The F08 error means that the pressure switch is locked on full.
Disconnect the washing machine from the mains.
Remove the top cover.
Find the pressure switch (there is a thin tube leading to it).
Disconnect the tube, blow it down hard to check it for clogs. Check the pressure chamber. Tap the pressure switch with the screwdriver handle several times.
Reconnect the tube and run a cycle.
If the problem persists, disconnect it again and inspect the tube down to the pressure chamber.
Disconnect the chamber and rinse it out, including the tub port.
Reconnect the tube and run another cycle.
If the error persists, most likely, some parts will need to be replaced.
Most likely, the pressure switch itself is bad.
If none of the above steps works, this may be a main control board problem.