I would test thermostat and ffd as well as other safety checks and if everything checked out then it can't possibly be immediately dangerous,how can you fail a boiler as ID for a faulty ffd when you've tested it and it's passed? A pcb is NOT a single component, 230v on a swl for ch demand does not = ignition! The ffd can, and will most likely, be 100% fine.
Even At Risk I think could be an excuse for not understanding the operation of the appliance adequately. Again 230v on a demand terminal doesn't mean the boiler is failing to utilise the low pressure sensor,flow switch,thermisters,overheat stat,flame rec,etc etc,all of which have to be satisfactory before ignition will commence in a modern combi . the likelihood is that the boiler is working fine,just stuck in CH,it's probably cycling fine off the boiler stat,probably modulating fan etc if it's got an air/gas ratio valve.
Ive had faulty selector switches on Baxis before,selecting hw only did nothing,with no programmer the boiler will fire constantly in ch and just cycle on/off its stat. So is that ID? Everything's working safely but there's a demand present where it shouldn't be?