WD200S overfills with water

Question

I have a Splendide WD2000S Washer/Dryer in my RV.Yesterday, it filled with water but didnt stop filling - so much so that it overflowed thru the external Air Vent.I had to keep setting the machine to the drain cycle (about a dozen times) to get it to empty.Thinking it was perhaps a one-off, we tried again and the same thing happened.Any ideas please?Rob