Why Your Worcester Boiler Is Making a Loud Vibrating Noise

worcester boiler vibrating noise

Last updated: April 27, 2022 at 7:59 am

Boilers aren’t cheap, and they are vital for almost every home because they provide hot water and central heating. So, it’s understandable that if your boiler starts making unusual sounds, it can be a real worry. Not only could you be looking at a costly repair, but there are safety concerns too.

So, let’s look at the main reasons your Worcester boiler might be making a vibrating noise.

5 Reasons for a Worcester Boiler Loud Vibrating Noise

1. Limescale Build-Up

If you live in a hard water area, your water supply will contain a higher concentration of minerals. These minerals can cause limescale build-up in any parts of your home regularly exposed to water, including showerheads, taps, kettles, washing machines and boilers. It shows as a hard white substance that can be very difficult to remove.

If limescale builds up in your boiler’s components, the heat will be distributed unevenly. As a result, it can cause steam bubbles that pop and cause a gurgling or vibrating sound.

If you suspect limescale is the problem, you should call in a professional who can perform a powerflush. Flushing the system will remove a large amount of the scaling and hopefully stop the noise.

Once the flush is complete, you should consider adding a scale reducer to your plumbing. It will reduce the amount of limescale able to enter your system and stop future build-ups.

Related: 7 Noisy Boiler Noises and How to Fix Them

2. Faulty Heat Exchanger

boiler heat exchanger

Limescale build-up can also cause issues with your heat exchanger. If it is heavily caked, your heat exchanger will not work efficiently and could break down altogether. Even if you don’t live in a hard water area, the heat exchanger might be failing and causing the noise. Only a properly trained professional will be able to confirm if this is the case.

If your heat exchanger is at fault, you should carefully consider the age of your boiler. If it is relatively new and in warranty, replacing it is the best solution. However, if it is out of warranty, it’s best to weigh up the repair costs versus replacing the boiler for a newer, more efficient model. Repairing a heat exchanger can cost up to £500, at which point it’s only an extra £200 to replace the whole boiler. Newer boilers are more energy-efficient, quieter and the reduced running costs may earn a portion of the cost back over time.

3. Parts Of the Pump Have Seized

The most common cause of a loud vibrating noise in a Worcester boiler is when one of the parts in the pump seizes. Luckily, it’s easy to check if this is the case. Carefully put your hand on the pump to check its temperature. If it’s working correctly, it should be warm but not hot. So, if it feels hot, you’ve found your culprit.

If you need the boiler to keep working while waiting for a plumber to arrive, you can gently tap the pump to release the seized part. Long term, however, you’ll need to find the problem. The most likely causes are limescale build-up, as explained earlier, or a build-up of dirt and sludge in the system. A powerflush is recommended to clean out the system. If this does not stop the noise or cool the pump, you may need to replace the faulty part.

Also read: How to Soundproof a Boiler Cupboard (Kitchen or Hall)

4. Poor Installation

If your boiler is new, then whoever installed the boiler may not have securely fastened all the components. For example, if the boiler is not securely attached to the wall, the boiler or the pipework may be moving too much and causing a vibrating sound. Gently press the boiler on all sides, look for movement, and then check your pipes too.

If they move too much, you can see if you can fix the problem yourself. Assuming the pipes are moving, you can add additional brackets or fixings. If the boiler is the issue, try tightening the screws that hold the boiler to the wall. If you think the problem may be caused by the boiler vibrating along the walls you could add a piece of foam or mass-loaded vinyl behind it to act as a barrier.

Once you’ve tightened everything up, make sure any compartments on the boiler are closed and see if the boiler is now running quietly.

5. Pressure Problems

boiler pressure

If the pressure is either too high or too low, it can cause vibrating or a loud humming sound from your boiler. Worcester boilers can be powerful and capable of heating up far more radiators than there are in the average house. If your pump is set too high, the increased pressure could be responsible for the noise.

The first step is to check your boiler’s manual to confirm what pressure you should set your boiler should to and how to adjust it. Check the gauge on your boiler and confirm it is showing in the right zone. If it is set too high, it could cause damage to your system. Bleeding the radiators should lower the pressure to a safe level. If the pressure is too low or drops too low when you bleed the radiators, your manual will contain the procedure to increase the pressure to get it to the correct level.

If the pressure is in the correct range and you can still hear the vibrating noise, your pump may be set to too high a speed. Most Worcester boilers have either two or three different speed settings.

Please remember:

Your central heating may need the pump to be set at a certain level to be effective. Again, refer to your manual and see if it specifies the required speed.

If you can’t find it, you have two options. Firstly, you could call a plumber and ask them to check the correct levels. Alternatively, you could turn the pump down and see if it stops the noise. If it does, give it a day or so to see if the boiler is still working correctly.


In most cases, noises from your boiler will be annoying rather than a sign of a serious problem.

However, if you have any worries or don’t feel capable of checking it yourself, it is always safest to call in a plumber or trained professional.

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About the Author: AJ

AJ is a self-confessed soundproofing nut. He has written full-time on Quiet Living for the past 4 years, and has a wealth of knowledge about living a quieter life, soundproofing and fixing loud noises.

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