While you wait for answers, we may have found some information which could help you.
Click here for Pilot Light Checkedthorn apollo boiler no gas coming through ?
thorn back boiler housewarmer s?
unable to light pilot on thorn m44/54b boiler?
How do I light it?
apollo boiler banging noises ?
Location of pilot light Thorn Housewarmer Super back boiler?