Dacor Range Oven Cooktop Error Code L30

The L30 error code on a Dacor range or oven indicates an open circuit condition in the lower oven temperature sensor, specifically RTD 1 (Resistance Temperature Detector). An RTD sensor works by changing its electrical resistance in a predictable way as temperature changes. When the control board detects an open circuit rather than a valid resistance reading, it throws the L30 fault and halts normal oven operation. An open RTD condition means the circuit is broken, providing infinite or unmeasurable resistance instead of the expected range the board uses to calculate cavity temperature.

The most common sources of this fault are wiring failures between the sensor and the control board, or a failed RTD sensor itself. Connection points are the first place to inspect, as vibration, heat cycling, and age can cause terminals to loosen, corrode, or pull apart. The wiring harness running from the lower oven sensor to the control board passes through areas exposed to significant heat, which can degrade insulation and cause wire breaks over time. A completely failed RTD element will also read as open and require sensor replacement.

Diagnosing this code correctly requires checking continuity through the sensor circuit. Start by inspecting all wiring connectors between the lower oven RTD and the control board for corrosion, looseness, or visible damage. If connectors look intact, measure the resistance across the RTD sensor terminals directly. A healthy RTD will read a specific resistance value at room temperature. A reading of infinite resistance or OL confirms an open sensor that must be replaced.