Newhorizon1

That wasn't your inlet connection These is a check valve on your water inlet I think you accidently hooked you fresh water to your...

Yes there are vents by code! Was your Grey tank valve opened closed when you cleaned the black tank? Your black water might have been...

Sounds like a problem with the automatic transfer switch! You should not be getting 240v on any sockets anywhere, even the washer/dryer...