Bosch

Basically ?F? means ? filling fault so something is wrong the water level, if you want to try fixing it yourself you need to do a test on your dishwasher machine.

To start testing, press both ?SCRUB WASH? and ?DELICATE/ECONO? buttons a second time. When testing has ended, Cycle Countdown display will show a fault using codes below. If more than one fault occurs, code numbers will be added together, (e.g.?6? = faults 2 + 4).
0 = No faults detected
2 = Heating fault
8 = NTC (temperature sensor) fault
1 = Aqua Sensor ("Sensotronic") fault 4 = Filling fault F = Filling fault (display occurs during wash, not test).

To check for heater, high limit or flow switch problems, start testing until heating starts. Using a meter with a current coil, measure current going into dishwasher. If current is ~ 11 A, then heater, high limit and flow switch are OK. If current stays at ~ 1.5-2 A, then heater, high limit or flow switch are faulty.
If water level switch (f1) has failed (opened), display will show fault code "4" and unit will continually fill and drain where testing won't be completed. If flow switch (e5) has failed (opened), display will show "0", water won't heat (to 150?F) and water won?t stop circulating. If NTC probe (f2/f4) has failed (opened), display will show fault code "8" immediately and testing will end shortly after water has started circulating.


Good luck

f is fill fault to much or not enough water or water in the sump white plastic base the f code will not go away until you solve the problem when the f code shows up the drain motor will run all of the time