I have a white-westinghouse oven model 203205 which cuts out if i use oven above 200deg, it will cut in again after it has cooled down, after removing the oven i found the cooling fan is not working although it is getting a voltage, also there are no holes cut out in kitchen unit for ventilation. i wondered if i need to get a new fan which will cost about £39, or if i cut out vent holes in kitchen unit can i do without the fan.