How to stop noisy central heating pipes

It’s often said that you shouldn’t be able to hear a central heating system that’s running well and efficiently. Your heating should come on and off seamlessly with little to no noise. However, this isn’t always the case, and there may be times when you’re wondering if it’s normal for your pipes and radiators to sound like that. While it’s not usually something to worry about, a noisy boiler or central heating system could be a sign that something isn’t quite right and might keep you up in the early mornings when the system kicks in.

So, what is it that causes your pipes to make such a noise, and how can you stop it? Keep reading to find out.

What can cause water pipes to vibrate and make a noise?

There are a few reasons that could explain why the pipes in your home are making such a racket.

• Pipes rubbing on other surfaces

Newer houses tend to have piping that’s made from plastic, as it’s cheaper to install and more flexible. However, if you live in an older home (pre-90s), then your home is more likely to have copper pipes instead of plastic. As the water heats up and runs through the system, the copper also heats up and expands. As the pipes expand, they may be able to brush against other surfaces, like walls, joists, brackets and floorboards, causing a creaking, groaning or gurgling noise.

• Air in the system
  
  

If there is air running through the pipes and radiators as well as water, it can create a tapping or clicking noise. You may even be able to hear water gurgling. When there is air present, your radiators aren’t able to fully heat up, making them less efficient and your home a bit on the cooler side. This is why it’s a good idea to remove as much of this air as possible.

• Limescale in the system
  
  

Limescale is an annoying substance that can build up when you live in a hard-water area. Hard water contains lots of minerals, including calcium. When water dries up, this calcium is left behind and leaves a chalky residue known as limescale. It’s particularly prevalent in kettles, around taps and in a heating system. The trouble with limescale in your heating system is that you can’t see it.

If there is limescale in the system, you may experience the same problems as you would with air in the system. This can include radiators that are cold at the bottom and pipes that make a tapping noise. Limescale can also become stuck in your boiler, particularly within the heat exchanger, and can cause a whistling sound that’s known as ‘kettling’. 

Why do my pipes make a banging noise?

The most common cause of banging pipes is something known as ‘water hammering’. It may be more noticeable or only occur when you open a tap. The noise is caused by a sudden change in direction to the flow of water. When you open a tap, the water flows to it, and when you close the tap, the water should stop. Water hammering occurs when the flow of water is suddenly reversed. Over time, this action can damage the pipework and so the noise shouldn’t be ignored.

How to prevent noisy pipes

Now that you understand why your heating and hot water system and the pipes within it are so noisy, it’s time to stop the problem altogether so you can get a more peaceful night’s sleep.

Stop the pipes from moving

In most cases, noisy pipes are caused by movement as they expand and then knock against other surfaces. Therefore, one of the best ways to solve this problem is to check that all pipes are securely fastened and that they’re not touching anything else.

You will need access to your pipes to fix this problem, and this will likely involve taking flooring and floorboards up. Once the floor is up, you should check that all the brackets are tight and that no screws have come loose. Tighten any screws as required using a screwdriver. Use your hand to gently move the pipe around and see how much it gives. Ideally, it shouldn’t be able to move too much.

Then, you should check to see if any pipes are touching things they shouldn’t be, such as joists and other pipes. In these areas, apply felt between the pipe and the surface to prevent a banging or groaning noise when the heating comes on. The felt should fit snugly between the gap, and shouldn’t take you too long to fit.

If you’re unsure about undertaking this task yourself, you should contact a suitably qualified heating engineer.