To descale a steam oven, at Bosch Household Appliances we recommend our tried and tested descaler tablets for steam ovens. You can also use this for automatic coffee machines. It removes limescale depositis effectively and quickly and safely - all without waiting. Regular descaling of your steam oven can extend the lifetime of your appliance and improve its performance. Mix 2 descaling tablets with 300ml of water and pour into water tank each time. We recommend you wear protective gloves when descaling your steam oven. Take note of the steps in the user manual. We hope we've answered your questions about descaling your steam oven. Should you have more questions about descaling your steam oven, please get in touch with out customer service department at 6751 5000. We'll be delighted to help you.