radiator upstairs heat up every time hot water is on?

might be two things.eather a diverter valve or flow sensor which will cost u fortune.

nolan .time served gas fitter
November 2009

system not in stall`d right the return pipe from the hot water tank must be the last connection back to the boiler if not it will go through heating system, seen it load`s of times eather done by plumbers who do not know how heating systems work or diy who think they know everything and do it on the cheep.

joe smith
November 2009

thanx mate

boza
November 2009

divertor is letting by get it replaced

sean
November 2009