Miele Oven Error Code F191

F191 indicates a short circuit detected in the heat-flow Pt1000 temperature sensor, component designation 2R30-10, or in the wiring harness connected to it. The Pt1000 sensor monitors heat flow inside the oven cavity and its resistance is read continuously by the control board. A short circuit drives the resistance reading abnormally low, making accurate temperature control impossible, so the oven triggers this fault code to halt normal operation.

It is not recommended to operate the oven while F191 is active. The fault indicates the heat-flow temperature sensor circuit is short-circuited, meaning the oven cannot accurately monitor or regulate its internal temperature. Continued use risks overheating, potential damage to other components, and unsafe cooking conditions.

A power reset may temporarily clear the F191 code from the display, but the fault will return as soon as the oven attempts to read the sensor again if the underlying short circuit has not been repaired. The short circuit in the sensor or wiring harness is a hardware fault that cannot be resolved through resetting alone. The defective component or wiring must be diagnosed and corrected to permanently clear the code.

A knowledgeable DIYer comfortable with electrical testing can inspect the wiring harness for visible damage and test the Pt1000 sensor resistance using a multimeter. If the sensor reads close to zero ohms when disconnected, the sensor needs replacement. However, if the wiring harness is routed through areas that are difficult to access or if the control board connections need inspection, professional service is advisable to avoid further damage.

Repair costs depend on what has failed. Replacing the Pt1000 sensor typically falls in the range of 50 to 150 dollars for the part alone, while professional labor adds to that total. If the wiring harness requires replacement or repair, costs may range from 100 to 300 dollars or more depending on the extent of the damage and regional labor rates.