I have an AEG Competence B4140-1 built-in fan oven which I installed about 7
years ago without problems. Twice in the last few days when switching it
off having been using it in fan oven mode, the rear fan element does not
switch off. So I have an oven, switched off, with a cooling fan gently
running and a bright red element inside the fan casing at the back. I had
to isolate the oven at the wall to kill it. Restore the power again, but
with the oven switched off, the element shines bright red again. Once the
oven is cool and I restore the power all is OK. After the first incident I
did a pyrolytic clean to get rid of gunge inside, but the latest incident is
since then.

It is on the same isolator as the electric hob which is a pain - lesson
learned.

Looks to me like a sticking relay somewhere. I cannot find a wiring diagram
online though. Anyone had a similar problem and fixed it. I am about to
delve inside the oven!

Regards
Bruce