Squeaking Radiator Valves: Differential Pressure Regulator Installation in Open Systems

The so-called bypasses per pump, you can also use Wilo pumps with variable power, i.e. the more thermostatic valves are closed, the power gradually decreases.
I would advise opening one of the radiators without a thermostatic head (a small radiator, e.g. a bathroom radiator, because it is always too cold there). The central heating circulation pump must have a small circulation.
I also guess that you have 2 separate pumps - for CO and DHW ...

Pumps with variable characteristics are used for thermostatic heads.

If you have gears with it, reduce it to 1 and see if the radiators are heating all the way to the bottom. The permissible difference between the top and the bottom of the radiator is 10°C. If the difference is greater then 2nd gear.
It's all about having the pump run at the lowest speed possible, then the squeaking will be minimized.
I would advise you to remove the head on one radiator and unscrew it to the max or replace the pump with variable characteristics ...

Added after 4 [minutes]:

1. Right now, this pump is probably with variable characteristics. So you should have some kind of potentiometer so turn it up a bit.
2. Take a test. turn off the valve after or before the pump and watch these 3 diodes. As the power decreases on the LED indicator, the pump is with variable characteristics, do the tip from point 1.

And if 1 radiator is turned on to the max, it also squeaks / squeaks others?

What brand are the thermostats?
Orifices on the valve under the head are set to max? Maximum number or N - neutral...

I have the same problem with these valves. If they're not fully open, sooner or later they wake up and start tapping.

Apparently that's the valves. Closing up and having a small gap, they start to vibrate with a high frequency (they have play) or hum (like an ordinary faucet). It all depends on the construction.
Maybe the problem would be solved by a new pump with electronics, but whether it makes sense to invest is your business.

In my case, the valves close and open at a low frequency of about 2 Hz.

Check that the head is touching the gland stem.
Maybe the pre-adjustment knob needs to be set / unscrewed (too much play)?

There seems to be some leeway in them Possibly a worn spring. It just has to be something else for all the valves that work like this...

In general, for me, the use of thermostats is nonsense ... I prefer, for example, to maintain a lower temperature in the central heating system

Of course, with a grain of salt
the room controller is also good, it gives big savings at night..
And are the squeaking of thermostats so annoying?

BILGO wrote:

In general, for me, the use of thermostats is nonsense ... I prefer, for example, to maintain a lower temperature in the central heating system

This is not always possible. When you live in a building heated from the municipal heating network, without thermostats you could even be in Saudi Arabia inside, even where there is weather automation (despite the automation, it often overheats a lot). Without such valves, in severe frosts, it can be hellishly hot inside (especially with a bad heating curve). It is different when you live in a cottage and have individual heating.

Noise in the valve is caused by too fast water flow and possible air in the system. If the pump is too "big", the phenomenon of noisy installation can arise anywhere... For example, sharp elbows, radiators or valves.
Someone is giving good advice. You need a bypass downstream of the pump with adjustable flow.
I remember the case that the investor "got used to" the noise in the installation. In his installation, the pump was replaced, some of the thermostatic valves and nothing helped. After some time, the decision was made to add underfloor heating. The 3D valve and the distributor pump have arrived. After this operation, the whole installation "quiet" ...
The pump issue power adaptation looks like you have to delve into the manual. Adaptive pumps usually have the option of constant operation with different flow rates (gears) and automatic operation. Then the pump, after starting, needs from a few to several hours to "learn", i.e. adapt. After this period, her work stabilizes. It is not advisable to turn the pump off and on cyclically (e.g. room regulator).

I have a WILO Pico yonos and it reacts almost immediately to changes in the flow resistance in the system. He does not need several hours to study.
You only need to pre-set the expected head to which the pump optimizes its power

Highly recommended pump.