most of my radiators upstairs fail to heat up when the boiler is on. All of the radiators downstairs are fine. When I turn all the rads off downstairs to boost the ones upstairs the boiler sends water up to the feeder tank in the loft which is consequently thrown outside via the overflow pipe. Ive drained the system a couple of times and put in sludge removal in case there was a blockage but to no avail. Any ideas?????????????

Chris from Coventry, January 2007

sounds like a bad blockage to upstairs circuit, if you can't shift it with the chemicals the next option is a powerflush with stronger chemical. which is done under more force, but cost a few hundred pound to have done. or drain the whole system remove an upstairs rad and connect a hose and see if you can locate or shift it with mains pressure

hi-spec plumbing, January 2007