Re: Diplomat ADP3300 oven
That oven is a fan oven only so, on swtiching the oven on, the fan at the back of the oven (you can see the fan through the slots at the rear of the inside of the oven) should start up and, once you have selected a temperature, the heating element (which is circular around the fan) should start to get hot. Sounds like maybe the element is working but not the fan? which would give you heat at the very back but not hot enough to cook elswhere. If the fan is jammed you may be able bump start it by flcking it around using a toothpick or similar through the slots.
The grill setting should work though as it doesnt use the fan at all, select grill and wind the thermostat up to max and it should heat. Failing thatm if neither is working, that you will have a problem that will need an engineer.