Below are 6 reasons why your boiler might be making a noise

Let us congratulate you on taking the first steps to figuring out why you can hear a strange noise coming from your boiler.

So … why is your boiler making a noise …?

The truth is everyone’s central heating system probably makes a ‘strange noise’ at some point. When your boiler, radiators or pipes start making strange sounds, it can often be quite worrying.

Don’t worry

However do not fear, many odd noises are simple problems with quick fixes and this is why we’ve put this simple guide together to help you tell which is which.

Remember, if you are ever unsure or worried take the necessary steps and by all means call one of our registered  gas engineers at Heywood Heating.



Top 6 noises your boiler is making
Below are the top 6 noises you’re probably hearing from your boiler

The most common and usually the simplest to solve central heating noise is referred to as ‘kettling’. That’s because it sounds much like a kettle boiling. The simple diagram below illustrates how the build up of sludge is restricting the airflow in the radiator.

Kettling is quite a common issue and is usually caused by a buildup of sludge or limescale in your heating system. If the buildup is severe, you may require a powerflushing service to remove the sludge and get your central system back in full working order. You can find more information by calling us for a free chat.



A dripping noise coming from your boiler may be caused by a leak within your system. If this is the case, never attempt to fix the issue yourself. Call a professional engineer to properly diagnose and fix the problem.

Having a leak within your boiler is often the result of your pressure being too high, causing the leak to occur. It can also be the result of the wearing down of your boiler components, particularly if your boiler is old. In some cases, it may even be cost effective to replace your boiler with a more efficient new one. 


Hearing a gurgling noise coming from your radiators? This is usually caused by an air buildup in your radiators and should have a very simple fix. You may also find that part of your radiator is not being heated fully.

Bleeding your radiators will solve a gurgling problem in most cases. This is a very simple process to carry out yourself, but if you’d prefer to give us a call we can solve the problem.

It may be something more serious that requires fixing by an expert. Either way it’s best to give us a call to let one of our professional heating engineer to diagnose the cause of the problem.

A tapping noise coming from your central heating system could be caused by a part being fitted incorrectly. If you’ve recently had a new part fitted or changed, this is the most likely cause of your tapping noise. Call in an engineer to have the part fitted correctly.

Tapping may also be caused by a buildup of limescale, particularly if you live in a hard water area. If this is the case, you may require a powerflushing service to correct the fault.


As water passes through your pipes, they expand and contract due to heat. If the pipes in your central heating system have not been fitted correctly, this could cause a banging noise to occur. This noise may be particularly prominent if your pipes are close to the floorboards.

You may need to call out an engineer to refit the pipes correctly and solve that annoying banging noise problem.


Your boiler will probably produce some noise during normal operation. However, if there is a noticeably louder humming sound coming from your boiler, this could be caused by a problem with the heating elements in your system.

This is not really a problem you can diagnose yourself, and you shouldn’t attempt to tamper with your boiler to find the root of the issue. Call out an engineer to safely fix the problem and get your boiler back in full working order.


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.

In Summary…

There are many different noises that your central heating system can make, and while some of them can seem worrying at first, most will be easily fixed. If you are at all unsure about any noise your heating system is making, the safest thing to do is call our friendly boiler repairs team on 020 8575 2221 or contact us here.