I recieved a replacement oven because of fan issue. I went through the different fan speeds. On medium and low, it has a loud buzz sound that makes me think its going to blow up. No one ever mentioned if this was normal, so I donāt change fan speed.
Second issue is that the fan is always spinning no matter which element is used. When selecting cook method using the oven handle.
I burned my pizza 
because I set a timer for conventional baking with top and bottom element but the oven was working in convection mode always.