Hi,
I just bought this item. At first, I too thought the "preheat" was stuck. Here's how I solved it:
Set to Bake (or whatever) press center of setting knob
Set temp to 450 (or whatever) press center of setting knob
Set time to 15 minutes (or whatever) press center of knob
Press the Start/Play button. Preheat will begin flashing on display
Eventually the Preheat becomes solid and stops flashing. Dumb design feature because we humans expect the Preheat light to go out once it is preheated. I've figured out that for this oven it stays on when cooking... just doesn't flash.
SO ONCE THE PREHEAT LIGHT IS SOLID, JUST HIT THE START/PLAY BUTTON ONCE MORE. Voila, timer will start counting down and all is well.
None of this is covered in the manual, which is also dumb.
Otherwise I like the product a lot.