Find the Cause of Your Noisy Boiler

Noisy Boiler

It’s normal to hear some noise from your boiler every now and then as it works to provide your home with heating and hot water, but what does it mean when you start hearing unusual noises? The likeliest answer is that there’s a fault with your system which needs to be resolved.

Whatever noise you’re hearing, you’ll find the possible cause with our comprehensive guide to boiler noises.

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Why is My Boiler Making Strange Noises?

There are a number of reasons why your boiler might have started making some odd noises and the cause can often be found by the type of noise being made. Find the noise that you’re hearing in the table below to identify the potential cause and get one step closer to a quieter boiler.

Type of Noise Possible Cause Require an Engineer?
Gurgling Air could be trapped in the system and result in your radiators not heating up properly. This can simply be resolved by bleeding your radiators. No
Humming There will be some degree of humming from a boiler as it operates but if it’s getting louder and much more noticeable then there might be a fault with the heating element of your system. Yes
Kettle boiling (whistling) If your boiler is making noise like a kettle then it’s due to an issue suitably named kettling. Kettling is normally caused by sludge or limescale building up on the heat exchanger and will require a powerflush to resolve. Yes
Vibrating In this case, the brackets might need tightening or some compartments might be open and need closing. If the boiler itself is shaking, then a gas engineer will need to secure the unit.
If neither of these is causing the issue then the circulating pump (that circulates water through the system) might be set too fast for your home.
Yes & No – You can tighten brackets yourself with a screwdriver and close any open compartments, but an engineer will need to secure the unit if the whole boiler is vibrating.
Tapping A component that’s been poorly fitted or come loose can cause a tapping sound and will need to be tightened. This could also be linked to a build up of sludge in the system and require a powerflush but depends where the tapping is coming from. Yes
Banging Your boiler making banging noises can also be caused by debris building up on the heat exchanger, requiring a powerflush to resolve. Yes
Dripping A dripping noise is a clear indication that there’s a leak somewhere within the system. This can often be caused by the pressure being too high or old boiler components wearing down. Yes

While not all of these require the assistance of a qualified heating engineer, if you’re in any doubt whatsoever you should hire one to carry out the necessary work.

What’s the Most Common Cause of a Noisy Boiler?

Kettling is the most likely cause of a noisy boiler, which comes as the result of sludge and limescale building up on the heat exchanger. As we mentioned earlier, one way to resolve this is with a powerflush, that clears out any debris in the system.

However, kettling is something that can be prevented by fitting a magnetic filter to your heating system as it collects any sludge, debris and limescale before it has chance to build up. Not only will this help to prevent your heating system from kettling but make it more efficient and extend its life too.

Is Your Boiler Leaking?

If you can hear a dripping noise coming from your boiler and the water pressure isn’t too high then the likelihood is that certain components of your boiler are wearing down. This is normally because the boiler has been heating your home for a number of years and might be close to heating its last radiator. At this point, you might want to consider a new boiler rather than just replacing the faulty component.

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More Causes of a Noisy Boiler

If the table above hasn’t got you any closer to a quieter boiler then there are still many possible causes to consider.

Thermostat set too high

Having your thermostat set too high can cause your boiler to make more noise than normal. This can be easily resolved by turning the thermostat down but if you end up having to choose between a warm home or a quiet one then you should contact a Gas Safe registered engineer.

Low water pressure

It’s worth checking that your boiler’s pressure hasn’t dropped too low by looking at the pressure gauge – it should be set to 1 bar. If the pressure is too low (or even too high) then you will need to repressurise your boiler.

Frozen condensate pipe

Condensate pipes are fitted to condensing boilers and send gases outdoors rather than into your home. As they’re located outside, they can freeze over and lead to your boiler making noise. To resolve the issue, the pipe needs to be thawed which you can do by pouring warm (not boiling) water on the pipe.

If you still can’t identify the cause of your noisy boiler then consult our guide to a noisy central heating system to get you closer to resolving the issue.

What to Do if You Can’t Find the Cause of the Noise?

If you still can’t locate the issue then take a look through some of the most common boiler problems as one of these could be having an impact on your unit.

In the case that you can’t find the cause of your noisy boiler then you should seek the expert advice of a qualified engineer. Get free quotes from up to 3 trusted engineers in your area by filling in a form today.

Get FREE boiler quotes

Get free quotes to supply and fit a new boiler now.