Miele G 879 SCVI Operating And Installation Instructions page 72

Plumbing
Venting the drainage system
Only if the dishwasher drain hose is
connected to a floor drain or to a
drain pipe that is below the level of
the lower baskets wheels, the drain
must be vented; otherwise the water in-
side of the dishwasher may siphon out
during the course of a wash pro-
gramme.
Vent the drain:
Open the dishwasher door:
Cut off the vent cap located at the
right rear of the dishwasher, behind
the filters, as illustrated.
72