Help with Coachmen "Water Works" panel

Travelin2 wrote:
I'm not sure about the venting of the tank and am a little nervous about pumping into the tank anyway until I know how it's vented. I'm sure it is, I just don't know where it is so I can watch for it to start spitting when the tank is full.

I would be shocked if the vent/overflow outlet isn't someplace underneath the motorhome. It certainly is on my Coachmen motorhome. Once it starts piddling on the driveway, I turn off the water hose. It would make no sense at all to vent it somewhere that water spitting out would be reasonably expected to cause trouble, such as inside somewhere, since filling or even sloshing after the tank is full could cause some water to burp out.