Zanussi ZHF865 W Instruction Booklet page 36

The oven light fails to illuminate
The oven fan is noisy
The oven temperature is too high or low
36
The oven light bulb may need replacing see
page 34.
If the Fan Oven is set for automatic cooking
the light will illuminate when the cook time
begins.
Check that the oven is level.
Check that shelves and bakeware are not
vibrating in contact with the oven back panel.
Check that the recommended temperatures
and shelf positions are being used. See page
24. Be prepared to adjust up or down by 10°C
to achieve the results you want.