I took the PCB back to the supplier and he replaced it. Fitted the (new) new one, reset it after the two lamps started flashing and now DHW and CH working fine.
Still need to get it checked over after removing and re-fitting the combustion chamber cover, but apart from that, all good.
Thanks for your help chaps!
Still need to get it checked over after removing and re-fitting the combustion chamber cover, but apart from that, all good.
Thanks for your help chaps!