Visible mold or slime in the water tank or on the tank seals.

Safety first: Unplug the machine and remove the water tank.

• Thorough cleaning: Wash the tank with warm water, dish soap, and a soft brush. Pay attention to corners and the outlet valve.
• Disinfect: Rinse with a solution of water and a small amount of food-safe disinfectant or a coffee machine cleaning product, then rinse several times with clean water.
• Clean seals: Remove and clean rubber seals if possible. Replace if they remain discolored or slimy.
• Prevent recurrence: Empty and dry the tank if the machine will not be used for several days.