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Error code reference

Samsung Range Error Code E-21

Oven temperature sensor opened (over resistance).

Samsung codesSamsung range codes

Oven temperature sensor opened (over resistance).

First step from the service manual

Disconnect electrical power to the range. Remove the upper rear cover panel. Measure the sensor resistance at room temperature. If there are any problems, replace the oven temperature sensor.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E-21 means on a Samsung range

The E-21 error code on a Samsung range indicates that the oven temperature sensor has developed an open circuit condition, meaning its resistance has risen beyond the acceptable operating range. The oven temperature sensor, also called an RTD (resistance temperature detector) or oven sensor probe, is a thermistor-type component mounted inside the oven cavity. It continuously reports oven temperature to the control board by varying its electrical resistance in a predictable way as temperature changes. When the control board detects that the sensor resistance has climbed excessively or gone completely open, it cannot accurately read oven temperature and triggers E-21 to protect against uncontrolled heating.

The most direct cause of this fault is a failed sensor element itself. Over time, the internal resistive element inside the probe can degrade or break entirely, causing resistance to spike or become infinite. This is distinct from a shorted sensor (which would read abnormally low resistance). Wiring problems between the sensor and the control board, including corroded terminals, pinched wires, or heat-damaged insulation causing an open circuit in the harness, can produce the same symptom even if the sensor probe itself is still functional.

Diagnosis begins with removing power to the range and taking off the upper rear cover panel to access the sensor wiring. Measuring sensor resistance with a multimeter at room temperature is the key test. A healthy oven temperature sensor typically reads around 1,080 ohms at approximately 77 degrees Fahrenheit (25 degrees Celsius). A reading that is significantly higher, erratic, or shows no continuity (OL or infinite resistance) confirms a failed sensor or open wiring path.

Source: manufacturer service documentation.

Common causes of E-21

  1. 01

    Failed oven temperature sensor probe

    Part replacement

    The resistive element inside the sensor probe has degraded or broken open, causing resistance to read far above normal or show no continuity at all. This is the most common cause and is confirmed by measuring resistance at the sensor terminals with a multimeter.

  2. 02

    Open or damaged wiring harness

    Wiring / connection

    The wires connecting the sensor to the control board may be pinched, corroded, or heat-damaged, creating an open circuit in the signal path. Inspect the harness along its full length after removing the upper rear cover panel, checking especially at connector ends for corrosion or loose pins.

  3. 03

    Corroded or loose sensor connector

    Wiring / connection

    The plug-in connector at the sensor or at the control board can develop corrosion or lose its retention, interrupting continuity without the wire itself being broken. Disconnecting and reseating the connector, or cleaning the terminals, may resolve this if the sensor resistance measures normal.

  4. 04

    Heat damage to the sensor from an oven overheat event

    Part replacement

    A prior overheating episode, such as a runaway broil cycle or self-clean cycle fault, can permanently damage the sensor element by exposing it to temperatures beyond its rated range. If the oven recently ran very hot or another error code occurred before E-21, heat damage to the sensor is likely.

  5. 05

    Faulty control board

    Part replacement

    In rare cases, the control board itself may misread sensor resistance due to a damaged input circuit on the board. This should only be considered after the sensor and all wiring have been confirmed good by direct resistance measurement.

See the test procedure for each cause

Frequently asked questions about E-21

What does E-21 mean on a Samsung range?
E-21 on a Samsung range means the oven temperature sensor has an open resistance fault, indicating the sensor's resistance has risen beyond the acceptable limit or lost continuity entirely. The control board uses this sensor to monitor oven temperature during cooking, and when it detects an abnormal reading, it displays E-21 and disables oven operation. The most likely cause is a worn-out sensor probe, though damaged wiring can produce the same code.
Can I fix E-21 on my Samsung range myself?
Many technicians and experienced DIYers can resolve E-21 by replacing the oven temperature sensor, which is one of the more straightforward oven repairs. The process involves disconnecting power, removing the upper rear cover panel, measuring sensor resistance with a multimeter to confirm the fault, and swapping in a new sensor. If the sensor measures correctly and wiring checks out, the repair becomes more complex and may require professional diagnosis of the control board.
Is it safe to use my Samsung range while E-21 is displayed?
You should not attempt to use the oven while E-21 is active. Because the control board cannot accurately read oven temperature, it cannot regulate heating properly, which creates a risk of overheating or inconsistent cooking temperatures. The oven baking and broiling functions should be considered unreliable until the sensor fault is resolved. Surface burners may still operate normally depending on your model.
How much does it cost to fix a Samsung range E-21 error?
If only the oven temperature sensor needs replacement, parts typically run in the range of $20 to $60 depending on the specific Samsung model, making it a relatively affordable repair. If you hire a technician, expect to pay an additional $75 to $150 or more in labor. If the control board is at fault, board replacement costs are considerably higher, often ranging from $150 to $350 or more for the part alone.
Will resetting my Samsung range clear the E-21 error code?
Disconnecting power to the range for a few minutes may temporarily clear the E-21 code, but it will return as soon as the control board checks the sensor again and detects the abnormal resistance. A reset does not repair a failed sensor or damaged wiring. The only way to permanently clear E-21 is to correct the underlying fault, which typically means replacing the oven temperature sensor or repairing the wiring.

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