Preheating’ means that you heat the oven to the desired temperature BEFORE you put the food in.
1. Select the desired function type (e.g. top/bottom heat with convection)
2. Select a temperature (e.g. 160 °C)
3. Switch on the oven (either ‘M’ continuous operation or set time).
When the desired temperature is reached, the pilot light goes out and preheating is complete. You can place the food in the oven for roasting/baking.
However, due to the short heating-up time, preheating is not advisable in most cases, but rather a waste of energy.