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Why Is My Central Heating Noisy?

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Is your central heating system making strange noises? If your central heating system is making strange noises, it can be quite unsettling and shouldn’t be ignored. The causes of a noisy central heating system can usually be fixed quite easily. However, in some worse case situations, it can result in expensive repair bills. In this article, we help you answer, ‘why is my central heating noisy?’.

So, Why Is My Central Heating Noisy?

Your central heating system is made of metal which expands as it heats up and contracts as it cools down. Normally the creaking sound your central heating system makes is just the sound of the pipes changing with the temperature. On the other hand, some noises are caused by different issues and shouldn’t be ignored as they may be lead to more serious problems.

Typical Noises Your Central Heating Makes

When you switch your central heating system on it can make different noises depending on the pipework’s age and condition. Here are typical noises your central heating system might make:

  • Banging 
  • Buzzing 
  • Clanking
  • Clicking
  • Clunking
  • Gurgling
  • Humming
  • Kettling
  • Knocking
  • Vibrating

5 Reasons Why Your Central Heating is Noisy

Here we explain 5 reasons why your central heating is noisy:

  1. Natural Start-up Process
  2. Build-up of limescale and sludge within the system
  3. Loose pipes
  4. Airlocks in pipework, radiators or pump
  5. Water hammering

One reason why your central heating system is noisy may be due to the natural start-up process of the system. If you hear tapping, knocking or banging from the floorboards and walls when you switch your central heating system on then the noise is likely to be part of the natural start-up process. During the start-up process the pipes, radiators and every other part of the heating system will expand as they heat up which causes these tapping, knocking or banging noises. You can also expect to hear similar noises when the heating is switched off as the pipes will be contracting. If you find there is an area within your house where the noise is mainly coming from then one of our qualified heating engineers will be able to lift up the floorboard and re-route the pipework to make sure it’s got adequate space to expand without touching the floorboards.

Another reason why your central heating is noisy could be due to the build-up of limescale and sludge within your system. Typically, in hard water areas limescale builds up and also sludge builds up within most systems. If you have a build-up of limescale and sludge within the system you can expect to hear tapping and clicking noises. To fix this issue, one of our qualified heating engineers will flush your system to remove as much limescale and sludge as possible.

A third reason why your central heating system is noisy could be due to loose pipes. Pipes that are not secure could be causing banging, clunking, knocking and vibrating sounds. To solve the issue of nosy pipes, you will need to re-secure pipes onto their clips. However, if you find the pipes are already secure then you may need to reroute the pipes to stop the noises. One of our heating engineers will drain the system, cut out section of the pipework, fit new pipework and refill the system.

Another reason you have a noisy central heating system could be due to airlocks in the pipework, radiators or pump. If you hear banging, clunking or knocking noise then it is likely there is an airlock within the system. To remove an airlock you will need to bleed your radiators. If you haven’t bled a radiator before, read our helpful guide on how to bleed a radiator.

A fifth reason why your central heating system is noisy could be due to the use to water hammering when using taps. Loud knocking sound could be caused by water hammering. Water hammering is an instant surge in the energy circulating water in pipework. To stop water hammering you will need an engineer to fit a water hammer arrestor. When the surge is likely to create water hammering then the water hammer arrestor will absorb the excess energy acting as an overflow.

For more information on why my boiler is making loud noises read our article.

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