Last year I had the flush system atmospheric vacuum breaker/check valve blow water between the bedroom and bathroom walls when trying to flush the black water tank.
The proximal cause seems to have been a stink bug that managed to crawl into the vacuum breaker, preventing it from closing off properly when pressurized.
I vacuumed the water off the floor, cut a hole in the bedroom wall to access the valve (!), cleaned it out and tested it, then put everything back together.
The particular flushing system I have is a B&B Molders Flusher 2. I found the installation documentation online and read it carefully. I noted a few things:
- "Vac/Check should be located a minimum of 6" above flood rim of highest fixture connected to waste holding tank." Note: In my trailer, installation is only 4" above toilet rim.
- "Minimum water pressure of 40 psi must be used."
- "Make sure faucet is open completely during entire tank flush cycle. Vac/Check is designed to work at water pressure range of 8–125 psi." Note that this implies that one shouldn't ease the water on, but turn it on rapidly.
- "Water leakage from Vac/Check is likely when water pressure in supply line is under 8 psi."
- "It is normal for a small amount of water to escape Vac/Check as plumbing line for tank flush pressurizes." So mounting the valve in an inaccessible place inside a wall is not an example of competent trailer design.
With this as a starting point, I'm planning to relocate the vac/check valve from its position in the wall to under the valance of the bathroom sink so if/when it leaks the water can go down the shower drain rather than onto the floor. I have done a bunch of inspection and measurement, and it ought to be a simple and manageable modification. Based on floor layouts, it looks as though this would work in all R-Pod models except perhaps the RP-182.
When I actually make the modification, I hope to post photos and results on this forum.