Thermador Range Error Code F17

The F17 error code on a Thermador range indicates that the catalyst sensor has shorted. This code applies specifically to Gaggenau EB 270, 271, 290, and 291 oven models, which share platform architecture with certain Thermador units. The catalyst sensor monitors the catalytic converter component inside the oven, which is responsible for oxidizing cooking residues and grease vapors at elevated temperatures. A shorted sensor means the sensor circuit is reading an abnormally low resistance or has developed a direct electrical path to ground, causing the control board to detect a fault condition and disable normal operation.

The catalyst sensor is typically a thermistor or resistance-based probe integrated into or adjacent to the catalytic liner. When it shorts, the resistance in the circuit drops below the expected operating range, which the control board interprets as a sensor failure rather than a valid temperature or status reading. This prevents the oven from operating safely in catalytic cleaning or cooking modes.

The most common root causes include damaged sensor wiring, a failed sensor element itself, or moisture intrusion into the connector. The first diagnostic step is to inspect the sensor wiring harness for visible damage, pinching, or burns. A technician should also disconnect the sensor and measure resistance across its terminals with a multimeter to confirm whether the short originates in the sensor body or in the wiring between the sensor and the control board.