Rusty heating water with discolorations discovered.

There are also sludge separators without magnetic function, that should be noted.

That's right, but it doesn't make sense to do without the magnet.

And who is supposed to pay for that?
.

Since it is not a defect, it is up to you. But as others have already written, you don’t have to tear everything out just because of 1-2 pipes. A skilled craftsman can manage without resorting to a demolition hammer.

Mycraft wrote that it is sensible to have the pipes replaced,

Sensible: yes
absolutely necessary: no

But yes, sooner or later there can be a reduction in function and blockages. But not necessarily.

Hello

a microbubble and magnetic sludge separator is now being installed for us free of charge.

Last Monday, heating water was taken for analysis. The water was clear. So the orange or rust-brown stuff can only have settled on the flow rate tubes, right?

I ask for your opinions. Steel pipe was only installed from the basement up the chimney to the distribution box on the upper floor and from there only further to the towel radiator in the bathroom and back. Otherwise diffusion-tight plastic pipes.

Many thanks.

Great result! And thanks for the feedback!

The orange/rust-colored stuff settles on the interior walls of the system, that is, on everything inside.