Home Improvement

Why Is My Central Heating System Noisy?

If your central heating system is making strange noises, you shouldn’t ignore it. The causes can often be something that is relatively easy to fix, but in worse case scenarios, can lead to problems that can result in bills amounting to thousands of pounds.

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The metal expands as it heats up and contracts as it cools down. Metal pipework is often susceptible to this as the temperature in your house fluctuates. Depending on where your pipework is situated, this may cause creaks and groans as they expand or contract. 

This blog post is for all of you who wish to:

  • Maintain their heating system properly;
  • Save money on heavy maintenance in the future.

Reason #1. Noisy boiler

A noisy boiler can often mean limescale has built up. The noise, known as kettling (because it sounds like a kettle that is boiling), is usually caused by hard-water build-up inside the boiler’s heat exchanger.

Chemical descalers can be added to the F&E tank, which will pump through your heating system and remove the excess limescale build-up. Following that, flush the system a couple of times with clean water. We also suggest adding some inhibitors to the system to help prevent corrosion and sludge build-up. You can have all that covered if you opt-in for our boiler and heat system cover which is inclusive of free annual boiler service

A noisy boiler could also indicate low water flow. Modern gas boilers call for a specific flow rate, so make sure it matches the requirements.

The air in your central heating system can also cause your boiler to make strange noises. This can sometimes be caused by incorrect installation, so it’s important to seek expert advice to make sure that components such as the open safety vent pipework are installed correctly.

Reason #2. Banging pipes

Banging pipes can be a result of overheating. If your pipes are making thudding sounds, the first thing to do would be to check your boiler’s thermostat. First, turn the boiler off and let it cool down. If the weather is cold and you need your heating back on soon, leave the pump running. This will help it cool off faster.

Once cool, switch on the boiler again and turn up the thermostat. You should hear it click. If you don’t, you should call us and we will send a boiler engineer to perform a thorough diagnosis of what the problem is.

Banging pipework can also be caused simply because the pipes are not secured properly. Copper pipes need securing from time to time to prevent rattling. If this doesn’t help, you might want to consider replacing your copper pipes with a more flexible plastic alternative. Vibrating pipes can also mean that they’re too narrow to handle the water flow. In such circumstances, replacing them with wider pipes would solve the issue.

Another reason for noisy pipes could be air getting into the system. This can cause your central heating system to corrode, resulting in a slight air or gas build-up. As it moves through the pipework, air can emit a water-like sound. The first step in this case would be to bleed the radiators to release it from the pipes.

If the noise persists, it’s time to call in the experts as it could be a symptom of a more serious fault that could damage your entire central heating system if left unattended.

Reason #3. Pump speed

If you hear annoying humming, it’s very probable that your pump is the culprit. In most cases, this means your vibrating unit needs securing. Brackets can be installed to reduce pump movement.

Alternatively, the pump speed might be too high. Try turning it down and seeing if this fixes the noise. If reducing the speed causes the radiators to heat up too slowly, give us a call. A central heating expert can visit your property and diagnose the problem. Moving the pump might be the best way to prevent any further issues.

If you can hear your pump running for too long after you have switched the boiler off, then there may be an issue with its pump overrun function. You can ask the expert to take a look at this, as well.

Need a professional to take a look at your heating system?

Get in touch with Fantastic Services now!

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  • If you address the cause of the noise of your central heating system, you’ll save a lot of money on heavy maintenance in the future;
  • The most common causes of central heating system noise come either from the boiler, the pipes, or the speed of the pump.

As a homeowner, you should know how to ensure the health and longevity of your central heating system. If you find a serious problem which you can’t fix or don’t know the cause of, you could always contact the professional handymen at Fantastic Services to help you out.


Is your central heating system noisy? Did you do anything about it? Comment below and tell us what happened!

Image source: shutterstock / ronstik

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