Dacor Range, Oven, Cooktop Error Code L21

L21 is an over-temperature fault for the lower oven, triggered when the cavity temperature exceeds 890 degrees Fahrenheit during a self-clean cycle. The control board monitors the lower oven RTD sensor continuously during cleaning, and when the reading crosses this threshold the fault is set and the cycle is terminated. It is a safety protection feature designed to prevent damage to the oven and surrounding structure.

Disconnecting power to the oven for several minutes may clear the displayed fault code, but it will not correct the underlying problem that caused the over-temperature condition. If the root cause, such as a faulty sensor or stuck relay, is still present, the L21 code will return the next time a self-clean cycle is initiated. A reset should be used only as part of a diagnostic process, not as a fix.

Repair costs vary depending on the failed component. A replacement lower oven temperature sensor typically runs in the range of $30 to $80 for the part, while a replacement control board can range from $150 to $400 or more depending on the model. If professional labor is needed, expect to add $100 to $200 or more for diagnosis and installation. Getting a firm quote after diagnosis will give a more accurate total.

You should not attempt to run another self-clean cycle until the underlying cause has been diagnosed and repaired. Normal baking and broiling at standard cooking temperatures may be possible depending on the fault cause, but if a stuck relay or shorted element is involved, continued use carries a risk of uncontrolled heating. It is best to have the oven inspected before operating it again.

Start by testing the lower oven temperature sensor with a multimeter. At room temperature the RTD sensor should measure approximately 1080 to 1100 ohms. If the resistance is significantly off, replace the sensor. If the sensor tests correctly, the next step is inspecting the control board for signs of relay damage and checking the wiring harness between the sensor and the board for loose or corroded connections.