Refrigerator displays EC20 or Service light with EC20 in diagnostics; unit may continue to cool but may also show intermittent warm temperatures.

Safety first: Unplug the refrigerator or switch off the dedicated circuit breaker before removing any panels. Use cut‑resistant gloves when working near sheet metal.

Step 1 – Verify ventilation and ambient conditions

• Ensure the unit has the required clearances per Sub‑Zero installation specs (typically several inches at top and sides, and open toe‑kick).
• Check that the room temperature is within normal indoor range (not in a hot garage or enclosed cabinet with no airflow).

Step 2 – Inspect and clean the condenser

• Remove the toe‑kick grille or upper grille (depending on model) to access the condenser coil.
• Use a flashlight to inspect the condenser coil for dust, pet hair, or grease buildup.
• Vacuum the coil thoroughly with a soft brush attachment. For heavy buildup, use a condenser cleaning brush and vacuum again.

Step 3 – Check condenser fan operation

• Restore power and observe the condenser fan motor near the compressor.
• The fan should run whenever the compressor is running. If the compressor is hot and running but the fan is not spinning, the condenser fan motor may be failed.
• Turn power back off, spin the fan blade by hand. If it is seized, noisy, or wobbly, replace the condenser fan motor assembly.

Step 4 – Monitor operation

• After cleaning and confirming fan operation, clear the error (if your model allows via service mode) or power‑cycle the unit for 5 minutes.
• Allow 24 hours for temperatures to stabilize. If EC20 returns or the compressor runs very hot with poor cooling, there may be a sealed system restriction or overcharge that requires a certified Sub‑Zero technician.

When to call a professional: If the condenser fan runs normally and the coil is clean but EC20 persists, or if you notice frost only on part of the evaporator, hissing at the cap tube, or very hot discharge line, contact a factory‑authorized technician for sealed system diagnosis.