We recommend preheating for 10 - 15 minutes to allow the Stone to reach optimum temperature. Remember to keep your pellets topped up throughout this preheat time. It is also important to leave the door and hopper lid on throughout your preheat and to remove the chimney cap as Kristian shows here:
After 10-15 minutes, you should see rolling flames inside Uuni and your Uuni is ready to cook. To maintain these temperatures, continue to top up as you cook and only remove the door when adding or removing food.