I stopped by the dealer and told him of the experience of a high whine noise coming from a fan motor. He said had not heard of any one with this problem (I expected that) so I asked him to turn on the floor model he had in the store. He put the stove in test mode and as expected, I heard the semi-loud whoosh of air but no whine. Based on this, he scheduled a tech visit for next Monday. When I got home, I replicated his action and put my stove in test mode and to my surprise, no whine noise, only air. When I switched the stove back to regular operation, the whine returned. I adjusted the speed of the blower and the whine increased but when put back in test mode, nada. Could I be looking at the wrong culprit and it's not the distribution fan but something else? I'd appreciate your thoughts as a tech is inbound and I wouldn't mind solving this and saving him a trip.