1) Scale/calc is formed inside the steamer.
Solution: Perform de-calc function.
To use de-calc function, place the steamer down with de-calc function facing up. Once de-calc door and inlet stopper are opened, invert the steamer to shake off any scale and water deposited inside the chamber.
Warning: Do not pour water, vinegar, descaling agents or other chemicals into the opening of the de-calc function.
2) Apart from tap water, you have filled other liquids / additives or descaling agents into the water tank.
Solution: Use only tap, demineralized or filtered water when filling up the water tank.