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Error code reference

Electrolux Range Error Code C-21

Oven sensor opened

Electrolux codesElectrolux range codes

Oven sensor opened - open circuit detected in oven temperature sensor.

First step from the service manual

Check whether connector at the main PCB has been inserted, then check whether connector at the sensor has been inserted.

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

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What C-21 means on a Electrolux range

Error code C-21 on an Electrolux range indicates an open circuit has been detected in the oven temperature sensor circuit. The oven temperature sensor, also called an RTD (resistance temperature detector), is a probe mounted inside the oven cavity that continuously reports cavity temperature to the main PCB. When the control board reads an open circuit from this sensor, it means the electrical signal has been completely interrupted, preventing the board from receiving any temperature data. Without valid temperature feedback, the oven cannot regulate heat safely, so the control shuts down and displays C-21.

The sensor itself is a resistive element whose resistance changes predictably with temperature. An open circuit means the resistance has become effectively infinite, which the PCB interprets as a broken or disconnected sensor rather than a valid temperature reading. This condition is distinct from a short circuit fault and points specifically to a break somewhere in the sensor loop.

The first diagnostic step is to verify the wiring connections at both ends of the sensor circuit: the connector at the main PCB and the connector at the sensor itself. Loose, corroded, or improperly seated connectors are a frequent cause and should be ruled out before assuming the sensor or board has failed. If connectors are secure and seated correctly, the sensor wiring harness and the sensor itself should be tested for continuity to isolate the fault.

Source: manufacturer service documentation.

Common causes of C-21

  1. 01

    Loose or disconnected wiring connector

    Wiring / connection

    A connector at either the main PCB or the sensor itself may have worked loose over time due to vibration or heat cycling. Reseating both connectors firmly is the first recommended check before any parts are replaced.

  2. 02

    Failed oven temperature sensor

    Part replacement

    The sensor probe itself can develop an internal open circuit, especially after prolonged high-heat use. A failed sensor will show no continuity when tested with a multimeter, confirming it needs replacement.

  3. 03

    Damaged or broken wiring harness

    Part replacement

    The wires running from the sensor to the control board can be damaged by heat, pinching, or contact with oven components. Inspect the harness along its entire length for visible breaks, burns, or chafing.

  4. 04

    Corroded connector terminals

    Wiring / connection

    Moisture or grease exposure can cause corrosion on the connector pins at either end of the sensor circuit, increasing resistance to the point of an open circuit condition. Terminals should be inspected and cleaned or replaced as needed.

  5. 05

    Faulty main PCB

    Part replacement

    If the sensor and all wiring test correctly for continuity but C-21 persists, the main control board may have a damaged input circuit. Board replacement is typically the last diagnostic step after all other components have been confirmed good.

See the test procedure for each cause

Frequently asked questions about C-21

What does C-21 mean on a Electrolux range?
C-21 indicates an open circuit has been detected in the oven temperature sensor circuit. The control board is not receiving any signal from the sensor probe inside the oven cavity. Because the oven cannot monitor its temperature, it shuts down and displays this code as a safety measure. The fault can be caused by a loose connector, a broken wire, or a failed sensor.
Can I fix a C-21 error myself?
A homeowner comfortable with basic appliance work can start by checking that both wiring connectors in the sensor circuit are firmly seated, since a loose connection is the most common cause. If the connectors look secure, testing the sensor with a multimeter requires some technical knowledge but is a straightforward continuity check. Wiring harness repairs or main board replacement are generally best left to a qualified technician.
Is it safe to use my Electrolux range while C-21 is displayed?
No, the oven should not be used while C-21 is active. The control board cannot read the oven temperature, so it has no way to maintain safe and accurate heat levels. Attempting to operate the oven in this condition could result in overheating or uncontrolled temperature swings. The fault should be diagnosed and repaired before resuming use.
Will resetting the range clear the C-21 error?
Powering the range off at the circuit breaker for a few minutes may temporarily clear the code, but if the underlying fault in the sensor circuit is still present, C-21 will return as soon as the oven attempts to operate. A reset is useful for confirming whether the fault is intermittent, but it is not a fix. The wiring and sensor must be inspected to resolve the issue permanently.
How much does it cost to repair a C-21 error on an Electrolux range?
If only a connector needs to be reseated, there may be no parts cost at all, though a service call fee typically applies for a technician visit. Replacing an oven temperature sensor is generally a lower-cost repair, with parts in the range of $20 to $80 depending on the model. If the main control board is the cause, total repair costs including parts and labor can range from $150 to $400 or more.

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