Sub-Zero Refrigerator Problems – How to fix? by KatyApplianceRepair.com 

If your Sub-Zero refrigerator or freezer is not performing as expected,
start with the basics below before scheduling a service call.

Common Issues & Quick Fixes

Problem	Possible Cause	What to Try
Unit not cooling	Dirty condenser, blocked vents, or door left open	Clean the condenser coils; verify vents are unblocked; check door seals
Ice buildup in freezer	Defrost system malfunction or damaged door gasket	Inspect the door gasket; if frost is excessive, a defrost component may need replacement
Water leak on the floor	Clogged drain line or faulty water inlet valve	Clear the drain line; inspect the water supply connection
Unusual noises	Condenser fan obstruction, compressor vibration, or ice in evaporator fan	Check for debris near fans; if noise persists, schedule diagnostics
Error code on display	Various — see our error code index	Look up your specific code for targeted troubleshooting