Boiler Making Banging Noise – How to Fix?

Your boiler is a pretty important part of your home, and when it’s not working, it can be a real hassle. Unfortunately, boilers are prone to making weird noises sometimes. If you hear boiler making banging noise, it could be several different things. This can include leaking water in the system, too much air pressure, or the exhaust valve not opening correctly.

All of these issues are easy to diagnose and fix with just a few minutes of work. In this post, we will discuss how to diagnose and fix these common problems so that you can get back to enjoying hot water again!

The boiler is kettling

Kettling can occur when sludge or limescale builds up in the heat exchanger. The build-up can cause steam bubbles to form on the plate and then explode once they reach the surface. This makes a banging noise as they burst. If this is what has caused your boiler to start banging, then all you need to do is get it descaled by a professional engineer. They will use chemicals to remove all of the sludge and limescale that has built up in your system so that everything will run smoothly again.

Boiler making banging noises can be caused by:

  • An airlock in the system
  • Limescale build-up in the heat exchanger
  • System debris such as pieces of wire or scale or rust flakes
  • A faulty pump

Boiler Making Banging Noise – Common Causes & Fixes!

Here are some common causes of that banging noise from boiler and how to fix them:

1. First: Check the expansion vessel on your boiler. If it’s empty or needs refilling, this could be what is causing the ruckus. So check out the pressure gauge and make sure it’s at one bar of pressure—if it isn’t, simply top up your expansion vessel and see what happens!

2. The first thing we recommend is trying to bleed your radiators, which can be done by following this guide. When air collects in the central heating system, it can create a loud bang when the radiators heat up and the water has nowhere else to go but out of the air valve. This is a very common cause of banging sounds, but there are others too.

3. If you’ve bled your radiators and you’re still hearing that banging sound, then you could have a faulty pump or motorized valves that might need replacing. If one of these components isn’t working properly, then it could be causing water to move through the system faster than it should and cause banging noises as well as other problems with your boiler.

4. It’s also possible that the pipes are old and need to be replaced. In this case, the pipe banging is called ‘kettling’ and it is caused by vibrations in the pipes as hot water moves through them. The noise can be quite loud and it will often keep you awake at night if it happens in bedrooms or near living spaces.

How do I stop my boiler from banging?

Here are a few tips to help you troubleshoot the problem, and hopefully get some restful sleep tonight!

  • Check your pressure gauge
  • Make sure you have at least 1 bar of pressure
  • Turn on all hot water taps in your home to bleed any air out of the system
  • If that doesn’t work, turn off the power to your boiler and drain the system using the drain valve near the bottom of your boiler
  • Check your expansion tank—if it looks worn or old, consider replacing it with a new one
  • If you have questions about how to do any of these things, call a local plumber for assistance


Is the boiler banging noise a serious problem? It could be! There could be water trapped in your system, or air bubbles trapped in your radiators. The issue might arise from loose parts inside the boiler itself. If you hear banging, switch off the heating immediately and call an engineer.

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