Hi I am a registered rated member tradesman but plumbings not my forte! I have a friend who had a radiator that was,nt getting hot so had plumber in to replace it, now all the upstairs rads wont fill or heat up, my guess is either an air , blockage or perhaps theres a hidden motorised valve somewhere thats closed. Just wondering if any plumber have experienced anything similar and possible cause and fix please? Thanks Peter
