My Noisy Boiler

Picture of a noisy boiler | Letsgo TNT Gas & Heating Engineers

A Guide On How To Fix Your Noisy Boiler

Are you wondering why you have a noisy boiler but don’t know why it’s making these irritating noises?  A noisy boiler isn’t always a cause for concern, but there are certain noises to look out for, and each one comes with its own fix.

It’s not until our boiler gets that little bit older and starts to make strange noises that we begin to realise the importance of a properly working heating system.

Don’t be too alarmed because the problems causing the noisy boiler can be fixed quickly.  If your boiler is already quite old and starting to cause issues, it might be time to have it replaced with a much more efficient boiler that can save you money on your energy bills.


In this guide, we’ll take a look at what causes a noisy boiler:

Kettling noises

Vibrating noises

Banging noises

Gurgling noises

Humming noises

Whooshing noises

Buzzing or whining noises


Kettling noises


Another thing that can cause a noisy boiler is Kettling.  This can happen when the flow of water through the boiler slows down, causing it to be heated too quickly and rapidly reaches boiling point. Air then becomes trapped in the system and results in steam being generated, which causes a whistling sound.

This can be caused by circulating issues which means the water doesn’t flow around the system properly.  The main causes for kettling are either a faulty pump, limescale or poor water quality in the heating system.

Kettling can be a serious problem that should be looked at by a gas safe registered engineer.


Vibrating noises

Vibrating noises may well be the result of loose brackets or screws that only need tightened.  Something this simple can cause a noisy boiler but it could be fixed quite simple by yourself.  If your pump is set incorrectly, it could be faulty and shaking inside the boiler which is causing vibrations.  In this instance, you would need to call out a Gas Safe registered engineer to diagnose the issue.


Banging noises

Banging noises may cause a noisy boiler and this sound normally comes from a faulty boiler thermostat.  This means that limescale has built up inside the heat exchanger, which might need to be flushed out by a professional heating engineer.

Banging noises can also come from pipes under the floor that are not secured.  In this instance, you can get under the floor and check for unsecured pipes and fix it.  Alternatively, if you are not comfortable with this, you should call out a heating engineer.


noisy boiler


Gurgling noises

Yet another irritating cause of a noisy boiler is a gurgling noise is most commonly caused by trapped air in your radiators.  However, if it is cold outside, it could also mean a frozen condensate pipe.  Low water pressure could be another reason for this.

The first thing you should do is bleed the radiator.

Turn your heating off and give enough time to cool down, follow these steps:

  1. Get a radiator key.
  2.  Put a towel and jug at the bottom of the bleed valve.
  3. Slowly turn the radiator key anticlockwise.
  4. Let the air be removed from the valve.  You will hear a hissing sound.
  5. When the water is present through the bleed hole, close the valve.

Once this has been done, check your boiler pressure after bleeding the radiator as it might have dropped below the minimum requirement, usually 1 to 1.5 bar.  If it has dropped below the green zone, top up using the filling loop.

If it’s winter and cold outside, you should check for a blocked condensate pipe.  To fix this, apply heat to the external section of the pipe.  This can be done with warm water or a hairdryer.


Humming noises

Humming noises can be caused by the pump moving the water around the system too fast.  To fix this, you need to get a heating engineer to adjust the speed setting on the circulating pump.

If the noisy boiler continue after adjusting the circulating pump, you may have a problem with your boiler fan, which will need to be looked at by a professional heating engineer.

Whooshing noises

Whooshing noises are prevalent in combi boilers.  These noises are most likely coming from a blocked circulation pump.  You need to call out a gas safe registered engineer to confirm this is the case and he will either manage to unblock it or possibly replace the pump.


Buzzing or whining noises

This is not a noise that you will want to hear.  Typically, this noise comes from worn pump bearings.

If you can hear your boiler making a buzzing sound, you should listen to it.  This is your boiler telling you that it needs help.  Unfortunately, in this scenario, there is nothing you can do to fix it. You will need to call out a heating professional to replace the circulating pump.


noisy boiler


Rattling noises

The most common reason your noisy boiler is making rattling noises is having loose bolts in your boiler.  However, this strange  noise can mean other things.  Sometimes they come from blocked air in your radiator pipes. In this instance, you should try to bleed your radiator to see if the noise stops.

If all seems well, check for unclipped pipes or open valves.  If you are able to locate them and feel confident, fix them yourself.

If you are still unsure of the cause of the boiler noises, it is best to call a heating engineer.  You may have a faulty pump or valve that you are unable to fix yourself.


Extra Tips:

Your noisy boiler may show an error code, helping you diagnose the issue quickly and efficiently.  Some problems may be easy enough to fix yourself, whilst others will require the assistance of a Gas Safe Registered engineer.  Remember, not all issues will generate a boiler fault code so the above steps may still be necessary.


If you don’t have access to your boiler manual, you should be able to locate it online.

Here are some boiler manufacture fault codes:






Hopefully you have gleaned some valuable information from this blog and we would really appreciate some feedback.  You can share it with friends and family on your social media feed if you think it will help others.

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