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Central Heating Pump Pulsing: 6 Main Reasons & Solutions

A noisy central heating pump is super disturbing as it continues throbbing. That’s why you have to look for the cause of this problem as soon as possible. Otherwise, your pump can get more damaged.

Why is your central heating pump pulsing?

First of all, this issue is generally due to airlock and blockage of dirt. It’s also caused due to the speed set and seized internal components. Additionally, overheating of the pump significantly disrupts the pump. Moreover, the fan hitting other parts is quite a common issue for this problem. But these issues can surely be resolved!

This isn’t enough to fix the annoying sound. We have explained the solutions in simple words to make things easy. 

Just stick around to fix the pulsing quickly! 

6 Reasons behind Central Heating Pump Pulsing

When you switch on the central heating, the hot water recirculates to the radiators. This is what the central heating pump is responsible for. 

Now, there’s a possibility that you might think-

The causes for central heating pump pulsing and hot water recirculation system issues are the same. But that’s false! Because there are 6 specific reasons behind the pulsing of central heating pump-

Airlock Issue

An airlock is one of the causes of humming noises from central heating pumps. When air accumulates in the pump, it forms a blockage.

Many central heating pumps feature a bleed screw that may be easily cranked. It relieves the pump of surplus air and ceases the buzzing.


Switch the central heating system off. Wait for it to cool down for around 20 minutes. Place a dry cloth or towel beneath the radiator. 

Turn the valve anti-clockwise with your radiator key to slowly open it. A hissing noise will be heard as air escapes the system. 

When the hissing stops, all of the air in the system has been removed. The valve can be closed then. Make sure the valve is fixed properly, or else the pump might overrun.

Check the pressure in your boiler and switch on the heat. Then inspect your radiators for cold patches once it’s heated up.

High-Speed Set

The flow rate of modern central heating pumps can be adjusted using speed controls. The lowest option will produce a sluggish flow rate. 

But the highest setting will set a rapid flow rate. It’s critical that the setting is appropriate for your central heating system.

If the speed is too high, the central heating pump will be noisy. 


Locate the flow switch. Turn it down one level if your pump is making sounds. You have more than one flow setting to work with. 

Double-check the radiators and towel rails to see whether they reach the proper temperature. The temperature should be between 35-40 degrees Fahrenheit. 

If it reaches the proper temperature, leave it alone. Otherwise, consult with an expert.

Dirt Blockage

Water can take up sludge, rust, and debris as it travels around the central heating system. This can accumulate over time and cause system clogs within the central heating pump.

If your central heating pump is obstructed, the radiators will heat up really slowly. This might take up to 45 minutes. 


It is pretty simple to remove dust clogs. You’ll need to perform a power flush. You may do it either manually or with the help of magnetic power flushing equipment. A heavy-duty power cleansing equipment like wet extractors can also be used.

Now, you might be concerned about choosing the right extractor. For that, we’re about to recommend two of the best extractors around you!

Product 1
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You can certainly believe in these products. These are quite durable. They have the best features to be coherent with your pump.

Fan Hitting The Other Parts

To keep central heating pumps from overheating, they contain a fan. But you might hear a metal clanking noise when the pump is running at times. It’s most likely due to a fan problem, such as a loose blade.


In this case, you’re certainly going to need a gas safe engineer. Because there’s a risk of injury if you try to solve the problem. 

Plus your pump can get even more damaged. So, let an expert handle it. 

Pump Overheating

Most of the time, the issue for pulsing is due to the motor. For example, you may encounter a hot Grundfos central heating pump when you turn it on after a long time. 

Oftentimes, the motor overheating is caused by trapped air. But it may be freed with a light tap. As a result, the pump pulses.


If this happens more than thrice, it’s probably time to replace your central heating pump. You can call a gas-safe engineer near you. This would be the best option for you.

Seized Internal Components

You might be hearing a buzzing noise or feel a lot of vibrations. In that case, internal components of the pump are seized. It’s most likely the shaft of the pump. 

The energy used to turn the shaft of the pump has to go somewhere. As a result, there’s an annoying noise.


To fix this, internal parts should be freed by a gentle tap on the side of the pump. Nevertheless, you should disassemble it and then clean it thoroughly. Inspect the bearing on the shaft as well. 

If the shaft hasn’t been sitting horizontally, the bearing will have worn out. As a result, it will seize once more. Dirt is also a significant component in internal seizures.

These are the main reasons behind your central heating pump pulsing!


Question: Is it okay if my central heating pump is hot?
Answer: Central heating pumps are generally warm to touch. They are, after all, highly built machines capable of rapidly moving large amounts of water. If the pump becomes too hot to touch, something is wrong.

Question: What setting should I maintain for my central heating pump to run?
Answer: In the winter months, 18 degrees is commonly regarded as the lowest temperature. It will provide comfort. However, people react to cold in various ways. For some people, 25 degrees will be the ideal temperature.

Question: How to say if my central heating pump is no more in order?
Answer: Despite the pump functioning, the water flow pipe is not heated. From the pump, there would be water leaks. The pump would also make strange noises.


As you can see, central heating pump pulsing isn’t that big of an issue. It can be solved easily. 

Try to inspect the cause first and fix the problem accordingly. Good luck calming down your noisy central heating pump!