A variety of reasons may cause the back of a refrigerator to freeze, usually related to the condenser coils or thermostat issues. Older refrigerator models are more prone to this problem due to the location of the condenser coils on the rear of the unit. Other refrigerators may get frozen in the back if the thermostat or defrost timer is broken or damaged. Resolving this issue and helping prevent the problem in the future is possible through some troubleshooting and maintenance.
Turn off and disconnect the refrigerator from the power source.
Pull the refrigerator out from the wall. You will need assistance with this step. If the rear of the refrigerator is currently frozen, place towels on the floor and wait for the refrigerator to defrost. Immediately perishable items should be removed from the refrigerator during this time.
Remove extra dirt and dust with a vacuum cleaner with a brush attachment or a damp cloth.
Locate the condenser fan, which is usually located near the lower rear of the unit. Remove the back panel, if necessary, to reach it. Use a clean brush to remove dirt or debris from the condenser fan blades.
Check the water lines and tighten the connections on the hoses, as any water leaks may freeze and cause problems.
Contact the refrigerator manufacturer or a service professional if the problem persists, as a more serious problem with the condenser, defrost timer, motor or thermostat may exist and will require professional repair.