Worcester Greenstar 25si Boiler issues

[Cunningman]

Hoping someone can provide insight on issues as we've had plumbers come out 3/4 times and not being able to diagnose.

10 yr old boiler, Worcester Greenstar 25si , hot water runs fine, when heating turns on it causes a lockout/reset required, after 1-3 times of reset it then works fine. Pressure remains steady between 1.5-2

Manual suggests replacing pcb however wanted to see if there was any other suggestions?

 

[CountryFan]

The 3/4 plumbers - are they part of a national company or different individuals? Could be several faults, my advice would be contact someone competent fixing boilers and specifically Worcester or contact Worcester for a fixed price repair if no joy.

 

[Daveydub]

What fault code does it show?