Gaggenau Oven Error Code E122

E122 indicates that the core temperature sensor in cooking compartment 1 has reported a resistance below 1 kilohm, which the control board identifies as a short-circuit condition. This sensor is the KTF food probe sensor, and at normal room temperature it should read approximately 50 kilohms. A reading far below that threshold points to a fault in the sensor itself, its wiring, or its connector. On units with software version 1.20 or earlier, this error may not appear on the display even when the fault is active.

It is not recommended to continue using the oven while E122 is active. A short-circuited temperature sensor means the control system cannot reliably monitor cooking compartment temperature through that circuit. This could affect oven performance, automatic cooking programmes, or safety-related temperature monitoring. The fault should be diagnosed and resolved before returning the oven to regular use.

Repair costs vary depending on the root cause. If the fix is as simple as cleaning a corroded connector, costs may be limited to a service call fee, which typically ranges from roughly $100 to $200 depending on your location. Replacing the KTF temperature sensor itself generally adds parts costs on top of labor, and total repair bills for sensor replacement on a Gaggenau unit commonly fall in the range of $200 to $500 or more. Control board replacement, if required, would push costs higher.

A knowledgeable DIYer can perform initial diagnostics by visually inspecting the sensor probe, its wiring harness, and the connector for obvious damage or corrosion. Resistance testing with a multimeter against the known reference values (approximately 50 kilohms at 25°C and 8.77 kilohms at 70°C) can confirm whether the sensor has failed. If the sensor is confirmed faulty, replacing the KTF temperature sensor is the recommended repair. For accessing the service test programme and diagnosing deeper wiring or board issues, a qualified technician is advisable.

A power reset may temporarily clear the displayed error, but it will not resolve the underlying cause. If the KTF sensor or its wiring has an actual short circuit, the fault condition will return as soon as the oven runs a temperature check cycle. A proper repair, whether cleaning the connector, repairing damaged wiring, or replacing the sensor, is required to permanently resolve E122.