The Zanussi ZRT 173W6 Refrigerator has some known problems that occur often. Here are some easy to do solutions for the problems or error codes your Zanussi might be giving you.
The appliance is not receiving power. This could be due to a power cut or a blown fuse.
The internal temperature of the appliance is higher than the desired setting.
The internal temperature of the appliance is lower than the desired setting, which may freeze contents.
There is an accumulation of frost and ice inside the appliance, affecting its efficiency.
Unusual sounds are coming from the appliance, which may indicate a problem.