How long can a refrigerator be stored without being used?
Clean empty refrigerators should be stored upright and kept dry. You should prevent moisture building up inside the stored refrigerator - perhaps by removing the door or by keeping the door open.

The manufacturer's instruction booklet may have a section on storage.

Unused refrigerators are a potentially fatal hazard for children, who may get trapped inside. For this reason doors should be removed, locked closed or prevented from being closed (using a child-proof mechanism).