SamsungOven / RangeCode C-20

Samsung Oven C-20 / C-21 Error Code - Temperature Sensor Short / Open

C-20 (or C-21) signals the main control board detects abnormal sensor resistance (short or open circuit).

Quick diagnosis

What this code is telling you

Most likely trigger

Defective temp sensor probe

Recommended replacement

Oven Temp Sensor Probe

Diagnostic path

4 ordered checks

Part fit

Exact model number required

Safety first

Before opening the appliance

Unplug the appliance before removing panels or testing internal components. Do not bypass safety switches or live-test high-voltage, gas, refrigerant, or combustion components unless you are qualified to do so.

Read the full safety disclaimer

Root cause

Why the control reported this error

The cooking control displays this code when it detects an abnormal temperature, control, lock, or power condition. Verify defective temp sensor probe first, then inspect for wire harness shorted to chassis ground and faulty main PCB before replacing oven Temp Sensor Probe.

Symptoms

What you may notice

  • Oven will not begin preheating
  • Beeping sound plays
  • C-20 displayed on digit screen

Possible causes

Check the most likely causes first

  1. 1

    Defective temp sensor probe

    Start here when it matches your symptoms.

  2. 2

    Wire harness shorted to chassis ground

  3. 3

    Faulty main PCB

Diagnostic sequence

Work through these checks in order

Stop when you find the fault. Do not perform a step that requires skills or live testing you are not qualified to do.

  1. 1

    Check 1

    Shut off breaker to oven line.

  2. 2

    Check 2

    Unplug sensor inside upper rear cavity wall.

  3. 3

    Check 3

    Disconnect electrical power before opening panels. Measure probe resistance (standard ~1,080 ohms at 70°F).

  4. 4

    Check 4

    Replace oven temperature sensor probe.

Replacement part reference

Oven Temp Sensor Probe

Exact OEM part number

Model number required

Fitment note

The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.

Verify the appliance model before ordering.

Manufacturers can use different parts under the same error code across model families and production revisions.

Where do I find my model number? →
Search this replacement part on eBay →

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Common questions

Quick answers for this fault

What should I check first for C-20?

Start with defective temp sensor probe. If that checks out, continue through the diagnostic sequence above rather than replacing a part based on the code alone.

Does C-20 always mean Oven Temp Sensor Probe is bad?

No. An error code identifies the condition the control detected, not a guaranteed failed part. Confirm the likely causes and wiring first. The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.

When should I stop troubleshooting C-20 myself?

Stop if the next step requires live electrical testing, sealed-system work, gas or combustion service, or any procedure outside your training. Unplug the appliance before removing panels or testing internal components. Do not bypass safety switches or live-test high-voltage, gas, refrigerant, or combustion components unless you are qualified to do so.

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