On my 2014 A122, I had a similar issue when I went to use water from the tank for the first time. Found a closed valve under the sink between the tank and the pump, right beside the low point drain. FWIW, my unit was winterized (delivered to Colorado in March).
The dealer did not install the water filter element in the filter (and suggested that I think twice before installing) casing, although they did show me how to do it on the PDI. After reading the horror stories on this forum, I have never put the filter element in, and will leave the filter casing untouched until I get around to bypassing it or installing a different filter.
2014 Rockwood A122