Error Code 12
Freezer could not complete a defrost cycle — ice buildup will accumulate over time
Critical
Stop using immediately - risk of damage or safety issue
Also displayed as: Left - ⑦ LED ON
What This Means
Defrost heater failed to reach setpoint within 70 minute limit; Defrost thermistor sensor failure; Heater element open or shorted; Excessive ice buildup on evaporator; Thermal fuse blown; Relay or contactor failure
What actually causes this:
Burned-out defrost heater, blown thermal fuse, or open wiring to heater
First Thing to Check
Disconnect CN70 and measure resistance across heater leads (Brown/Black); check for open thermal fuse
Parts Involved
How to Fix
- 1
After separating MAIN PCB CN70 wire from PCB, read resistance between CN70 Brown and Black wires
- 2
If 0 Ohm: heater is shorted
- 3
If open resistance (∞): check wire or thermal fuse for open circuit
- 4
Run forced defrost cycle and monitor time to reach setpoint
- 5
Check defrost sensor voltage (should be 3.1V minimum)
This Error Applies To
Samsung RS25J5008S Series Refrigerators (2014) (2014–present)
Related Error Codes
Ice maker has failed its automatic cycle three times in a row
Serial communication between main controller and display panel has been lost
Freezer compartment thermistor is open or shorted
The damper air-door heater circuit is open — refrigerator temperature control may be affected
Ice maker temperature sensor open/short or disconnected
Inverter-driven compressor cannot start or is being protected from abnormal electrical condition
Ambient temperature sensor open or shorted — affects defrost timing and efficiency
Refrigerator compartment thermistor open or shorted