I know not a single soul who has a convection oven, and I have not been able to get even my whirlpool man to help me with my question! Just got the thing a few weeks ago, and have never used one before. When I set it to preheat, the convection fan turns on for 5 seconds, off for 5 seconds, on and off over and over. Never stays on long enough to even get the fan up to full speed before it clicks off again. Does this the entire time the oven is on. Do they normally do this? I feel like it isn't supposed to, but the whirlpool guy was not helpful! He knew about as much as I did from what I can tell.