Miele CVA 615 "Water System Fault" keeps happening?

Tried the technique mentioned in some of the suggestions and for a day it worked. However, the next day, I noticed that the message came on again when the machine was turned on. So I repeated the same steps and tested the unit and it showed to be working again. But then later that afternoon, I turned on the unit and got the same message and the pan inside is again full of water like before. Could there be a missing piece to the valve on the water tank? When I am filling it up with water, water doesn't seem to be coming out until I place it back into the unit. Do I need a new water tank? or is there a website to check a diagram of the water tank to see if it's missing a part?