Simon Elliott was thinking very hard :
Is there anything I can do with this valve without draining the whole
system?
Just a suggestion with no idea of its worth....
Could you try turning the valve down at the other end of the rad to
reduce the flow a little - that might prevent the clunking.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk