Why is my boiler making noises?

Why is my boiler making noises?

There are many reasons why your boiler may have started to make unusual noises and in his article, we will cover the various reasons and solutions to help you get rid of them.

If you read our blog content, then you will know that we take boiler care seriously. It is important to maintain your boiler both to keep your property and occupants safe and also to avoid costly repair or even a replacement.

Boilers can cause strange noises even when the system seems to be working perfectly, generating enough hot water for your home, but you should not ignore these noises as it may be a sign that you have a serious problem. Before we can fix the problem we first must identify the cause of the noise.

Where is the noise coming from?

Before we can fix the problem, we first must identify the cause and location of the noise. The big problem here is that noise can bounce through both the water and heating supply, so we first need to ask if the noise is coming from:

Boiler system
Central heating pipe

Without knowing the source of the noise, it will be impossible to treat and each one of the above units can have different causes and fixes for the troublesome noise. Once you have ruled out that the noise is not coming from the pipes or radiators we can look at the reasons why your boiler is making noise and start to find the solution.

Check for an error first!

All modern boilers now have a display that will provide information about the boiler, including pressure, etc. It will also display errors should there be a problem. If your boiler is making noise, then this is the first thing to check as the error display may just tell you exactly what the problem is. If you are like the majority of people (including me) the original boiler manual has probably been thrown away, then go online and find the manual regarding the error codes for your specific boiler using the model number and make of your boiler.

Error codes will not detect every problem, so there is a good chance that the root cause for the noises coming from your boiler is not being flagged up and no error code will be created therefore we will have to manually find the problem by completing these procedures:

Firstly ask yourself what noises are coming from the boiler if your boiler is making a:

buzzing noise from the boiler 

Unlike the noises that we will cover after this more problematic one, if you hear buzzing or even a whining noise coming from your boiler then it is a problem that will need to be fixed by a gas safe expert. This noise usually originates from a defective part such as the fan, bearings, or burner. If this is the problem then your boiler is not safe and the problem should be fixed immediately, to avoid a costly breakdown and to maintain a safe property. 

The boiler is ‘swooshing’ or vibrating

If your boiler is making a loud swooshing noise or even vibrating then you may start to get worried and that is understandable!! But unlike the buzzing noise above caused by a faulty internal part this vibrating or swooshing noise is an easier fix. 

Firstly check your boilers air filter

The blockage of an air filter is the most common reason for boiler issues that we see. On all modern boilers, the air filter is designed to be easily maintained and cleaned and you can do it yourself by removing it and cleaning any build-up of debris using a brush or even a vacuum cleaner. 


Check the flue

Another very common cause of this noise is a blockage of the air intake from the external flue. To check that your flue is clear, put your hand over the external fitting and you should be able to see if there is air running through it. If you can’t detect this airflow then this means that your air intake passage is blocked by debris and this should be cleared immediately. A blocked flue can be dangerous as fumes from the boiler are unable to escape and may release back into the home resulting in a buildup of carbon Monoxide, we have written a previous post on this subject which you can read here. 

A gurgling noise from the boiler

The problem here is that it is not unusual for a boiler to make this type of noise therefore there may be no problem to detect. What you need to ask yourself is has the noise become louder recently or has it started to make this noise more often? if this is the case then you may well have an issue. If you feel comfortable diagnosing the problem yourself then these are the steps that we would recommend if you don’t feel confident you can give our team a call or contact another gas-safe engineer to diagnose the problem

Bleed the system

Usually, these noises are being caused by an issue outside of the boiler itself and can be fixed by bleeding the system. this is something that you can carry out yourself by following a few simple steps In most cases, gurgling noises that may appear to originate in the boiler are caused by air elsewhere in the system.

The first thing you should do is bleed the radiators, Craig from Big Brother will show you how in his YouTube video below.


Thanks Craig! Once you have bled all of the radiators in your home you should check the water pressure and ensure that it is the optimal level of between 1-2 bars. 

Next check the circulation pump

After bleeding the radiators and making sure that the water pressure is between 1.2 bar then the next step and a common cause of the gurgling noise is the circulation pump. Sometimes the pump will be running too fast and this will cause noise, on some boilers you will have an option to reduce the speed at which the circulation pump runs, if not you should contact a gas-safe engineer to come and do it for you. 

As always if you do not feel comfortable taking any of the above work on yourself you can contact our gas safe team via our contact page here and we will send a qualified engineer to assess and fix the problem.

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