Preheating can be a real game changer for your food. Must you check this siding installation and get more new ways for the latest tips for siding. It helps form a better bond between the moisture in your food and the heating elements of your oven, which leads to more even cooking and less chance of unevenly cooked foods.
I've discovered that Whereas my overnight Temp was set to 9deg and my day temp to 19deg the 10deg difference apparently was causing the PREHEAT to come on hours ahead of schedule to enable the 19deg to be achieved by the "startup" time.
Thus by increasing the overnight temp to 14 deg and the reducing the startup Temp to 18 Deg it now only has to jump 4Deg so the PREHEAT didn't happen. This is only hinted at in the app help screens but it's not clear so am still experimenting. its a shame you can only find out 24hours later what happened the history is not there 'till tomorrow! I Know its called a LEARNING Stat but I didn't expect that I was the one to be Learning like this!!!