Samsung Oven Error C-21

⚡ Quick Answer: The Samsung Oven error C-21 indicates a malfunction related to temperature sensing, typically caused by a faulty temperature sensor or control board i... ✅ DIY Fixable

What Does Error C-21 Mean?

The Samsung Oven error C-21 indicates a malfunction related to temperature sensing, typically caused by a faulty temperature sensor or control board issue. Symptoms include the error code appearing on the control panel, the oven overheating or failing to maintain the set temperature, and incorrect internal temperature readings. If you hear a buzzing sound, it may further confirm the malfunction. Proper diagnosis and repair are essential to restore normal function.

Common Symptoms:

  • Error C‑21 displayed on control panel
  • Oven overheats or continues heating past set temperature
  • Oven fails to maintain or correctly read internal temperature

Possible Causes

  • Temperature sensor (thermistor) malfunction or abnormal resistance (medium)
  • Control board/regulator relay stuck or malfunctioning (medium)

How to Fix Error C-21

DIY Fix Basic oven reset and observation

  1. Turn off the oven and disconnect power (unplug or switch off at breaker)
  2. Wait at least 10–30 minutes for internal components to reset and cool
  3. Restore power and attempt normal operation to see if error persists

Technician Only Inspect and test temperature sensor and control board

  1. Disconnect oven from power supply
  2. Access the oven’s interior sensor (typically at the back of oven cavity)
  3. Visually inspect sensor and wiring for damage or loose connections
  4. Use a multimeter to test sensor resistance against expected values
  5. Check control board for signs of burnt components or stuck relays that may cause continuous heating
  6. Replace defective sensor or control board as identified

Parts needed: Temperature sensor (thermistor), Control board/PCB

🛑 When to Call a Pro:
  • If the oven repeatedly overheats during use
  • If error persists after reset and basic inspection
  • If you are not comfortable performing electrical tests or part replacements

Next step

Choose the next step for C-21

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Other parts options

Check related components first; use model search as a fallback.

Possible related component

Main Control Board

The central brain of the appliance that controls all components, cycles, and timings.

$120 - $280 · Medium · 20-40 mins

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Model number required

Model-compatible Oven parts

Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.

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Optional routine care

Maintenance supplies

These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.

Maintenance supply

Non-Scratch Cooktop Cleaner

A routine surface-care product. Confirm that it is approved for the specific glass, ceramic, enamel, or stainless finish.

View maintenance supply
Diagnostic tool

Oven Thermometer

A diagnostic aid for comparing cavity temperature during a controlled check. It does not prove which internal component has failed.

View maintenance supply

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Technical Specifications

note The previous model-independent part specification was removed. Verify the full model number and diagnosis in the manufacturer's official parts catalog before ordering.
part_number None

Common Questions

What does C-21 error mean on Samsung Oven?

C-21 indicates a temperature sensor malfunction, causing overheating or incorrect temperature readings.

Can I fix Samsung Oven C-21 error myself?

Yes, you can perform a basic reset by disconnecting power for 10-30 minutes and observing if the error persists.

How much does it cost to fix C-21 error?

Repair costs typically range from $50 to $300, depending on parts and service needed.

When should I call a technician for C-21?

Call a technician if the oven overheats repeatedly, the error persists after a reset, or if you're uncomfortable with electrical repairs.

Sources & References

Data last verified: 2026-07-31

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