snip
Dave,
You are a lifesaver ! If you live anywhere near Milton Keynes, I'll buy
you a beer, or several !
I drained the system down again and, lo and behold, the header tank wasn't
draining, so I disconnected the outlet pipe and jubilee'd a hosepipe to it
as per your instructions. Turning on the hose led to a sudden bout of
gurgling, then water started spurting out of the open valve of a
downstairs
radiator (which I took to be a good sign!).
The system refilled perfectly, better in fact than it has ever done in the
4
years that I have been living here (and I've been through the
draining/refilling routine more times than I care to remember). The smart
new rad. works well and we won't have to have cold showers tomorrow
morning
!
Thanks again,
Steve

Glad it worked for you!
Cheers
Dave R