Ok, had to replace 'O' ring on diverter valve assy, had been chuffing out water! Now I have plenty of hot water, but the CH will not spark up at all! Model is a Biasi Riva compact HE, M96.24SM/C. Any ideas? Upon removal the motor was dry, so I suspect it is something else, Not sure what water could have affected. PCB was bone dry, fuse in PCB is ok...