Bypass/shutoff for water supply to washer hookup

[PeteS]

Hi,

New to the forum... Nice to have found this..

We have a 2011 sandpiper 345ret. Just discovered there's water in the basement by observing that the carpet through the compartment is wet. Our unit is parked seasonally so it's not water from travel on the road.

I suspect the guy we hired to winterize the unit may have forgotten the line going to the washer. However I don't know where that runs exactly, and also not near the trailer until the weekend. Does this suspicion make sense?

Is there a plumbing guide or schematic available? Ideas where a shutoff for that line could be? Or guidance or thoughts on this?

Thanks