Your Travato has an inlet on the driver’s side labeled “CITY FILL”.
It doesn’t “fill” anything, instead it bypasses your water tank and provides water to all of the plumbing fixtures using the water coming through the hose.
This sounds great at first until you consider the potential negatives:
1 It’s one more thing to have to hook up or unhook, impeding mobility.
2 If you have a leak someplace you won’t know it until you see/feel water flowing and then you have to run outside to the end of the hose to turn it off.
3 The water pressure in some campgrounds is less than the pressure from your on board water pump.
The majority of Travato (and other Class B brands) owners don’t use CITY FILL except to flush the lines and fill the Truma during the de-winterizing process.
Instead they use the water from the on board tank and only turn on the water pump when actually using water and then immediately turn it back off.
If you have the pump on and hear it running when you aren’t actually using a plumbing fixture it’s a immediate signal that you should be looking for a leak someplace.
When you are using your fresh water tank, you cycle the water in the tank and thus minimize any buildup.