SubZero Refrigerator Freezer Error Code 80 – How to fix? by KatyApplianceRepair.com  

Sub-Zero error code EC 80 indicates
high differential pressures or low voltage at the variable-speed compressor. Below is a quick reference
and troubleshooting guide for this code.

Quick Reference

Error Code	Meaning	Severity
EC 80	Variable-speed compressor — high differential pressures or low supply voltage	High

Cause & Solution

Cause	What to Check	Fix
Suction pressure too high or discharge pressure too high	Check refrigerant pressures with gauges (certified technician)	Correct refrigerant charge; inspect for restrictions in the sealed system
Low supply voltage to the compressor inverter	Measure voltage at the compressor terminal block	Verify household supply voltage; inspect wiring for voltage drop