If your boiler has started to make a funny noise, one that sounds different from the occasional bang or rattle it might make, don’t ignore it and hope it goes away.
A strange noise from your boiler could mean there’s a fault that needs fixing.
Recognising the noise and what it could mean will help you or a professional fix the problem.
This guide will cover the typical noises your boiler makes when it’s having issues, what they actually sound like, possible causes, and how to fix them.
Boiler making a banging noise
If your boiler is making a loud, very frequent, banging noise that sounds like it’s coming from inside the boiler itself, that’s usually an indication of two main things
- Incorrect temperature: If the noise is very frequent, the thermostat on your boiler is likely set to the wrong temperature.
- Limescale build-up: If the temperature is correct, your heat exchanger may have limescale buildup that’s causing the banging noise.
How to resolve a banging noise
With this sort of noise, a Gas Safe engineer will need to diagnose the issue. While you can fix the issue with the thermostat yourself, if the temp is correct, they’ll need to check for any loose connections in the underfloor pipework.
If the problem is coming from your heat exchanger, you can remove the limescale yourself. Still, an engineer can perform a power flush (a chemical solution that travels through your system and pipes to remove all buildup).
Boiler making a gurgling noise.
If your boiler is making a gurgling noise, there are several things to check before the problem can be fully diagnosed.
The noise itself might sound like sloshing water, making it tricky to diagnose an issue based on that alone, as it could simply be the noise your boiler makes.
However, if you’ve noticed it is more frequent or if it sounds like air bubbles are being released, it could be an issue such as:
- Trapped air: A gurgling sound can be due to trapped air in your radiators.
- Water shortage: Lower water levels within the header tank
- Low water pressure: Check your gauge to ensure the system is properly pressurised.
How to resolve a gurgling noise
The best way to resolve the issue is to check the water pressure. The pressure should be between one and two bars.
If the pressure is too low, it’ll need topping up; if it’s too high, it will need draining.
Read more: Why does my boiler pressure keep dropping?
If your water pressure looks fine, trapped air could be the issue. For this, you will need to bleed your radiators. If you’re confident enough to attempt this yourself, it’s quite a simple process, but it can be messy and frustrating.
For a simple breakdown of the process, watch our tutorial below:
Keep reading: What temperature should my radiators be set to?
If the issue persists, then check the condensate pipe. It’s common for it to freeze up in cold weather, so if you’re experiencing this issue in winter, it could be the issue.
If you’ve done that and the gurgling persists (or if you’re experiencing this issue in the midst of summer), contact a Gas Safe engineer to take a look.
Boiler making a vibrating noise
A vibrating nose coming from your boiler could indicate a couple of different issues:
- Loose screws: Vibrations are frequently caused by components or pipework that haven’t been tightened correctly.
- Flue blockage: Something in the flue, such as dirt or debris, can cause rattling or vibration.
- Incorrect pump setting: If the pump speed is set too high for your system, it can cause the unit to vibrate.
How to resolve a vibrating noise
The most common reason is loose screws. Check the front and side panels for any movement that could cause vibration.
A simple tightening of these screws should hopefully suffice.
If screws aren’t loose, or you’ve tightened them and the issue is still there, it could be the flue that’s blocked.
For this, you’ll need a Gas Safe engineer to take a look. It’s illegal for someone who isn’t Gas Safe to attempt to resolve this issue.
Boiler making a humming noise
If you notice a steady humming sound coming from your unit, it typically points toward two potential faults that require your attention:
- Incorrect water pressure: Pressure outside the recommended range may cause a hum. You should verify whether the needle is too high or too low, following the same resolution steps outlined previously.
- Loose screws: Vibrations from components that aren’t secured tightly can cause this noise, among others.
How to resolve a humming noise
Tightening loose screws, checking your water pressure, and taking the necessary action if it’s too high or too low should resolve the humming noise.
If it persists, calling a Gas Safe engineer to inspect and diagnose the problem is the best course of action.
Boiler making a whistling noise
If your boiler is making a whistling noise, almost like the sound of an aeroplane taking off, there are a few different possibilities:
- Limescale build-up: If the whistling sounds more like kettling, this is likely due to limescale build-up on the heat exchanger, causing the water to overheat and steam.
- Leaky system: A leak in your system usually makes a whistling sound as water escapes.
- Faulty component: A failing pump, broken thermostat, or a blocked gas valve can cause overheating and high-pitched squeals.
How to resolve a whistling noise
A Gas Safe engineer is best placed to look at all of these issues.
While a build-up of limescale could technically be addressed by yourself – as mentioned above, an engineer can perform a power flush that will clear the build-up.
How to prevent noise and problems
Preventing potential problems before they creep up is the best way to eliminate noise and problems altogether.
So how do you keep on top of your boiler: Regular boiler servicing
Getting your boiler serviced annually is the best way to make sure your boiler doesn’t run into any issues.
As part of the service, a Gas Safe engineer will perform checks to ensure your boiler is at top efficiency.
Boiler cover is crucial if anything does pop up, as you’re not going to have to pay call-out fees and will receive further benefits like discounted parts that need to be replaced.
Between services and checks, keep an eye on your boiler’s pressure and any buildup of dirt or debris. Simple things like this go a long way in keeping the boiler in top condition.
Stay on top of your boiler; the efficiency will remain, and those noises shouldn’t appear.
