34Operating NoisesNoises which are entirely normalThe chill cabinet is cooled by a compressor(refrigeration aggregate). The compressorpumps coolant through the coolingsystem, producing operating noises. Evenwhen the compressor cuts out, noises cau-sed by changes in temperature and pressu-re are unavoidable.This appliance is fitted with a quiet com-pressor and a low-noise cooling circuitdesigned in line with the latest technicaldevelopments.However, a certain level of noise, depen-dent on the size of the appliance, is inevi-table. Operating noise will be most audibleimmediately after the compressor cuts in. Itbecomes quieter as the operating periodcontinues.Noises which are not normalUnusual noise is normally the result ofimproper installation. The appliance mustbe installed or built-in so that it is level andstable. Under no circumstances musttubing come into contact with a wall,other furniture or with another tubing.Where the appliances are installed inopen-plan kitchens or in partition walls,the level of operating noise will be heardmore acutely. However, this is due to thesurrounding architecture and not to a faultwith the appliance.Description Cause NotesDroning Cooling aggregate Normal operating noise of the cooling aggregate.The level is dependent on the size of appliance.Humming Fan Normal operating noise of the fan.Gurgling Cooling circuit Normal operating noise as coolant flows throughBabbling the circuit.MurmuringHissing Cooling circuit Normal operating noise as coolant is injected intothe condenser.Rattle Shelves, contents Arrange the shelves and contents so that they are fixedand not touching one another.Cracking Housing Normal as materials expand and contract causedby temperature variations (e.g. plastics, insulation).