F5 indicates the pressure switch is stuck on full.
If the machine has failed to empty the water then this would indicate a blockage.
If you have fully drained the water out of the machine, take the filter out.
Put the machine on spin or drain only programme and look/listen at the open filter to see if the pump is running.
If the pump isn't running check that nothing is jamming the impellor.
Remove the debris jamming it and try it again.
If the pump is running, check the drain hose where it attaches to the house drains for a blockage.
Check both the hose and the point it connects to.
Hope this helps
Let me know how it goes or if you need more help