Baxi 130 he "LD" error?

I have an 7 year old Baxi 130 HD. Today it decided to give me the "LD" error.. the book left by installer says overheat lockout.. In that section is says test black stat on flow pipe, done and thats fine with continuity across it. Then main PCB check there and no continuity so says replace main PCB..
Is that all I can do ?? a board change, anything else to check or at best anywhere to get the pcb repaired..
thanks