The word “SERVICE” or a service wrench icon appears on the Sub‑Zero refrigerator display; unit may still cool but indicates a stored fault.

Safety first: Do not ignore a persistent service indicator; it may precede a cooling failure. Disconnect power before opening any panels.

Step 1 – Check basic operation

• Verify that both refrigerator and freezer are maintaining near‑set temperatures using a thermometer.
• Listen for compressor and fan operation; note any unusual noises or continuous running.

Step 2 – Power cycle

• Turn off the unit at the breaker or unplug for 5 minutes.
• Restore power and see if the SERVICE indicator clears temporarily.

Step 3 – Enter diagnostics (if available)

• Many Sub‑Zero models allow access to stored error codes via a key combination on the control panel (refer to your model’s tech sheet).
• Record any specific EC codes displayed; these will guide further troubleshooting.

Step 4 – Address obvious issues

• Clean condenser coils and ensure proper ventilation.
• Check for heavy frost on evaporator covers, water leaks, or non‑running fans.

When to call a professional: The SERVICE indicator is a prompt to schedule maintenance. Provide the technician with any stored EC codes and observed symptoms so they can bring appropriate Sub‑Zero parts.