Why is my boiler noisy? Causes and Fixes
Day-to-day we give little thought to the fact that our boilers are on and running. They should run quietly in the background whilst supplying our homes with hot water and warmth. But when your boiler starts making unexpected noises, it can be worrying.
An annual boiler service and regularly monitoring the pressure gauge are some of the simple ways you can maintain a healthy boiler system. Boilers don’t require lots of maintenance but by regularly inspecting your boiler in between services, it can make it easier to identify issues before they occur. If you do notice your boiler is making noises that are out of the ordinary, it is always best to try and identify the issue early to avoid costly repair bills in the future.
Identifying the sound of your noisy boiler
Typically your boiler should function without making excessive noise. When they are in use, faint whirring noises are common. For example, if the heating is on or a hot water tap is being used, it’s normal to hear a faint whirring sound as the water is heated and flows through the system. However, louder, unfamiliar noises can be a sign that there is an issue. Below we’ll help you identify what kind of noise your boiler is making and what could be causing it.
My boiler is making a gurgling noise
Gurgling noises from your boiler can signify that there is trapped air within the system. Whilst this is not a dangerous issue, over time it can put a strain on your boiler and affect its efficiency to heat your home.
Bleeding your radiators is a solution to fixing this problem and you are advised to do this annually. Over time, air can become trapped in the system which can prevent the heat from circulating properly, causing uneven heat distribution within your radiators. If you notice the tops of your radiators are cold when your heating is on, this indicates you need to bleed your radiators. Not only could this help improve the performance of your heating, but it could also save you money on your energy bills.
If bleeding your radiators does not solve the gurgling noises, we would recommend contacting your local Glow-worm installer to investigate.
My boiler is making a high pitched noise
If you notice your boiler is making a high pitched, whistling noise, your boiler could be experiencing boiler kettling. As the name suggests, it is often compared to the same noise a traditional stovetop kettle makes when the water reaches boiling point.
Boiler kettling can be due to several things. A build-up of debris and limescale is a common cause, particularly in hard water areas. If you notice a build-up of limescale in your kettle, the same could be happening in your boiler. This build-up causes the flow of water in your boiler and heat exchanger to be restricted, leading to a high-pitched whistling noise.
If you don’t live in an area with hard water, the noise could be caused by trapped air in the system. This is a relatively easy issue to fix and can be solved by bleeding your radiators.
My boiler is making a banging noise
If your boiler is making banging or knocking noises, this can also be down to kettling as explained above. Banging noises can also be caused by a faulty boiler pump or sensor. These issues can be harder to diagnose yourself and you should not attempt to open the boiler casing yourself.
Banging noises may also be coming from the pipework rather than the boiler itself. Sometimes the pipework might become loose and move as water circulates the system. You might be able to examine this yourself if the pipes are easily accessible. However, if you are unsure, it is always best to consult with a heating professional.
My boiler is making a loud vibrating noise
If your boiler is making a loud vibrating noise when it is in use, this could signify an issue with components within the boiler system such as a damaged pump or a blocked flue. You might also notice the pressure displayed on your boiler's pressure gauge is high. When your radiators are cold, your boiler pressure should be around 1.5 bars. If your heating is on and your radiators are warm, then anything between 1 and 2 is acceptable. If the pressure is outside of these ranges, the vibrating noises and pressure are likely linked.
If your external flue pipework is accessible, we would suggest inspecting this for any trapped leaves and debris and removing anything that appears to be blocking the pipe. However, if you suspect this noise is due to an issue within the boiler itself, you should contact your local Glow-worm installer who will be able to inspect this for you.
My boiler is making a loud humming noise
In most cases, if your boiler is making loud humming noises, it can indicate that there is an issue with the way water is entering and circulating the system. If water from the mains enters the boiler system at a high pressure or if heated water circulates the pipeworks too quickly, it can cause the valves and pipes to hum.
Persistent humming noises can also be down to components within the boiler system such as the fan. When your boiler is on, loose or faulty parts may move and vibrate within the system. In any case of a humming boiler, you should contact a professional installer to inspect the issue and avoid investigating yourself.
My boiler is making a noise like an aeroplane
If your boiler is making a noise similar to an aeroplane taking off or a hovering drone it is likely due to a faulty pump. A faulty pump can cause overheating within the system. As mentioned before, you should avoid trying to fix this issue yourself and instead contact your local Glow-worm installer to investigate the issue for you.
Is a noisy boiler dangerous?
Whilst a noisy boiler might be a nuisance, it is unlikely to cause any immediate harm or danger. Many modern boilers are designed to switch off if they have a critical fault. That being said, if you do notice unfamiliar noises coming from your boiler, these should not be ignored and left untreated as it is a sign your boiler is not working as efficiently as it should.
Contact your local Glow-worm installer
Our annual boiler service provides you with the best protection against unexpected faults and repairs as our engineers can spot issues before they arise. If you are experiencing a noisy boiler, contact your local Glow-worm installer who will be able to investigate and provide you with advice.