lads have a bit of a problem,got called out today on an ariston combi 38 he,the problem was the boiler was getting to temperature really quick but not distributing heat it is then dropping like a stone and kicking back in,it was going to first couple of rads but thats it but the return to boiler stays stone cold,the 3 quarter flow comes out of boiler straight into a inch and a quarter header with with two 1 inch circuits on it,i increased pump sizes on two circuits and still no difference,its not air locked and definately not blocked anywhere,do u think i wud need to install a low loss header?also when boiler is ramping up i felt above the pump on the return pump in boiler and it seemed to be getting hot in boiler but not outside,cud the diverter valve be open a bit and its short circuting across?i rang ariston but they werent any help,they just said there was a blockage in the pipework,any ideas wud be great,thanks
