the fan in the grill doesnt come on causing overheating and cut out after
approx 5 min.fan comes on when top oven is used in same compartment
what could be problem please?
Most likely the control selector switch for the grill is faulty (if electrical), not sure if its a Gas grill or an Electrical grill as you don’t say.
Its advised to have a Gas Safe Engineer work on a Gas appliance.