can anyone help.. i have a biasi 24s with no hot water , ive changed the diverter valve and the pcb board .. the central heating is working fine . the water from the taps are flowing fine just freezing cold . i took the microswitch off for the hot water and simulated the boiler working and the flame comes on fine .. but when i turn on the hot taps to call for hot water the piston on the diverter valve that operates the microswitch for the hot water dosent come out .... why is this .. how do i fix it?