As with so many other appliances, an unusual boiler noise is typically a sign that something might be wrong and that a boiler repair call might be on the horizon sooner rather than later.
Whilst a boiler actively working to boil water or heat radiators is not completely silent, the hums or slight rushing sounds are typically consistent and can easily be tuned out whilst you are in the kitchen or bathroom where the boiler is based.
No noise at all can sometimes be a concern, but generally, if you are hearing no noise and there is a problem, the fact that you also are not receiving hot water or there is an error message on your boiler is a clearer indicator of a problem than the noise itself.
However, a strange, unusual or inconsistent set of noises emerging from your boiler when it is on might not merely be annoying or unpleasant, it could be a sign that you need to get your boiler fixed sooner rather than later, with the summer being ideal to get any repairs done before the temperatures drop again.
Here are some of the most uncommon boiler sounds and what they could mean.
Whistling And Hissing Like a Kettle
One of the most common strange boiler noises is also one of the loudest and most obvious signs of a potential issue when a loud, high-pitched whistle or hissing noise.
This is usually a sign of kettling, where due to limescale build-up, a faulty thermostat or a leaking boiler, the water is not circulating quickly enough and causing the water in the system to be overheated, leading to a whistling noise.
A Gas Safe engineer can provide certainty about the exact issue, but it can be a sign of a serious problem.
Buzzing
A buzzing noise is often a sign of an electrical component malfunction, which whilst it could be one of a number of parts from the pump to individual switches, is not a good situation given the relationship between electricity and water.
This usually means that you need an emergency callout, even if the boiler appears to be functioning normally aside from the noise. It is unlikely to remain that way for very long if you do not.
Loud Whooshes
This is usually a sign of trapped air in the system, which tends to be more common in combi boilers.
This can sometimes be merely annoying, but it is nevertheless important to get in touch with an engineer if you are a long time away from your annual inspection.
By contrast, gurgling and bubbling sounds are often caused by trapped air in your radiator, which can be fixed by bleeding them if you feel comfortable doing so yourself.
Knocks And Banging Noises
Knocking, clicking and banging noises are typically a sign of an issue with the boiler’s ignition, which can only be fixed by an engineer with Gas Safe certification.
Sometimes it can be caused by limescale build-up as well, similar to the knocking noises heard in a kettle, a faulty thermostat or one that has simply been set incorrectly.
