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Samsung Oven C-21 Error Code: Temperature Sensor Failure Fix

Quick Answer

Samsung ovens use an NTC thermistor rated at 10K ohms at 77 degrees F - this is the most important spec to know for C-21, because it is radically different from the RTD probes used by GE (1080 ohms) and Frigidaire (1100 ohms). Ordering a GE or Frigidaire sensor as a substitute is the most common and costly Samsung C-21 mistake.

Samsung ovens use an NTC thermistor rated at 10K ohms at 77 degrees F - this is the most important spec to know for C-21, because it is radically different from the RTD probes used by GE (1080 ohms) and Frigidaire (1100 ohms). Ordering a GE or Frigidaire sensor as a substitute is the most common and costly Samsung C-21 mistake. The NTC thermistor has a non-linear resistance curve: at 32 degrees F it reads about 25K ohms, at 77 degrees F it reads 10K ohms, and at 212 degrees F it reads about 1.5K ohms - so testing the sensor requires knowing the current oven temperature to interpret the reading correctly. Samsung NTC sensors are a clip-in mount rather than the screw-in rod style used by GE, making replacement a tool-free operation in most cases. C-21 on Samsung NE63T8911SS and similar models is most commonly caused by the NTC probe itself failing, with the wiring harness as a secondary cause.

SamsungOvenSeverity: high84% DIY Success
Time to Fix
20–45 min
Difficulty
beginner
Parts Cost
$15 – $250
Tools Needed
Multimeter (ohm mode), Phillips screwdriver

What Does the C-21 Code Mean?

The NTC temperature sensor is reading outside the acceptable range. Samsung NTC sensors are rated at 10K ohms at 77 degrees F - a completely different spec from GE or Frigidaire sensors.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

NTC thermistor probe internal failure (drift or open circuit)40%
Sensor wiring harness damaged or connector loose24%
Control board sensor input circuit failure (rare)22%
Moisture in sensor connector causing resistance shift14%

Symptoms You May Notice

  • C-21 displayed on Samsung oven control panel
  • Oven will not heat or shuts down immediately
  • Code appears even when oven is at room temperature
  • Oven temperature inaccurate before shutdown occurs

Can you reset a Samsung oven to clear the C-21 code?

Press Cancel to dismiss C-21. Cut breaker power for 30 seconds. The code will return if the sensor is not replaced - C-21 is an active hardware fault that cannot be cleared by software reset alone.

Tools Required for Diagnosis

Multimeter (ohm mode)Phillips screwdriverNut driver (1/4")Flashlight

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

1

Cut power at the breaker

Cut power at the breaker. Allow the oven to reach room temperature (at least 30 minutes since last use). Locate the NTC sensor probe - on Samsung NE series ranges it is mounted on the rear oven cavity wall.

2

Disconnect the sensor connector (clip-in type on most Samsung NE

3

If sensor reads correctly

4

Install the replacement NTC sensor

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name
Samsung NTC Temperature SensorDG32-00002B · $15–$35
Samsung Oven Control BoardDG92-01099A · $120–$250

Repair vs. Replace Calculator

Appliance Age (Years)7 Yrs
Labor Approach
Our Verdict
REPAIR
Estimated Cost: $133 (Parts) vs $2200 (New Machine)

Frequently Asked Questions

How do I test a Samsung NTC oven sensor at home?
Use a multimeter in ohm mode. With the oven completely cooled to room temperature (70-80 degrees F), disconnect the sensor connector and measure resistance at the sensor terminals. Samsung spec is approximately 10,000 ohms. Readings below 9,000 or above 11,000 ohms at room temperature indicate a failed sensor. The reading changes with temperature - always test cold.
Can I use a GE or Frigidaire temperature sensor in a Samsung oven?
No. Samsung NTC thermistors operate on a completely different resistance scale than GE or Frigidaire RTD probes. A GE sensor reading 1,080 ohms would cause the Samsung control board to interpret the oven as dangerously hot and immediately trigger a fault. Only use Samsung OEM part DG32-00002B or a confirmed Samsung NTC equivalent.
Does Samsung C-21 mean the oven is unsafe to use?
Yes. When C-21 is active, the control board cannot read oven temperature. The oven will typically refuse to heat or will shut down immediately. Do not attempt to bypass or ignore C-21 - operating an oven without valid temperature sensing removes the primary safety control and risks overheating.

Related Samsung Oven Error Codes

Code: HUBSamsung Oven Error Codes: C-21, C-F2, C-24, C-A2 Complete GuideCode: C-F2Samsung Oven C-F2 Error Code: Temperature RunawayCode: C-24Samsung Oven C-24 Error Code: Lower Oven Sensor Fault

Same Fix on Other Brands

GE F3: Frigidaire F30:

Same Fix Works on These Brands

Samsung shares the same hardware platform with these brands. The diagnosis and repair steps are identical.

Samsung washerSamsung Washer 3C2 Error Code: Motor StallSamsung washerSamsung Washer 3E Error Code: Motor FaultSamsung washerSamsung Washer 4C Error Code: No Water SupplySamsung washerSamsung Washer 4E Error Code: Water Supply Fault (Top Load)Samsung washerSamsung Washer 5C Error Code: Drain Error (Older Display)Samsung washerSamsung Washer 8C Error Code: Vibration Sensor Fault

Models Known to Experience C-21 Errors

This repair applies to most Samsung ovens with this error code. Common model numbers include:

NE59M6850SS, NE63T8911SS, NE59J7630SS, NE63A6511SS, NE58F9710WS

Last verified for technical accuracy on March 14, 2026