Well what info you have given is a bit vague (would be better if you quoted the Model/Serial No’s to be specific 😉 ) But usually it’s either the element at fault or you’ve accidentally got the oven timer set on ‘Auto’ maybe 💡
Thanks for the reply it is a Competence 3121 B, KD 944 181 051- 047/ 585300. Also I can confirm that it is not in auto mode and that the red light on the front does not now work.