Samsung Refrigerators

Error Code -21°C LED LAMP

Refrigerator cannot sense outside temperature properly

Critical

Stop using immediately - risk of damage or safety issue

Also displayed as: -21°C indicator LED lamp

What This Means

Poor open circuit connection; Short circuit in sensor wiring; Temperature abnormal (above +65°C or below -50°C); Sensor connector loose

What actually causes this:

Loose or corroded sensor connection prevents proper temperature monitoring

First Thing to Check

Visually inspect external sensor connector for corrosion or loose wiring

Parts Involved

External sensorCN31 connectorSensor wiring

How to Fix

  1. 1

    1. Check voltage at both terminals of CN31 lead

  2. 2

    2. Voltage should be within 4.6V~0.6V

  3. 3

    3. Inspect for signs of moisture or corrosion on connector

  4. 4

    4. Verify wire continuity from sensor to PCB

This Error Applies To

Samsung RB12A3006 Series Refrigerators

Service manual exact match: RB12A300631/AAService manual exact match: RB12A300635/AAService manual exact match: RB12A300641/AA

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