Pete wrote:
You are deluded.

Your method will only result in flushing the shortest part from the fill
point to the kitchen radiator. You need to:
* turn off and drain all radiators
* remove each one in turn and take it outside and wash it out with a hose
* with the radiator out, and the filling loop connected, open each


Hmm, I'm not sure this is necessary (although it is probably the most
thoughrough way of doing it).

I had a similar problem - slack plumber had never flushed the system. I
added a drain valve on the return to the boiler. On my boiler, when it
is turned off, no water can flow from the fill point to the drain (i.e.
through the boiler heat exchanger). By fitting a bit of garden hose to
the drain point, closing all rads off, then opening each in turn, I
believe I was able to flush just about the entire system, without
disconnecting any rads..

Tim.