US Patent 7089752 Refrigerator and defrosting method thereof

A refrigerator and a defrosting method thereof which are capable of achieving an appropriate defrosting operation even when a part of constituent elements included in a defrosting system fails. The defrosting method includes the steps of determining whether or not a predetermined first defrosting completion condition is usable, if the predetermined first defrosting completion condition is usable, executing a first defrosting mode, which uses the predetermined first defrosting completion condition, and if the predetermined first defrosting completion condition is not usable, executing a second defrosting mode, which uses a predetermined second defrosting completion condition different from the predetermined first defrosting completion condition, and a defrosting execution determination condition different from that of the first defrosting mode.