The connection element of the Cappuccinatore (steam outlet nozzle) is dirty.
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Push the central spout down as far as it will go. Pull the stainless steel cover forward and off.
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Remove the dispensing unit toward the front.
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Twist the top part with the holder for the milk pipework. Pull off the top part (1).
Then pull the Y-piece off (2).
Remove the dispensing spouts (3).
Clean all parts thoroughly.
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Clean the surfaces of the central spout with a damp cloth.
If the milk pipework is blocked, clean it under running water with the brush supplied:
Insert the brush into the milk pipework.
Move it back and forth as far as it will go until all milk residue has been removed.