I am having trouble with my Diplomat ADP 4890 Double Electric Oven. The top oven is working fine but the bottom oven keeps cutting out during cooking in both conventional & fan modes and will only work again once it has cooled (as if its overheating – but the thermostats appear to be working correctly). When the top oven is running I can hear the cooling fan running but when only the bottom oven is running I cant hear the cooling fan. Should the cooling fan service both ovens? If so – what might be the problem? Thank you in anticipation.