You don't have an Extractor Fan on this Boiler, I think you are trying to say that the Burner is constantly running in Post Purge mode, this is controlled by a small Pcb in the Boiler Control panel, it has an electronic timer which runs the Burner fan for about 30 seconds when the boiler switches off. as your boiler has a LLD (low level discharge flue) the post purge was supposed to stop oily smells being blown back into the house after burner shut down, (it had limited sucess) You should be able to obtain a repalcement Post purge kit, from a specialist oil spares stockist
try Anglian Heating Components Ltd (01953) 607833
www.elanar.co.uk, September 2009
