How to Soundproof a Boiler Cupboard (5 Effective Ways)

In this blog post, we will talk about “how to soundproof a boiler cupboard”, the different types of noises a boiler cupboard makes, and why it makes them. We will also discuss the best materials for soundproofing a boiler and 5 effective ways to do so. 

How to Soundproof a Boiler Cupboard?

Following are some effective ways to soundproof a boiler;

  • Hang Soundproof Curtains
  • Install Acoustic Panels
  • Use Fiberglass
  • Hang Acoustic Blankets
  • Lay Carpet Tiles

The Right Way to Soundproof a Boiler

You can easily soundproof a boiler if you have the right material and know the right way. Soundproofing a boiler can get tricky if you aren’t sure what materials to use and how to use them. 

Using soundproofing materials designed to block airborne noise would be useless as boilers make impact noise.

The noise that comes from a boiler is a vibrational noise of low-frequency and only a few specialized materials can help you eliminate this noise.  

Common Boiler Cupboard Noise Problems

It is not unusual for a boiler cupboard to make some noise as it has many vibrating parts. Let alone, the pump that mechanically pushes the water upwards to the heating system is a lot noisy.

Many of us ignore the usual boiler cupboard sounds to a point it gets unnoticeable. However, that’s not the best way to go about it particularly when you have the materials that can easily eliminate the boilers’ noise.   

To effectively soundproof a boiler, you first need to know about the sounds a boiler makes and why it makes them. Sometimes the problem is simple and the boiler display screen itself tells you where the problem lies.  

However, that’s not always the case, and most of the time you have to identify the noise problem and find an appropriate solution. In general, the boiler tends to make clicking, banging, humming, whistling, and vibrating noises.  

Clicking Noise  – Ignition Problem or Poor Gas Supply

An ignition problem usually happens when your igniter has gone bad or your gas supply is inadequate. This can be easily identified if you hear a series of tapping or clicking noises. If this is the problem, the boiler will simply stop working.

This is not a type of sound you can soundproof as it’s a problem that needs to be fixed. In truth, this is one of the more serious issues and requires the expertise of a plumber. 

A plumber will go to the root of this problem and either fix the ignitor or adjust the gas supply. This will surely solve the problem and get rid of the clicking noise.  

Hammering Noise – Low Water Pressure

You may also hear hammering or banging noises from your boiler. This is probably because of low water pressure. Loss of pressure doesn’t necessarily mean a pressure leak and sometimes boilers do their pressure dump.

On switching on the heating at times of low water pressure, the trapped air often strikes the walls of the pipe due to sudden pressure rise and creates a hammering noise. 

If your boiler pressure gauge is showing low pressure, a system leak is often the cause. A temporary solution to this problem is to increase the boiler’s flow rate to kip up the pressure. However, it’s best to call a plumber and get the leak fixed before it’s too late. 

Tapping Noise – Accumulation of Sludge

Sludge accumulation is not uncommon particularly with older boilers and in older homes. Over time, metallic water pipes tend to rust up and be damaged. 

This introduces sludge into the system that moves around the pipes, strikes the walls, and creates tapping noise. Besides this, it can even clog the boiler and cause a blockage in water flow. 

Quite often, all you need to do is flush the system to remove the sludge and fix the problem. You can also try using a cleaner to breakdown the solid particles so they can easily be flushed out from the system. 

Banging Noise – Airlock in the Boiler

Airlocks are common in any appliances that work with water. Trapped air in the pipe causes an airlock in the system and creates banging sounds. 

This banging noise usually comes from a newly-fitted boiler if the residual air wasn’t properly vacated on installation. Running hot water for long periods can also give a rise to this issue.  

The best thing to do is manually bleed the pump. You will find a screw in your boiler designed to bleed the pump. If you can’t find the screw, give a call to a professional who will come and solve this problem in a couple of minutes. 

Whistling Noise – Blocked Heat Exchanger

You may also hear kinds of gurgling or whistling noise from the boiler. If that’s the case, then a faulty heat exchanger is probably the culprit. 

A blocked heat exchanger creates these kinds of noise and it’s never a good sign. A heat exchanger is a crucial element of the system and uses thermal energy to heat the water. 

Most often, sludge accumulation is the cause of the blockage in the heat exchanger. 

Banging Noise – Limescale Accumulation

Besides sludge, many other minerals can also choke your boiler systems. Hard water contains many minerals such as limescale and mineral deposit is a serious problem in areas with hard water. 

These minerals stick to the pipes and flow into the boiler system and ultimately creates a blockage. This is often characterized by banging, tapping, or hissing sounds. 

The best way to resolve this problem is by flushing the boiler system using a limescale inhibitor. You can also install a limescale reducer to prevent the problem from aggravating the next time.  

