When the word CALC appears on the display, you must descale the coffeemaker.

Descaling instructions:
Use white household vinegar (4% acetic acid) or another descaling liquid to descale the coffee machine.

Note: Never use natural vinegar or white vinegar with an acetic acid content higher than 8%, as this may damage the inside of the coffeemaker.  

1. Fill the water tank up to three-quarters with vinegar (4% acetic acid) and one-quarter of cold water.
2. Do not put a paper filter or coffee into the filter holder.
   Place the jug, switch on the coffeemaker and let it complete one brewing cycle.
   Repeat steps 1 and 2 twice to make sure no scale is left in the coffeemaker.
3. Throw away the vinegar/water solution.
4. Fill the jug with fresh cold water.
5. Let the coffeemaker complete two more brewing cycles with fresh cold water to remove any vinegar or descaler residues and scale particles. Note: If you use a liquid descaler, follow the instructions on the package, but complete at least one cycle with fresh, cold water.
6. Clean the detachable parts.

  
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