Answer Nanny, for this style wall oven, 20 to 30 minutes to pre-heat the oven is about "normal. This wall oven has a 4.3 cubic foot oven cavity, and hidden bake elements. It takes a few extra minutes to transfer the heat from the bake element to the cavity, then to heat, the larger oven cavity takes a little longer as well. 30 minutes to properly pre-heat the oven is about the average time needed. Thanks, Read More... Answered by AppliancePartsPros.com | Wednesday, November 11, 2020