Bosch Washer Error Code F:25

F:25 means the Aqua Sensor, which is the turbidity or water clarity sensor in your Bosch washer, failed to complete its calibration of the operating point. The machine relies on this calibration to correctly assess water soil levels and control rinsing. The error most commonly occurs because the sensor lens has become coated with limescale, though wiring faults or a failed sensor can also be responsible.

A reset may temporarily clear the fault code, but if the underlying cause is not addressed the error will return when the machine attempts sensor calibration again during the next cycle. Cleaning the sensor or repairing the wiring is necessary for a lasting fix. Use the reset only as a way to confirm whether the repair was successful.

If the fix is simply cleaning a calcified sensor, the cost can be minimal, limited to a descaling product and your time. Replacing the Aqua Sensor itself typically costs somewhere in the range of 30 to 80 dollars for the part, plus labor if a technician is involved. If the main control board is at fault, repair costs can range from 150 to 350 dollars or more depending on parts and labor in your area.

In many cases, yes. Start by locating the Aqua Sensor, typically mounted in the sump area or lower drum assembly, and inspect it for limescale buildup on the optical lens. Cleaning the lens with a descaling or citric acid solution often resolves the fault. You should also check that all wire harness connectors to the sensor are secure and undamaged before attempting a cycle again.

The F:25 code typically halts or interrupts the wash cycle, so continued operation is generally not possible without clearing the fault. Even if the machine can be restarted, running it with a non-functional Aqua Sensor means the machine cannot optimize water usage or rinsing, which may result in poor wash results or excess water consumption. Address the fault before regular use.