very advanced for their time. But not suitable for DIY repairs.
If you ask around your local independent Gas installers, you will probably find one (may be a more mature gentleman) who is very fond of the model and will put the time it to get it going. If you find such a person, hang onto them.
Due to its age, larger companies and more youthful menders may not be so keen.
I’ve got someone coming around on Wednesday but just wanted a heads up what it could be I’ve seen posts about faulty gas valve or fan so don’t mind paying if it’s just that because he’s talking of replacing boiler but it’s been fine for 15 years only ever had to solder dry joint on PCB before gets serviced regularly