The oven is about four years old. There was a power cut earlier in the day but it seemed to be working fine after that. The trouble started when I was trying to correct the time. But If I did anything wrong, I don't know what that was.
Hello Michael - Switched off at the mains - twice! - but no improvement. The display still shows - - - C as soon as I turn on the function knob.
I have been a while in replying because I've been thinking about what you said. I can now see you are quite right. The timer mechanism is broken - absolutely. I was looking to your suggestion of getting a new clock control item but I see from the Ignis website none of their current timers are compatible with my model.
So, as you suggested might be necessary, I have now decided to buy a new oven.
Thank you for your help. You were clear - and, sadly for me, right in your diagnosis.
J S E