Noisy Central Heating Pump (& Other Problems) Explained

Noisy Central Heating Pump (& Other Problems) Explained

A noisy central heating pump can not only be a frustration it could also be the sign of a fault that needs the attention of a heating engineer.

These common central heating pump problems will help you to identify the cause and get your central heating up and running again, free from any banging, clunking or gurgling noises.

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What is a central heating pump?

When you turn the central heating on, the hot water needs circulating around to the radiators and that’s the job of the central heating pump.

Despite its relatively small size, the central heating pump has a big role to play in keeping your home warm as it efficiently pumps hot water to the radiators then back to the boiler.

Where to find the central heating pump

In most cases, the central heating pump can be found pretty close to the boiler so that it can begin pumping the water as soon as the boiler is done heating it up. Otherwise, you’re likely to find it in the airing cupboard or under the stairs.

Why a central heating pump might be noisy

As well as loud noises, an issue with the central heating pump can result in cold radiators when the central heating is turned on and even leaking.

The best thing to do if you notice issues with your central heating system is to contact a professional heating engineer but these common central heating pump problems will help you to identify the possible problem.


Central heating pump humming noises are most commonly caused by an airlock – when air builds up in the pump and causes a blockage. To stop the humming and release the air, many central heating pumps have a bleed screw which can be simply turned to rid the pump of excess air.

Blockage in the pump

As water circulates around the central heating system, it can pick up bits of sludge, rust and other debris which then travels around the pipes. Over time, this can build-up and cause blockages in the system – including with the central heating pump.

To identify if your central heating pump is blocked, it will either cause the radiators to heat up very slowly or not come on at all.

Fortunately, the fix is relatively simple as a small clean should be enough to clear a blockage from the pump. However, it’s important to take measures to prevent the pump from becoming blocked again the future.

Firstly, heating engineer will need to perform a hot flush of the system – a process which involves chemicals being sent around the system to clear it out – and, secondly, it’s highly recommended to have a magnetic filter installed.

Heating engineers will now recommend having a magnetic filter fitted to your central heating system which collects various types of debris before it has a chance to form a blockage.

Speed set too high

Modern central heating pumps come with speed settings that adjust the flow rate. Often with 3 settings, the lowest will set a slow flow rate while the highest sets a faster flow rate, it’s important that the setting suits your central heating system.

If the pump is set too fast then it could get noisy but before turning it down, you might want to contact a professional as it might be on that setting for a reason.

Fan hitting other parts

To help keep central heating pumps from overheating, they’re fitted with a fan to keep them cool. Should you be hearing a metal clanking noise as the pump operates, a fault with the fan, such as a loose blade, is likely to be the cause.

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Central heating pump hot to touch

As the central heating pump operates, it will warm up a little but if it becomes too hot to touch there’s likely to be a fault and more often than not it lies with the motor.

If your central heating hasn’t been on for a long period of time – maybe during the summer – the pump can overheat when it’s turned back on. Most of the time, the motor over heating comes down to a part getting stuck and a light tap could be enough to free it. However, if this is happening over and over again then it’s probably time to have your central heating pump replaced.

How much does a central heating pump cost?

The price of a new central heating pump can be anywhere between £80 – £200. It’s important not to just go for the cheapest one you find as it’s unlikely to last as long as the premium products which could mean you’ll be having to pay for a replacement again much sooner.

Grundfos central heating products are widely considered the best on the market and can cost £100 – £250 depending on the model.

Still having central heating pump problems?

If you’ve been through all of the common problems and still find that your central heating pump isn’t working then it might be time to question the installation. Problems with a recently fitted heat pump could mean that it hasn’t been installed properly.

In some cases, this means that it’s been fitted the wrong way round. Fortunately, this is a very rare event and shouldn’t be something you have to worry about if you hired a qualified professional.

A pump that’s facing the wrong way needs to be removed and turned around but it’s not quite as simple as it might sound. Ahead of the pump being removed, the system will need to be drained then once refitted, the system will need filling again.

Find a local heating engineer to fix your central heating pump

A central heating pump replacement means having to find a heating engineer and we’ve made finding local professionals easier than ever.

At Boiler Guide, we have a network of heating engineers across the UK and by taking a few moments to complete our simple online form, you’ll get free quotes from up to 3 based near you. With multiple quotes in hand, you can compare them to ensure you’re getting the most competitive price from the person best suited for the job.

Find a local heating engineer.


Get a FREE quote from a trusted engineer in your local area. Get a quote now.