You make conflicting statements...
why is my fan oven working - and - fan oven not working
I guess you mean the fan spins but the oven doesn't heat.
There's often a light on the front that indicates that the oven has not yet reached its set temperature - if this light is ON it suggests the heating element is defective - if the light is OFF it may suggest a defective thermostat.
A domestic appliance engineer may be required.
Peccavi, March 2009
