Boiler Combi Noisy Working ? If your boiler is making gurgling sounds or your pipes are unusually loud, it’s important that you identify the root of the problem as soon as possible. In this guide, we’ll explain how to diagnose a noisy boiler before it escalates into a more serious problem.
Why is the Boiler Working Noisy?
First things first, where’s it coming from?
This might sound like an obvious answer: “my boiler is making a noise, duh!”; however, whether it’s an old conventional tank or a modern but noisy combi boiler, all systems have various different parts and your problem can be isolated quicker if you pinpoint exactly what part the noise is coming from.
Check the error codes
Next is another, even simpler step: check for any error codes on your boiler. Most modern systems, combi boilers in particular, come with a digital display where you control all of your settings, timers etc. This is also where problems picked up by the boiler’s monitoring technology may appear, which again will help you more quickly ascertain what the problem might be.
Now, on to what noises might mean what.
Boiler making gurgling noise?
If this is this case and the sound is louder than the usual bubbling noises you tend to hear when the heating or hot water is on, then you may be suffering from low water pressure. A relatively straightforward step would be to bleed the system.
This noise is often caused by pockets of air trapped throughout the system, so bleeding the system can help release this, allowing you to start from scratch. Here’s how:
- Open all radiator valves and run the heating on full temperature for 10-15 minutes.
- Turn the circulation pump off and wait for the radiators to cool.
- Bleed the radiator closest to the boiler, making sure to lay down some absorbent sheets or towels, until water comes out.
- Repeat this for each radiator,
- Turn the boiler on and check the water pressure it should be between 1.5 and 2 bars.
Whilst bleeding your individual radiators may be the method most people are familiar with, many modern boilers come with a bleed screw/grommet on their pump, allowing you to similarly release trapped air from this point.
Boiler making vibrating noise?
If your boiler is making buzzing noises or seems to be vibrating, this can point towards a number of different issues of varying severity. This can range from something as simple as loose brackets – which is an easy DIY job to a problem with internal parts, such as worn pump bearings, faulty burners or the boiler fan itself.
If tightening brackets doesn’t get rid of the buzzing/vibrating noise, then it is likely that one of these problems is the cause. However, as with any serious boiler repair, this would require calling out a Gas Safe Registered engineer.
Boiler making banging noise?
If your boiler is making loud banging noises, there could be a problem with your thermostat or, equally, a build-up of limescale on your heat exchanger. If there is a build-up of debris, you’ll need to carry out a power flush. A power flush removes any blockages within your system and allows for hot water to move freely around your home.
Again, if the noise is significant, it’s best to be on the safe side and get in touch with a qualified professional.
Boiler making whistling noise?
Is your boiler making whistling noises? This is most likely a sign of limescale build up in your pipes and/or heat exchanger. The more clogged your pipes, the less water that is able to pass through, causing your heat exchanger to fill up with water and overheat, gradually releasing it as steam – hence it whistling like a kettle.
Whilst some build of limescale over time is expected, it can be worse if you live in ‘hard water’ areas of the UK. Regardless of whether this applies to you, not only will it affect your energy efficiency, but leaving the limescale to continue building up can seriously hurt your boiler, so be sure to get it fixed ASAP if you want to avoid further damage and prolong your boiler’s lifespan.
To remove the limestone, you need to run a hot water flush using a chemical solution known as central heating inhibitor: we will give you a brief summary of the process shortly and the solution is widely available should you choose to DIY.
Boiler making clicking/tapping sounds?
This is also one of the most common cases you’ll come across. If you hear your boiler clicking, the most likely cause is that the boiler is struggling to ignite. This can be for a number of reasons: no gas, low pressure, faulty valves or thermocouples, or even just a dirty pilot light.
While the lattermost is an easy job – just carefully remove any dirt and debris using a cloth and perhaps a wire brush – faulty valves or significant drops/increases in pressure can point towards a leak. Be sure to check for any staining around your boiler and if you can smell any gas.
Hopefully, this isn’t the case and even if you happen to have a faulty part, it’ll simply be a case of having a qualified professional come to carry out the repairs/replace the part.
FAQ
Boiler sounds like it’s on when it’s off
As mentioned, there are lots of natural sounds that you can expect to hear from a boiler and they shouldn’t cause you any trouble – a lot of the time, it’s simply water moving from area to another and echoes can be sent throughout the pipes.
Another common source of noise is what is known as the ‘pre-heat’ function. In combi boilers specifically, this is basically the sound of the heat exchanger firing up intermittently, making sure that it is ready to produce hot water when you need it.
However, if the noise is constant/every couple of minutes, this could be a sign of ‘short cycling’. This is when your thermostat detects the heat exchanger is cooling when your home has already achieved the desired temperature. This means that it is constantly trying to heat up that small amount of water, not only overworking your boiler but likely increasing your bills. This may require you to repair/replace your heat exchanger.
Boiler making humming noise when heating on – is that normal?
In short, yes. Your boilers circulating pump is what sends hot water around your house and it is fairly typical for you to hear some humming when using the heating or running a shower etc.
However, if the humming is particularly loud, this could be a sign that your pump is running too fast. If setting it at a lower speed doesn’t remedy this, then similar to our point about vibrations, check for any loose parts/brackets and perhaps check your boiler pressure this should never be above 15 psi.