I have personally witnessed Thor authorizing repairs for units far far out of warranty because the problem was obviously their mistake.
I have had Thor do warranty work on a used unit.
Be very nice to the dealer you wind up at, and watch nice things happen in return.
Also have a complete of other items needing fixed/parts ordered and get them all done at once.
I'll bet dollars to dog doo they happily fix it.
With your professional background, Why the question about repiping it?
I'm asking these things because Thor often(maybe always) routes at least one gray water source into the black tank. Just because the black tank is filling with gray water doesn't mean it's backwards.
It means it's backwards only if the gray water valve is closed and the gray water tank fills with doo.
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