Power flushing the radiators

Thankyou for the advice,I have lots of plastic sheets and some disposable nappy changing pads to put under each radiator ????

Most plumbers will run the powerflush as Gandtea says.
However, to do a really thorough job, the entire system is powerflushed, emptied, then the radiators are removed, taken outside and powerflushed independently!
That's a huge job though, so most often it's just the ordinary powerflush!
We had the 'major' job done when we changed from a back boiler to a combi, the difference it made to the speed the heat got around the house was astonishing!
We still have our DS's old terry nappies (Ashton's Zorbit Gold, you just can't wear them out) so they were used as dribble cloths (not for the first time either)!

Its all done in situ....the only precautions required are to make sure its a VERY reputable company and they provide a guarantee that's actually worth something. If done incorrectly it can be very messy and not actually achieve anything.

AS I understand the procedure the power flush unit connects in place of the circulating pump. They then isolate all the radiators bar one, flush that one, then move on round the system.

Supply your own, if he is anything like a plumber we had about five years ago who ruined two cream carpets in our house!

I'd have thought the plumber would take care of any precautions necessary, or at least let you know in advance.

I don't think radiators can be removed from the wall and taken outside that easily!

I could be wrong but I thought that the radiators were taken outside and power flushed there. Even so you will have to put down some protection for dribbles.