How do I fix error code C-21 on my Samsung NV51M9770SS?

1. undefined: Disconnect power and open back cover 2. undefined: Disconnect sensor harness from control 3. undefined: Measure sensor resistance (should be 1080Ω at room temperature) 4. undefined: Check broil, bake, and convection heater resistances 5. undefined: Check DLB relay and heater relays for proper operation 6. undefined: Check for disconnection of harness linked with Main PCB 7. undefined: Check resistance of oven sensor connector on Main PCB with harness disconnected (Normal: 2850Ω)

Samsung NV51M9770SSOvens & Range

Error Code C-21

Q: What does error code C-21 mean on a Samsung NV51M9770SS?

Oven temperature control failure - overheating Faulty temperature sensor reading; Defective broil heater; Defective bake heater; Defective convection heater; Malfunctioning relay on Main PCB; Disconnected harness

Oven temperature control failure - overheating

Critical

Stop using immediately - risk of damage or safety issue

Also displayed as: C-21

What This Means

Faulty temperature sensor reading; Defective broil heater; Defective bake heater; Defective convection heater; Malfunctioning relay on Main PCB; Disconnected harness

What actually causes this:

Stuck relay, faulty temperature sensor, or thermistor malfunction causing false high temperature reading

First Thing to Check

Measure oven sensor resistance and check DLB relay operation

Parts Involved

Oven sensorBroil heaterBake heaterConvection heaterDLB relayMain PCB

How to Fix

1
Disconnect power and open back cover
2
Disconnect sensor harness from control
3
Measure sensor resistance (should be 1080Ω at room temperature)
4
Check broil, bake, and convection heater resistances
5
Check DLB relay and heater relays for proper operation
6
Check for disconnection of harness linked with Main PCB
7
Check resistance of oven sensor connector on Main PCB with harness disconnected (Normal: 2850Ω)