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Why do I have a noisy central heating pump?

The tell-tale sign of a part that needs attention is excessive noise, so your noisy central heating pump is not only an annoyance but could be a fault that needs some serious attention.

In this guide, we’ll explain the common central heating pump problems to help you identify the cause and get your boiler back to normal.

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What is a central heating pump?

The central heating pump’s main job is to push hot water around your entire heating system. It circulates the flow of hot water created by your boiler to the radiators, taps or shower.

With most central heating pumps, such as a combi boiler, they’re a component inside of the boiler so that it can immediately pump hot water to the correct location as quickly as the water is heated.

Although it is a small part of the boiler, it is an incredibly important component that plays a huge role in keeping your home warm. So, it’s very important to keep it running as smoothly as possible.

Common causes of a noisy central heating pump

Don’t worry, we’re here to help! Below is a list of common causes of a noisy central heating pump:


Airlock in the system

When your system is experiencing an airlock (when air builds up in the pump and causes a blockage) you’ll often hear a humming noise from the central heating pump.

To stop the humming noise, just release the air trapped within your system. Most central heating pumps have a bleed screw that pumps out excess air when turned.

Incorrectly installed pump

If you’ve had John from down the road fit your boiler instead of a Gas Safe registered engineer, a legal requirement for anyone who works with gas, then you may have a poorly installed pump shaft.

The pump shaft needs to be installed in a horizontal position. If you’re millimetres out, then this could skew the performance of your central heating pump significantly and cause it to break quicker.

To check if you have this issue, you’ll need to seek the help & guidance of a Gas Safe engineer to survey and correctly install the pump shaft.

Internal blockage

When hot water flows through your central heating system, it often picks up sludge, rust and other debris over time. The dirt will eventually build-up and could cause a blockage in the system, this blockage could even be within the central heating pump itself.

There’s an easy way to tell if the blockage is within the central heating pump, as your radiators will either heat up very slowly or fail to come on at all.

To fix this issue, your central heating system just needs to be cleaned by either a chemical flush or power flush - using a chemical cleaner to flow through your system and clear out the dirt, rust and debris.

If you don’t have a magnetic filter, we’d highly recommended you get one installed as the filter will catch various types of debris before it has a chance to form a serious blockage.

Flow rate too high

If you have quite a modern central heating pump, it will often come with a speed setting that adjusts the flow rate of your hot water. It usually has 3 settings of low, medium and high, but it’s important that the speed is personalised to your central heating system.

If you set the flow rate too fast then you’ll have a noisy central heating pump, just turn the flow rate speed down to alleviate the noise - if it continues, then we would recommend contacting a heating engineer for a different fix.


Seized internal parts

If you hear a humming or vibrating noise, then that’s a likely sign of a seized part internally within the central pump. A very quick fix is a tap to the pump to get it going again - fingers crossed it’s as easy as that! If it continues, then it’s likely due to poor installation or a build-up of dirt in the system which requires more attention.


Fan hitting other parts

Your central heating pump will always have a fan installed to keep them from overheating, imagine pushing through extremely hot water constantly, you’d be hot too!

If you hear a metal clanking noise as your boiler is working, then it’s likely the fan has a loose blade and will need to be replaced.

Pump overheating

If the fan in your central heating pump isn’t suffering a loose blade, then it could be due to an overheating motor instead.

In the summer months when you don’t use your heating as much, then the pump could overheat when it’s turned back on. The majority of the time, the motor overheating comes down to a part getting stuck and usually a light tap will be enough to reset it. Try this quick fix, but if it’s happening over and over again then it’s likely time to have your central heating pump replaced.

How much does a central heating pump cost?

Depending on your brand and boiler type, the price of a new central heating pump ranges heavily but on average should be between £80 – £200. Do yourself a huge favour and don’t go for the cheapest price, as the quality won’t be there, and you’ll likely be buying a central heating pump twice.

We would recommend a high-quality product range such as Grundfos, as their central heating pumps are widely considered the best and will cost you between £100 – £250, depending on the model.

Central heating pump making noise?

Let our experts take care of it with an emergency repair

If your heating pump isn’t working as well as it can, you may need to seek help from an engineer.

Our Boiler Plan Gas Safe experts will point out any work that needs to be carried out, they'll also provide a fixed price repair quote.

With our 24 hour emergency repair and 95% first time fix rate, we’ll have your heating up and running again in no time.

Book a Boiler Repair

Will I need to replace my boiler?

All boilers can be repaired as long as there are replacement parts available, but it all depends on how much you want to spend on repairing it - it will be more expensive the older your system is. When your repair will cost more than installing a brand-new boiler that's known as BER (or Beyond Economical Repair) - so it would be more cost-effective in the long run to just purchase a new energy efficient boiler.

We'd recommend you get a free quote from the engineer who will be repairing your system, or get one from us below. 

Get a fixed price quote today