A Sub-Zero that clicks, hums, will not start or cannot cool does not automatically need a compressor. Start-device faults, electrical problems, refrigerant leaks and true compressor failures can create overlapping symptoms. The repair changes completely depending on which one is actually present.
We verify supply voltage, relay/overload or start components and compressor electrical condition first. A failed start relay can look like a much more expensive compressor problem.
Start relay / overload failure
A bad start device can prevent the compressor from starting or cause repeated clicking. If the compressor itself tests correctly, replacing the failed start component can restore operation without opening the sealed refrigeration system.
True compressor failure
A compressor can fail electrically or mechanically. Diagnosis can involve winding checks, current draw, start behavior and refrigeration-system performance. A compressor that runs is not necessarily healthy, and a compressor that does not run is not necessarily failed.
Refrigerant leak
A leak can leave the compressor running while temperatures slowly rise. Oil residue, corrosion, pressure/temperature behavior and frost pattern can help locate the problem.
What sealed-system repair involves
Depending on the failure, sealed-system work can include recovering refrigerant, repairing or replacing tubing, replacing a filter-drier, replacing a compressor, brazing connections, evacuating the system to remove air and moisture, charging the correct refrigerant amount and verifying temperatures and operating conditions afterward.
Why the filter-drier matters
When a refrigeration circuit is opened for major work, the filter-drier is part of protecting the sealed system from moisture and contamination. Proper evacuation and charging matter just as much as installing the new component.
Genuine replacement parts
We source genuine Sub-Zero / factory-authorized replacement components for these repairs. Model-specific fit and refrigeration specifications matter on built-in systems.
Refrigerant handling, brazing, evacuation and charging require appropriate tools and procedures. The system should also be leak-tested and verified after the repair.
See Sub-Zero Repair for local service.