Ah Ha . . .since my last post I have managed to fix mine!
I am assured by the customer service dept that it is not a design fault but as the only moving part it is subject to wear and tear.
1. Call 01293 652500 and order the correct replacement timer ( make and model no. on the underside of the toaster)
2. When it arrives don't be put off by blurb about competent electrician, I am sure it is just company insurance against idiots. I am a mid 40's housewife with no particular skills and managed it as easy as pie.
3. Undo screws holding base plate and feet in place.
4. Look carefully at position of old timer and note down position of different coloured wires.
5. Gently but firmly pull wires with their connections off from "prongs" of old timer - needed a dab of WD40 here (probably a no, no in the world of electricians)
6. gently lever off/ pull off dial from front of timer
7. Remove 2 retaining screw from front of timer
8. Take it out and put everything back in reverse order
9. Enjoy deep satisfaction from successful resuscitation of dying toaster, and say bye bye to burnt toast.
Caroline
July 2009