The ventilation in the cabinet is not optimum.
Check the ventilation cut-outs (1), (2), (3) (see figure).
If necessary, remove objects that obstruct the ventilation. Remove any dust.
The ventilation cut-outs must each be at least 200 cm2 in size. The air must be able to rise freely behind the refrigeration appliance.
To check the installation, contact your dealer or Miele Customer Service.