We had this oven installed a few months ago. When we first turned on the convection fan it made a loud noise. It seem the fan was rubbing on the interior of the oven.  We had the tech. Come out and look at it. And said he would replace the motor and fan as the shaft wasn’t perfectly straight.
Well, they replaced the entire oven and the new one is perfect. 
We love that the bottom element is below the floor of the obit making it easy to clean.
They really stood behind their product.