Miele Dishwasher Error Code F87

F87 indicates a break in data transfer between the sensor softener unit and the main electronic control module. The dishwasher detects that communication with the softener sensor has been lost and activates an emergency operating program. The fault can stem from a wiring break, a faulty connector, insufficient supply voltage to the sensor, or a failed sensor softener component.

The dishwasher switches to an emergency program during an F87 fault, which allows limited continued use. However, running the appliance extensively in this state is not recommended, especially in hard water areas, because the water softening system is not functioning and limescale can build up on the heating element and internal parts over time.

Repair costs vary depending on what is causing the fault. If only a connector needs reseating or a wire needs repair, costs may be limited to a service call fee, typically in the range of $80 to $150. If the sensor softener unit requires replacement, parts and labor combined can range from $150 to $400 or more. Control module replacement is the most expensive scenario and can push costs higher.

Some steps are accessible to a confident DIYer, such as inspecting connectors for loose or corroded pins and checking for visible wire damage. However, verifying the 9 VAC supply voltage at the sensor softener requires a multimeter and basic electrical knowledge. Replacing the sensor softener unit or the control module is best handled by a qualified technician familiar with Miele appliances.

A reset may temporarily clear the displayed fault code, but if the underlying wiring fault, connector problem, or failed component has not been repaired, the F87 error will return once the appliance attempts to communicate with the sensor softener again. The root cause must be diagnosed and corrected for the fault to stay resolved.