Symptoms
• Freezer temperature rises above the normal freezing range
• Control panel displays E21 error code
• Compressor cycles on and off irregularly
• Freezer beeps or sounds an alarm
• Frozen food begins to thaw or shows signs of partial thawing
• Interior light may flicker or behave erratically
• Refrigerator section (if combo unit) may also experience temperature fluctuations
Possible Causes
• Faulty temperature sensor (thermistor) located in the freezer compartment
• Loose or corroded wire connections between the sensor and control board
• Damaged sensor wiring from frost buildup or physical damage
• Control board malfunction preventing proper sensor signal interpretation
• Power supply voltage fluctuations on the 120V/60Hz household circuit
• Ice accumulation around the sensor probe blocking accurate temperature detection
• Failed connector or harness between sensor components
Safety Checks You Can Do
• Verify the freezer is plugged into a functioning 120V outlet and check your home's circuit breaker for any tripped breakers
• Unplug the freezer for 5 minutes, then plug it back in to reset the control board and clear the error code
• Inspect the freezer door seal for gaps, cracks, or poor closure that could allow warm air to enter and confuse the sensor
• Clean the condenser coils located on the back or bottom of the freezer to ensure proper heat dissipation
• Check that the freezer is not overpacked with items blocking internal airflow and vents
• Verify the room temperature where the freezer is installed is between 50°F and 110°F (the recommended operating range for USA models)
• Look for any visible ice buildup around the temperature sensor area and use a soft cloth to gently remove it
• Ensure the freezer is installed with proper clearance from walls (typically 2-4 inches recommended) for adequate ventilation
• Test the outlet with another appliance to confirm the electrical outlet is providing stable power
Safety First
Always disconnect the appliance from power before performing any checks. If you are unsure about any step, please contact a qualified technician.