Smeg CV10B - Manual (Page 10)

Instructions for Use 68
Thermostat settings towards min help you save energy provided that
the freezer is loaded with smaller amount of frozen foods.
Changes of the ambient temperature affects temperature in the interior
of the appliance. Choose correct setting of the thermostat knob.
Red Control Light
The red light is on when there is something wrong with the
temperature in the freezer (See Trouble Shooting Guide).