Error Code C-21
Oven overheating safety error — oven temperature has exceeded safe operating limit
Moderate
Address soon - your appliance may not work properly
What This Means
Oven temperature sensor failure; DLB relay stuck closed; Bake relay stuck closed; Broil relay stuck closed; Convection heater relay stuck closed; Shorted harness to PCB
How to Fix
- 1
Disconnect power and Assy Display PCB.
- 2
Check the DLB, Bake, and Broil relays on main PCB (normal resistance: infinite ohms). Also check ConV relay.
- 3
If relays are abnormal: replace main PCB or solder if PCB pattern is damaged.
- 4
If relays are OK, measure thermistor resistance (1080 ohms at room temperature).
- 5
Check the connecting condition of harness related to oven sensor.
- 6
If sensor or harness is bad: replace oven sensor or reconnect after replacement.
- 7
If sensor/harness OK, check connector and harness connected to main PCB connector CN320.
- 8
If CN320 harness connection is bad: replace or repair harness.
- 9
If all above OK, there is no problem — the replacement of main PCB resolved the issue.
This Error Applies To
Samsung NX58M9420S Series Ovens & Ranges (2015) (2015–present)
Related Error Codes
Door locking error — door lock motor or switch malfunction during self-clean locking sequence
Oven temperature sensor open circuit (resistance over 2950 Ohm) or shorted circuit (resistance under 930 Ohm)
Shorted touch keypad — a key on the glass touch control panel is shorted or stuck
Communication error — Main PCB to Touch panel or Display PCB communication failure
Communication error — Main PCB to VFD display module or Main PCB to Sub PCB communication failure