Can anyone help with a cold radiator problem. I fitted a new bathroom radiator having drained down the system first. When I refilled the system only the upstairs radiators came on. I called out a plumber who diagnosed that the system needed powerflushing. (It's an 8mm microbore system). He did the powerflush (Cost £450) but now I have three of the upstairs radiators not working. The plumber says that when I drained down the system I must have disturbed some muck which is now blocking one of the manifolds which will need to be located and cleaned out. However we have no idea where they might be and I thought the Powerflush should have done the job anyway. The plumber charges by the hour and says it could take a long time for him to find the manifold in question and with fitted carpets & chipboard floors it will also be very disruptive. Is there any alternative to what he is suggesting? Another Powerflush is apparently out of the question.