check the microswitch on the cold water inlet, may be sticking after tap turned off, (will stop htg working) which should then mod. down thru thermistor.
its one that you get if you ask nicely when you go on there training course
and yes the way to get the pins position is when you get a replacement pcb you get a seet with em listed.
By the way Im having a look at the new Logic boiler tomorrow