Only just got the heating sorted 
the new valve went on a treat 
but I then had a blockage from the cold feed (header tank) :mad:
after a few hours of backfilling through the vent pipe, poking bits of wire down various Compression joints, draining/filling/flushing, balancing the flow etc I have finaly got everything running again.
just need to get some inhibitor in tommorow (when the DIY stores are open again) :rolleyes:
wife not impressed with the chaotic state of the spare bedroom and attic … even though I’ve probably saved us something like £400 for a powerflush :shrug: women eh
yep … job for tommorow, when the store opens (a 2 minute walk to B&Q 
)