Thought I had posted this yesterday, but it doesn't seem to have
appeared.

I am replacing radiators, adding thermostatic valves, and have
installed a Magnaclean unit on my 40 year old central heating (boiler
only 5 years old).

There is a lot of sludge. Obviously removing the old radiators is
removing a lot, but I wanted advice about the easiest and/or most
effective way of clearing the sludge - what products people would
recommend etc. One suggestion has been to do a d-i-y power flush by
shutting off all the radiators bar one and running the system so the
Magnaclean cleans that section, then repeating the same with every
other radiator individually. But what would be the best product to
add - is Sentinel X800 worth the extra for example compared with
Sentinel X400. Or are the Fernox products better. And will the
sludge removers clear flux residues etc. from the work I have been
doing.

Any thoughts?

TIA

Keith