water Heaters Problems

Blockage of Exhaust

When the exhaust of the unit is blocked, then the problem is there with the venting. In order to fix this problem, check the connections of the vent pipes whether they are connected accurately or not. Furthermore, make sure that there should not be any blockage in the exterior vents. If any blockage is found in the exterior vent, then remove it by making sure that nothing can again block the vent pipes.

Ignition Failure

When these tankless heaters fail to ignite, make sure that the water and gas valves are fully opened. If they are not opened properly, then rotate the tap in a counter-clockwise direction. If your tankless water heaters use natural gas, then make sure that it is efficiently provided to the heater. Likewise, if the heater uses propane, make sure that your tankless water heater is not left empty. If these steps fail to solve the issue, then the problem is with the tank’s ignition pack which is then fixed by a plumber.


A tankless water heater operates best at the temperature of 120°F. If your water heater is facing an issue of overheating, it probably means that multiple hot water sources are used simultaneously. And if the water heater shuts down after overheating, then, in this case, check its temperature. If the problem is still unsolved and overheating continues, then you must call a plumber to solve this issue as soon as possible.

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Why is my tankless water heater so loud?

The main reason tankless water heaters are so loud is their dirty flow sensors that function to transfer a limited amount of gas to the unit. Noise can also be produced by blockage of valves, fluctuation in water pressure, blockage in ventilation, etc.

How can I soundproof my water heater?

You can easily soundproof your tankless water heater by using a fiberglass insulation blanket that helps in reducing noise pollution. Although there are many other types of insulating materials available in the market, the best one is fiberglass which has the best soundproofing properties.

What maintenance is required on a tankless water heater?

By regularly maintaining your water heater, there are fewer chances of occurrence of potential issues. Flushing out the system can reduce the sediment build-up whereas cleaning the air filters can prevent blockage in ventilation. Furthermore, check out whether the components are tightened up properly or not.

What is the normal sound for tankless water heaters?

Hissing and cracking sounds are the most common ones that are produced by electric tankless water heaters. If your system occasionally produces these types of noise then it’s not a big deal.

Are tankless water heaters quieter?

Homes without propane tanks and gas lines can enjoy the benefits of tankless water electric heaters that are quieter and heat up water by using thick copper rods. They are also smaller than the gas tankless water heaters.


Tankless water heaters are the most beneficial investment for your homes in order to improve energy efficiency, streamline your budget and provide an endless supply of hot water. These tankless water heaters are highly durable and can last up to 20 years with regular maintenance and care. If these heaters are not maintained properly, many potential issues can arise in the form of noise. Different issues have different noises and by indicating specific noise produced by the water heater, you can easily reduce the noise caused by a tankless water heater.

With years of experience under his belt, Adam decided to put his water heater knowledge to work. By providing high-quality content and expert guides, Adam hopes to help anyone looking for expert water heater advice.