Sub-Zero 550 Not Cooling: Sealed-System Repair in Sunnyvale
The refrigerator compartment was at room temperature, and food in the freezer was melting. The diagnosis recorded overheating and oil entering the evaporator, with multiple sealed-system and related components requiring replacement.
Repair at a glance
| City | Sunnyvale, CA |
|---|---|
| Appliance | Built-in refrigerator |
| Category | High-End Brands |
| Brand & model | Sub-Zero 550 built-in refrigerator |
| Repair date | |
| Customer complaint | The refrigerator compartment was at room temperature, and food in the freezer was melting. |
| Diagnosis | The diagnosis recorded overheating and oil entering the evaporator, with multiple sealed-system and related components requiring replacement. |
| Repair cost | $3,178 (parts and labor) |
| Warranty | 6 months on parts and labor |
| Outcome | Repaired |
Inspection and access
I opened the upper machinery compartment and the freezer housing of this Sub-Zero 550. The customer had reported loss of cooling in both compartments; the diagnosis identified a sealed-system failure following overheating.
Repair and reassembly
I replaced the compressor and evaporator coil, along with the condenser fan, evaporator fan, heating element, defrost thermostat and defrost sensor listed on the invoice. The photographs show the machinery area opened, the compressor connections and the equipment connected for sealed-system service.
I flushed the system, pressure-tested it, pulled a vacuum and charged it with R134a, as recorded in the completed work. Condenser-coil maintenance and reassembly were also included. The final invoice was $3,178 after the recorded adjustment.
Photos from this repair
Sub-Zero 550 with the upper machinery compartment opened. 
Refrigeration tubing and service hoses in the upper compartment. 
Digital service instrument connected during sealed-system work. 
Vacuum equipment and hoses beside the refrigerator. 
Compressor and copper tubing with the machinery panel opened. 
Defrost timer components compared during service. 
Freezer housing opened for access. 
Electrical connector inspected during the repair.
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