Homeowners Professionals

How to soundproof a boiler cupboard

If your boiler is located in your bedroom, you may find that it wakes you up in the morning when it comes on and occasionally makes funny noises in the night too. Most noises are normal. This is because there are lots of things your boiler is doing all at once, such as heat the water and pump it around your heating system. However, these noises could be off-putting when you’re trying to watch television or go to sleep at night. We’ve come up with some ways you can reduce the noise your boiler makes as well as soundproofing solutions for your boiler cupboard.

How to reduce noise from your combi boiler

First, you may want to start looking into ways you can reduce the noise your  combi boiler  is making.

One of the main culprits of a noisy boiler is air. Air can get into the system and make the radiators and the boiler gurgle. You should bleed the system using a bleed key or screwdriver to address this problem. Open the valve and wait until water comes out, then close the valve again. You could also check the  pressure of the boiler, as this may be something else that’s causing your boiler to make funny noises.

If you’ve completed these tasks and your  boiler is still making a noise  that you don’t think is normal, you should call out a suitably qualified heating engineer to check the pump and the air intake/filter, and to look for any loose or broken parts.

If you’ve determined that there isn’t any air in the system and you’ve had an engineer out to check everything else is sound, you’ll want to look at soundproofing the cupboard that houses the boiler. But first, you need to determine what supplies are required.

What is the most soundproof material?

Some materials may do a better job at soundproofing than others, but you also need to consider what is safe and still allows easy access to the boiler. Cork and foam are renowned as particularly good sound blockers. There are other materials that may also be useful too, such as fibreglass. We’ve outlined some products and materials below that you may want to purchase to soundproof your cupboard.

Acoustic panels

Acoustic panels would be good for your boiler cupboard. They’re made up of a piece of fibreglass that’s sandwiched between two pieces of foam. They’re lightweight so they can be used to line cupboards or to hang on the backs of your doors.

Carpet tiles

Most boiler cupboards are made of wood and have bare floorboards at the base. The sound from the boiler will reverberate around the floorboards and the noise could even travel downstairs.

Your cupboard could be lined with special  soundproof carpet tiles  that help to absorb some of the sound. Carpet absorbs sound up to 10 times better than wood flooring, so lining your cupboard floor with carpet could make a big difference. To make your carpet flooring absorb even more sound, you should add a soundproof underlay beneath it.

Soundproof curtains

Soundproof curtains could be a good option to use when trying to reduce the noise coming from your boiler cupboard. As well as soundproofing inside the cupboard, you can tackle the outside too by hanging the curtains across the door. This is an inexpensive option that is easy to achieve.

The curtains should be heavy and tightly woven to prevent sound from travelling through the material. Most soundproof curtains will have multiple layers of fabric to create a barrier.


Fibreglass is a material that’s generally used for insulation. If you were to go into your loft, it’s likely that you’d find fibreglass laid on the floor to keep your home warm in winter and cool in the summer.

Fibreglass is made of glass that has been heated until it’s molten. When it’s molten, the glass is forced through very small holes to create glass filaments. These threads are woven into material, usually wool, to make it fire resistant.

The fibreglass will work better if it’s fitted into the space in a stud wall. However, this may not be an option for you, unless you plan to knock walls down. Instead the fibreglass can be installed around the edges of the boiler cupboard.

Be sure to look into the kind of fibreglass you’re buying for your boiler cupboard. Some fibreglass is for soundproofing but other kinds are for heat insulation.

Acoustic blankets

Acoustic blankets are similar to soundproof curtains. The blankets can be hung from walls or doors to help absorb any sound. They’re usually made of fibreglass or polyester and are lightweight for easy installation.

Soundproofing your cupboard

Once you’ve chosen your materials from the list above, you can begin to install them! You could use just one of the materials or a combination of a few to make your boiler so quiet you may forget it’s there.

Just consider that you may want to make the door soundproof, as well as the floor and walls, and this may require additional material.

You should also remember to leave enough space above and below the boiler in line with regulations. Double check your boiler installation guide to find out what gap is suitable. It’s usually a 30 cm gap above the boiler and 10 cm below.

Once you’ve deadened the sound of your boiler, you may need to check it regularly to ensure it’s all still working properly. For example, it may start to make a funny noise but you aren’t aware of it because you can no longer hear it. Every now and then, open the door to ensure there isn’t a gurgling or whooshing sound being emitted. If you do hear something unexpected, contact a Gas Safe registered engineer to take a look. 

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