AEG 5701-4-M Overheating

Model No D5701-4-M
Product No 944171272
Serial No 51100027

Using oven, after about 1/2 hour LED display went blank. Hot air was being blown out between grill and controls. Opened oven door – fan at back was off, oven seemed rather hot – so switched oven control knob to off, but left cooker power on for case fan to disperse heat.

After about 5 mins, the display came back on, showing 12:00_.

About 5 mins later, I noticed a hot smell, and looked in oven – back of inside of oven was glowing red hot, and oven fan was not going.

Soiled underwear, switched off at mains, and left to cool down.

I am concerned that if I had not been nearby, the sod might have set light to my kitchen, even though the oven control knob was set to off.

About an hour later, tried oven again – all appeared normal, with oven fan running, and oven gaining temperature – did not leave it long enough to reach target temp (180C).

Any thoughts?

Thank you.