However, this is not something that can be resolved in a day and often take years to completely clean up the system and remove mineral deposits. 

Humming Noise – The Pump 

The boiler pump does the major work in the boiler system. If you are noticing an increase in humming or vibrating noise recently, it probably means the pump is seized. 

The best way to identify this problem is to check the temperature of the pump. It shouldn’t be too hot and a normal working pump is only slightly warm. If the pump is too hot then it means the pump is seized.  

Quite often, the accumulation of sludge is also the cause behind this problem. However, resolving this is not easy and requires you to take the pump apart.

5 Ways to Soundproof a Boiler Cupboard

Now we know the different types of noises a boiler makes. Some can be resolved technically while others are unavoidable. So, if you desire to soundproof a boiler cupboard, your best bet is to use soundproofing. 

Some soundproofing materials work better than others but there are also a few things you need to take into consideration. Most importantly, you need to be certain that soundproofing material doesn’t lessen accessibility. 

To soundproof a boiler cupboard, you can either insulate the boiler or soundproof the surrounding. The goal is to minimize unwanted noises before it spreads into the house. 

You may even have to soundproof the floor, walls, or door to achieve the desired result. Don’t forget to leave empty spaces around the boiler. Usually, 10 cm below and 30 cm gap above the boiler is adequate. 

Hang Soundproof Curtains

One of the simplest, quickest, and easiest ways to soundproof a boiler cupboard is to hang soundproof curtains across the door. This can greatly help absorb the sound before it diffuses and spreads out. 

Using curtains with multiple layers and tightly-woven fabrics is the best as they greatly help curtail the sound. This is one of the cheapest ways to soundproof a boiler cupboard. 

Install Acoustic Panels

An acoustic panel is a great soundproofing alternative for a boiler cupboard as it is good at absorbing sounds. We know that boilers make impact sounds that can only be eliminated by sound-absorbing materials.

These panels are incredibly lightweight and flexible and can be hung on the door or used to line the cupboard.

Use Fiberglass

Fiberglass is a common insulation material used in many applications and places around the house. It is also used to fill the cavities in walls to absorb sounds.

To soundproof a boiler cupboard, you can use fiberglass around the edges to insulate the cupboard from the inside. 

It is important to check if you are buying the right fiberglass. Some are made for sound insulation while others are built to insulate heat. 

Hang Acoustic Blankets

Similar to soundproof curtains, an acoustic curtain is another cheap, effective, and simple material to soundproof a boiler cupboard. 

These blankets can be hung on doors or walls to absorb sounds in the same way a curtain does. Acoustic blankets made from polyester and fiberglass are popularly used for sound insulation.

Lay Carpet Tiles

Wooden floorboards are common in boiler cupboards as they are durable, strong, and good heat insulators. However, they are not good sound insulators and reverberate the sounds.

The best way to make them soundproof is to use soundproof carpet tiles. These tiles are designed to absorb sounds before they make their way to wooden floorboards. 

Carpet tiles are 10 times better sound insulators than wooden floorboards and adding them to your boiler cupboard can make a big difference. 

To enhance the soundproofing ability of carpet tiles, you can also add a soundproof underlay between the tiles and floorboards.


In this blog post, we talked about how to soundproof a boiler cupboard, the different types of noises a boiler cupboard makes, and why it makes them. We also discussed the best materials for soundproofing a boiler and 5 effective ways to do so. 

Frequently Asked Questions (FAQs): How to Soundproof a Boiler Cupboard?

How do you soundproof an airing cupboard?

  • Use Acoustic Panels
  • Install Carpet Tiles
  • Hang Soundproof Blankets or Curtains
  • Install a Fiberglass Barrier

How do you silence a noisy boiler?

  • Use Central Heating Inhibitor
  • Add a boiler filter
  • Use scale reducer 
  • Hire an engineer to do a power flush or hot flush
  • Check for leaks in the boiler
  • Check water flow rate and operating pressure
  • Check and remove airlocks in the heating pump

Should boiler be silent?

The boiler doesn’t necessarily have to be silent and a low hum noise is normal. But if your boiler is getting noisier and noisier with time then it’s certainly a cause of concern.  

Can you soundproof a boiler?

Yes, you can soundproof a boiler. Many soundproofing techniques can be used to cut down the boiler’s sound. Foam and cork are popular sound blockers used to soundproof a boiler. Fiberglass is another effective soundproofing material to minimize boiler noise.

Can a boiler explode?

In the past, boilers tend to get over-pressurized and ultimately explore. However, modern boilers are much safer and can withstand pressure spikes with ease. They can easily sustain pressure up to 20 PSI. When pressure exceeds this limit, they may fail or explode. 


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