Thank you Bernii for the above solution.
I have a Miele MedicWash W3845. I used a plastic tube to channel tap water from laundry tap into the soap powder dispenser to speed up the water filling process. I usually want more water for the wash cycle than the predetermined level. Yesterday I filled it too fast and there were some water got sprayed into the washer, outside of the drum. This result in fault code F189. It just would not reset after the machine was turned off and then on.
Tilting the washing machine to drain the water from presumably a tray at the bottom of the machine had resulted in immediate success in resetting the machine.
Thanks again for the most useful tip.
Kirby
October 2014