The connection element of the Cappuccinatore (steam outlet nozzle) is dirty.
Push the central spout down as far as it will go. Pull the stainless steel cover forward and off.
Remove the dispensing unit toward the front.
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.
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.