Samsung Range / Oven C-21 / E-0A / E-24 — Oven-overtemperature error

What this code means

The oven detected a temperature above its normal operating limit outside self-cleaning operation.

Applicability

Applies to Samsung electric and gas ranges and wall ovens that show C-21, E-0A or E-24. The three codes come from the same overtemperature logic but not the same fault: C-21 is generally reported when the cavity genuinely runs hot, while E-24 more often points at the sensor circuit itself. Confirm your full model number — Samsung reuses these codes across several control-board generations.

Symptoms

• The oven shuts the heat off mid-bake and displays the code, sometimes after preheating normally
• Food burns or cooks far faster than the set temperature would explain
• In the worst cases the oven keeps heating after being switched off, and the code appears while the cavity is still climbing

Most likely causes

• A temperature sensor is reading incorrectly
• A bake or broil relay is stuck on
• Airflow around the oven vent is blocked
• The main control is not regulating heat correctly

Diagnostic logic

One question separates a cheap repair from a dangerous one: was the oven actually hot when the code appeared? If the cavity really did overheat — food scorched, the door glass too hot to touch, heat still rising after the oven was switched off — suspicion goes to a welded relay on the control board holding the element energised, and the board is the likely repair. Treat that case as a safety issue rather than an inconvenience: switch the appliance off at the breaker rather than relying on the control panel, because a control that cannot stop its own element cannot be trusted to stay off. If instead the oven was cold or only warm when the code appeared, the heat was never real and the fault is in the measuring path — the temperature probe next to the broil element, its connector, or the harness back to the board. A Samsung oven probe reads roughly 1,100 ohms at room temperature; a reading far above that, or an open circuit, indicates the probe or its wiring rather than the board.

Safe checks for the owner

1. Turn the oven off. If heating continues, switch off the circuit breaker or gas supply as appropriate.
2. Keep combustible items away and allow the appliance to cool.
3. Do not use the oven again until it has been diagnosed.

Estimated U.S. repair cost

$350–$750, depending on model, access, parts availability and local labor.