De-winterizing our 2020 Forza 34T

[Seattle Dave]

Trying to get ready for a short trip with some friends, and am missing something in de-winterizing the water system. Following the manual, but finding that the water pump will not shut off in auto mode. Seems to me I'm missing some kind of valve somewhere that needs to be closed, but where? Tank is full, water streams from bath (including shower and toilet rinsing shower) and galley sink are fine. We have a residential refer, but do not use the icemaker, so that one is closed. Washer has never been used, so that is closed. I'm at a loss as to what else to check, and still the water pump will not shut off automatically.

Any advice greatly appreciated

[Morich]

There is one which many do miss and it is turning the diverter valve back from filling the tank to normal. This would be a first thought as when that valve is left to fill position it leaves an opening for the pressure to go out the fill port, rather than build up in the system.
Check that as a first thought, perhaps?

Also as an easy thing, look inside the fill port (connection) to see that the little check valve there has not gotten knocked sideways. It is often a white plastic disk just large enough to fit over the opening to close off flow going out but it is one a semi -weak spring and can get flipped up on the side, etc. Gently pushing in on it with something like a pencil may let if fall back into place.
If it has broken, etc. an emergency fix can be just adding a cap or plug to the port will solve the problem for a trip or so!