I own the 2011 RLX 262, if the floor plan is the same, when you enter the door at the rear of the unit there are 3 drawers located directly to your right under the sink, black arrow pointing to location. In mine the water pump is located under the bottom drawer. If you pull the drawer out the pump is located right there.
"Never forget the trip is as important as the destination"
2014 Ram 3500 Laramie 4X4 CTD
2011 Dutchmen Denali 262 RLX