I want the circuit diagram of the PCB in a Potterton 28i?

The Contol PCB part number is Baxi 248731. The board is marked Honeywell and has a No. CSO13178-LS. My third board in about five years. Flashes a fan or flue fault.

I am competent to diagnose a problem if I have the board details. Have read that these boards suffer from very fine hairline cracks in the soldering after a period of use.