Meanjean73
Well-known member
Can anyone explain why the plumbing for the flush system is routed under the bathroom sink? I get they need a vacuum breaker device but why so much plumbing? Couldn’t it be routed inside the wet bay?

Ahhh, got ya. I knew someone on here had the answer.The Vacuum Breaker / Air Admittance / Backflow Preventer valve must be mounted higher than the toilet bowl by code.
The value of this forum is amazing!Ahhh, got ya. I knew someone on here had the answer.
Thanks
Link? Once you confirm this works, I will do the same. I hate plastic stuff.Never mind, I found a brass version on Amazon for $30. I’m going to give it a smash and see how it goes. I think the extremely hard water in Texas is probably the cause. However the loose fittings are probably the cause of my elusive leak I have been chasing since camper was new. Water runs down the line to the nautilus but also along bedroom wall under slide and drips into basement. Only leaks when back flushing black tank - I never made that connection.
WellCan anyone explain why the plumbing for the flush system is routed under the bathroom sink? I get they need a vacuum breaker device but why so much plumbing? Couldn’t it be routed inside the wet bay?
The vacuum breaker needs to be at least 12" or so above the flood level of the device its protecting. In this case the top of tank.Well
Actually 🤓... The vacuum breaker is typically mounted at least 6 inches above the highest point of any item connected to the waste tank, In this case the throne.The vacuum breaker needs to be at least 12" or so above the flood level of the device its protecting. In this case the top of tank.
I think we are saying the same thing. However Is the vacuum breaker protecting the tank or the toilet? Where will the backflow contamination occur?Actually 🤓... The vacuum breaker is typically mounted at least 6 inches above the highest point of any item connected to the waste tank, In this case the throne.
Yes its protecting the fresh water lines going to the tank. Although I think George and I are making the same point. The distance is referenced by the tank vs. the toilet.Its protecting the fresh water supply or the lines feeding the flush nozzle to prevent reverse flow from the tank.