Isolate Mains Power to appliance as per TOPs P4
Gain access to the PCB (use insulation mat as necessary)

Observation:

There are 3 jumpers on the pcb.
Jumper JP01 - Re-ignite delay
JP01 ON = Delay between shutdown and re-ignition disabled
JP01 OFF = Delay between shutdown and re-ignition enabled
Jumper JP02 - NG or LPG
  O

  Jumper on for natural gas


O

 

  Jumper on for LPG


Jumper JP03 - Maximum DHW temperature
JP03 should not be present on all appliances fitted in the UK as per the manufacturer.