Duco4ss main oven not heating on fan setting

Question

Hi,

the main oven in my duco4ss will heat on the upper element setting but we get no heat on the fan setting. The light comes on and the temperature light shows that the oven is (not surprisingly) not at the desired temperature. I have tried using a range of temperatures but to no avail. Is it the fan element or should I try some other switches etc first?

13 coming for Christmas dinner and 12 at New Year!!!!!! Any help gratefully received
Pete