Error Code FRIDGE_DEF_HEATER
Fridge defrost heater circuit is open or shorted
Critical
Stop using immediately - risk of damage or safety issue
Also displayed as: F blinks
What This Means
Defrost heater element burned out (open circuit); Bimetal thermostat open and not resetting; Thermal fuse blown; Wiring disconnection to heater
What actually causes this:
The heater that melts frost off the fridge evaporator has burned out or its safety cutout has tripped, causing ice to build up and reducing cooling.
First Thing to Check
With the power disconnected, measure the resistance across the defrost heater terminals — it should read about 63 ohms. An open reading means the heater or thermal fuse has blown.
Parts Involved
How to Fix
- 1
Disconnect MAIN PCB CN20 connector
- 2
Measure resistance at F-DEF: CN70 '5' (BRN) ↔ CN71_1 '5' (BLK)
- 3
Expected value: 63 ohm ± 7%
- 4
0 ohm = heater short; ∞ ohm = wire/bimetal/heater open
- 5
If defrost sensor temperature is below 53.6°F (12°C), heater circuit must be checked
This Error Applies To
Samsung RF23BB89 Series Refrigerators (2023) (2023–present)
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