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Causes of Noisy Central Heating

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  • 29-09-2021
Causes of Noisy Central Heating

What causes a noisy central heating system? We look at why your heating system is noisy and what to do if you have a noisy boiler.

Why is my central heating so noisy? 

In an ideal world, the only time you should notice your central heating system is when heating your home. Otherwise, it should disappear into the background. The best way to ensure this is to keep your heating system properly maintained. However, sometimes this isn't possible, or it has been too long between services, and your central heating starts to make itself known again.  

Having a noisy central heating system can be very annoying and distracting, and there are various possible reasons it has suddenly decided to speak up. This article will take you through these possibilities, explaining why your central heating is making those banging, knocking or humming sounds and what you can do to fix it.  

Noisy pipes, pipework or radiators

One reason your pipework or radiators may be making groaning, creaking or gurgling noises is that they naturally expand and contract as they heat up or cool down. 

As they expand, your central heating pipes will rub and scratch against other things, such as walls or floors, creating noises. 

One way to solve this issue is to check your pipework is secure and cannot move too much when it expands.  

What Causes A Noisy Central Heating System?

Other noises could have different causes. For example, if you notice a clicking or tapping noise in your central heating system, this could be due to having trapped air in the system. This is easily solved by bleeding your radiators. 

All you need to do is open the bleed valve on your radiators and allow the air to escape. Aside from noises, another sign that you may have air in your central heating system is that your radiators are not heating up properly. 

Noisy Pipes, Pipework Or Radiators

Louder, banging pipes are obviously more noticeable and are more common for those with copper piping in their central heating. 

This is a sign that your thermostat is set too high, causing your copper pipes to overheat. 

Again, the simple solution is to turn your heating down and allowing your pipes to cool.  

Another cause of loud or strange noises could be a build-up of limescale or sludge. This is a particular issue in the south of England, where hard water can build up in your central heating system. 

Professional plumbing services can flush out the system with specials cleaning solutions. Of course, you could try this yourself, but it is best left to the professionals if you are unsure of what you are doing.  

A final example of a cause for noisy pipes is water hammering. This is caused by the flow of hot water through your system suddenly reversing. Hammering occurs mostly when taps are turned off. 

It can be potentially dangerous, as excessive water hammering can damage your pipework. Again, it is best to contact a professional plumbing service to diagnose the problem.

Humming Noises 

Humming noises have also been known to occur with central heating systems and are almost always caused by the system's pump. 

You may also notice that there is a vibration in the system, which is also the work of the pump. The initial step is to ensure that the pump is secure and cannot move around while operating.  

Humming Noises in the heating system

Aside from being insecure, your pump could be vibrating because it is running at too high a speed. Unless you are familiar with your central heating pump, you should consult a professional plumber. 

Ultimately, if there is nothing else wrong with the pump, you can reduce its speed to solve the humming problem.

However, while reducing its speed will keep the pump quiet, it will also reduce the speed at which your central heating system can warm your home. 

Reducing this speed is not always the best solution, and professional plumbers can offer alternatives to keep your central heating running quietly and efficiently.

Banging Or Metallic Noises In The Boiler

Banging or metallic noises in the boiler 

Another possible source of noise could be your boiler. Unlike your pipework, where noises are easily solvable, if you notice your boiler making any strange or worrying sounds, this is a more serious issue. 

Therefore, if you notice any new or unusual noises coming from your boiler, you should immediately contact a professional boiler service as soon as possible.  

The most common noise that boilers make when in trouble is known as "kettling" and essentially sounds like a kettle boiling. 

The cause for this is limescale build-up, which can build up inside your boiler and restrict the water flow through your central heating system. This blocked water is then turned to steam by the boiler, hence the kettling sound.

While this can be a serious issue, it does not mean that you have to replace your boiler completely. Simply flushing and cleaning the system will fix it. However, you should always arrange for a Gas Safe registered engineer to carry out the work. It is dangerous for you to attempt it yourself, and many boilers services provide free quotes before they come to maintain your boiler.

Dripping noises 

A dripping noise coming from your boiler or pipework is a sure sign of a leak and is worth investigating. 

Along with the noise, look for signs of staining on walls or floors around your boiler and pipes to identify the source of the leak. 

Dripping Noises in your heating

If you do find evidence of a leak, it is better to have it fixed straight away. If you notice anything strange in general with your boiler or central heating system, it is best to contact a professional plumber or boiler engineer to have it checked. 

Spotting and repairing small problems now can save you money in the future, given that costs can rise dramatically when plumbing issues grow worse.

Are Your Pipes Banging?

Are your pipes banging? 

A banging noise coming from your pipes is a sure sign of water hammering. There are several reasons why this could be happening, including overheating or having air in your central heating system. The first thing to do when you notice this is to check your thermostat. If it is too high, try turning it down or switching off your boiler for a while. This will give the system time to cool down.  

Once you have done this, switch the heating back on and turn your thermostat up. After you have done this, you should hear a click. If you do not, you should contact a professional boiler engineer and have them look at your heating system.  

Another common cause of banging noises coming from your heating system's pipework is insecure pipes underneath your floorboards. This is very common with copper pipes, given they tend to expand and rattle when hot. 

A quick fix is to wrap felt tightly around the pipes to stop them from moving too much. Applying the felt wherever the pipes or their joists touch one another or the floorboards is the best way to go.

If you have already done this or had a heating engineer come and fix your noisy pipework, but the problem persists, it could be time to invest in some plastic piping. 

Plastic is far more flexible than copper and will not expand or move around when heated up. This is just one way of reducing the noise produced by your plumbing and pipework.

Do you have a noisy boiler? 

Boilers tend to make at least some noise while in operation, which is quite normal. However, if the noises do not sound right or are very loud, it may be time to call the professionals. The "kettling" mentioned above is a classic example of strange sounds that denote a significant issue with your boiler.  

Do You Have A Noisy Boiler?

Of course, you should never attempt to fix your boiler on your own. This is far too dangerous and should be left to those with the necessary training and expertise to perform boiler repairs. Essentially this means professional Gas Safe registered boiler engineers. If you have any concerns about your boiler, contact your local professional engineers to assess the issue and make the necessary repairs.


Do you have a noisy central heating system? We offer services to both domestic and commercial customers throughout Uppingham, Oakham, Stamford and Rutland. Our charges are highly competitive and realistic. If you are experiencing noisy central heating - Please contact us.