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How to Deal With a Grundfos Circulating Pump Making Noise

A noisy circulating pump can be an annoying experience. Circulating pumps are generally turned on all the time. So any noise generated from them can be very irritating. 

Circulating pump noises are actually pretty common. Even with popular brands like Grundfos, noises can happen in certain cases. 

Why is your Grundfos circulating pump making noise? 

Pumps can be noisy for a plethora of reasons. These include air locking, problems with the bearing, incorrect installation, accumulation of dirt, seized internal components, etc. Each problem has its own unique solution. But we need to understand what’s causing the noise for us. 

Want to know how to deal with all these problems and fix a noisy circulating pump? Let’s begin!

Why is My Grundfos Circulating Pump Making Noises

A circulating pump could be noisy for a lot of reasons. Having an idea about Grundfos pump troubleshooting, in general, is very useful. 

Here’s a list of the common reasons why your circulating pump might be making noise with solutions:

Your Pump is Airlocked 

One of the most common reasons behind a noisy circulating pump is that it’s airlocked. Quite often, air can get into the system. This creates noise from the boilers, radiators and heating pumps. 

The air needs to be bled out from the system in such cases, and you’re good to go!


Fixing an airlocked pump is pretty simple. Most Grundfos pumps have a bleed screw to remove the excess air. 

Carefully open the screw until you hear a hissing noise coming out of it. Keep the screw open until the sound stops. Wait for a few minutes and see water dribbling out of it. 

Once the water dribbles out, it means that all the air in your system has bled out. Now carefully close the screw and you’re good to go!

Incorrect Installation 

If your pump keeps getting airlocked, it probably hasn’t been installed correctly. For example, your pump shaft might not be horizontal. As a result,  it might cause air to get in and create a whining noise from the heating pump.


In this case, you have to change the position of the pump shaft correctly. We recommend that you turn off your recirculating pump beforehand.

Once the pump has turned off, adjust the shaft and the bleed screw. Make sure that the pump is horizontal and the screw is at the side. It could make a fair bit of noise even if the pump is a few degrees to the side. So, check that carefully.

Internal Components Might be Seized 

Sometimes, your pump might have a constant humming noise or vibrations coming from it. In that case, there’s a chance that its internal components are seized. 

Generally, the pump has internal components that need to move. But, if their motion is restricted, the energy is converted to noise. Deal with the seized component, and the sound will be gone.


Try finding out the source of the noise. Once you detect the part that’s making the noise, slightly tap the side of the pump a few times. The tapping should free it up.

If you want a better solution, clean the pump carefully. There might be dirt that’s blocking the pump, so get rid of it carefully.

Also, the bearing of the shaft might’ve worn out. This causes other components to not get enough space. Check the bearings of the pump, and if necessary, get a replacement.

Too Much Dirt

Your pump might get full of dirt at times and the passage might be blocked. This causes too much noise. This problem is more common if you don’t have a boiler filter in place. 

Also, if your pump isn’t fitted on the right side, it can accumulate more dirt. So, it’s important to clean and prevent dirt.


In case of dirt, you need to disassemble the pump and get it cleaned. Too much dirt can also damage the pump, so check for wear and tear.

Also, get a filter and attach it to the pump. This will catch the dirt and debris and prevent any future dirt accumulation or blockage. 

If you’re looking for a good filter, here’s our suggestion for the best out there:

Product 1
Product 2

These filters are some of the best we could find for Grundfos pumps. These will definitely improve your experience! 

Speed Setting Problem 

If your pump is old, chances are you’ve set the pump to maximum settings. Older pumps aren’t as efficient as the newer ones. So there is a bit of energy efficiency lost in the form of noise.

Generally, Grondfus pumps have three settings, and the highest setting might cause more noise at times.


The easiest solution, in this case, is to find the flow setting switch and reduce its setting. This would reduce noise as well as protect your pump from overheating

Once you’ve reduced the setting, make sure you’re still getting your required output from your pump. Running a pump on reduced settings can also greatly reduce your electricity consumption.

These are the possible reasons your Grundfos pump might make noise. Keep these in check and you can deal with the noise without hassle.


Question: How to know if my circulator pump is working?

Answer: If your pump is running, you’d feel the pump getting warm once it has started. Afterwards, it’ll get hot when water is flowing through it. If the temperature doesn’t change, there might be some problem with it. 

Question: How long do Grundfos pumps last?

Answer: If handled carefully, a Grundfos pump could last 15-20 years before requiring any repair or replacement. 

Question: Will an airlock in the pump clear itself?

Answer: Airlocks might clear themselves if the lock is small.  It’s very risky and keeping an airlock for too long can damage the pump itself. So, it’s better to deal with them immediately.

Final Words

A Grundfos circulating pump making noise can be very troublesome. Not only is the sound annoying, but it is also harmful to the pump. To make life easier for you, we’ve discussed the possible causes and fixes to a noisy pump! 

We hope you find this article helpful!