2016 Passport Ultralite 2770. Maiden voyage was this past weekend. Everything worked but 2 items. 1. Found out if you leave the bathroom door open, it blocks the intake vent for the furnace and apparently the furnace somehow overheats and when it shuts down, takes several hours to start back. Couldnt for the life of me figure out what was going on, thought maybe the tstat was messed up, but once we kept the bathroom door closed, unit worked perfectly the rest of the weekend.2. And this one is what this thread is about. Decided to dump and flush the blackwater tank there at the campground before we left since they had full hookups and i knew i wouldnt be holding anyone up while i flushed the tanks clean USING THE BUILT IN FLUSH SYSTEM. As per the picture attached, the hose comes from the outdoor fitting into the bathroom under the sink. It turns up and goes thru some sort of vent thingy (i have no idea what this is and this is the part that is leaking) then goes out and down to the black tank. Just what the heck is this thing, (i'm assuming its some sort of vent altho i cant figure why it would be needed.) And surely its not supposed to be leaking out the TOP of it. The screw on fittings are tight, and the fittings themselves are not leaking. Its spraying out from under the top of the square plastic vent looking thing. I'm tempted to just do away with this and install a 90 degree fitting there so it goes straight down to the black tank, but would like to know if its needed, and if its not supposed to be leaking (which its not), then i'll call the dealer i bought it from and get them to send me a new one.

That is the world famous 'anti-siphon vacuum breaker' that RV MFG. is required to install so contaminated water can not back flow into potable water system.They are junk...........better style ones are available Now for a basic course.Connection for flusher is in side of RV and above top of black tankConnection has a 'check valve' inside that fitting (just like city water connection)Line goes from connection up several feet to the anti-siphon deviceLine then goes back down several feet to black tankFlush nozzle is in side at top of black tank SOooooooooooBlack tank has to get completely full then yucky water could be forced thru nozzle and up thru line to anti-siphon device then back down thru line to connection then thru the check valve and into hose in order to possibly contaminate potable water supply.Guess if you had a poop fountain blowing out black tank roof vent yucky water could get into flush line and down to connection and then check valve be stuck open and hose still connected and potable water supply was down some of that yucky water could get into system.Possibility YES-------probability Pretty LOWJust saying...not recommending cause I've been accused of using common sense vs following 'standards'

so are you saying i should find a better quality one, or i could do what i was talking about and just do away with it. Chances of me EVER having black water get THAT far back up the system are slim and none.

And when the tank is full and you drive around it fills the flush line. If the line filled it could siphon out from the tank. Use the anti siphon valve. It lets air in to brake a vacuum but doesn't let water out, if it ain't broken. If you can't flush it out, warranty it or buy a new one.

I had a problem with my aeroater leaking also. Turns out the hose going into the black tank was kinked thus putting to much back pressure in line and waer went out top of aerator. Once hose was un-kinked, worked fine . Just do no use alot of pressure in hose.

It is required so you don't contaminate the RV park water system.

black water clean out connection leaks | Good Sam Community

OldRacer
Explorer
Feb 12, 2016
evanvalk wrote:
Others have told me they had a leak problem only if they turned the hose on while the black tank cap was locked on.
yea, i tried it both ways, with the valve close and open. Leaked both times.

Problem is solved now.
evanvalk
Explorer
Feb 12, 2016
Others have told me they had a leak problem only if they turned the hose on while the black tank cap was locked on.
Old-Biscuit
Explorer III
Feb 11, 2016
hohenwald48 wrote:
I think I will. I tried our flush connection once and it leaked so I just stopped using it. I'm not too fanatical about tank cleaning anyway. I just flush the toilet with a reasonable amount of water when it's used and I haven't had a problem in over 25 years (10 of them full time) of owning an RV.

My father in law is one of those who flushed his black tank with the valve closed, got distracted and about a thousand gallons later had a real mess inside.

Same here....they are just holding tanks
Fill them dump them......done
hohenwald48
Explorer
Feb 11, 2016
I think I will. I tried our flush connection once and it leaked so I just stopped using it. I'm not too fanatical about tank cleaning anyway. I just flush the toilet with a reasonable amount of water when it's used and I haven't had a problem in over 25 years (10 of them full time) of owning an RV.

My father in law is one of those who flushed his black tank with the valve closed, got distracted and about a thousand gallons later had a real mess inside.
Old-Biscuit
Explorer III
Feb 11, 2016
hohenwald48 wrote:
Will it leak fresh water from the hose or dirty water from the tank?

Looks to me like it will leak a bit of dirty water from those holes marked "air inlet" in the drawing. Maybe even more than a little if it's below the level of the holding tank and gets a siphon action started via those "air inlets".

It will leak clean water from the section of flush system right at the connection 'check valve' which is part of the hookup......spitz then nothing

The air holes break any vacuum that would allow siphoning IF the check valve in the connection doesn't close. Remember the flush line goes to a open nozzle that won't suck anything from the black tank unless tank was FULL FULL FULL, check valve stuck open and vacuum breaker air holes were plugged---------and then where is it going to go with water supply hose bib closed (if it was open water pressure would push water into system not allow if back out)

Really is a lot of woo--ha (much ado about nothing)

For $5 pick one up and give it a try
hohenwald48
Explorer
Feb 10, 2016
Will it leak fresh water from the hose or dirty water from the tank?

Looks to me like it will leak a bit of dirty water from those holes marked "air inlet" in the drawing. Maybe even more than a little if it's below the level of the holding tank and gets a siphon action started via those "air inlets".
Old-Biscuit
Explorer III
Feb 10, 2016
hohenwald48 wrote:
I think I see what you mean. I wonder why the manufacturers wouldn't just do that in the first place? Seems it would be cheaper than the valve they install under the cabinet.

Because of 'code'---'standards' RV MFG. must meet.

Anti-siphon vacuum breaker required in potable water/contaminated water connections.
The current device used is not suppose to leak when properly functioning

The hose end vacuum breaker WILL leak each time water supply is secured.......by design
OldRacer
Explorer
Feb 10, 2016
Yep, that part was a whopping $5 from Ace Hardware.
hohenwald48
Explorer
Feb 10, 2016
I think I see what you mean. I wonder why the manufacturers wouldn't just do that in the first place? Seems it would be cheaper than the valve they install under the cabinet.
OldRacer
Explorer
Feb 10, 2016
Yep, works exactly the same.

The male threaded end screws into the port on the exterior of the RV leaving the female side of the bib to screw the hose into, which is the correct way for flow and it keeps anything from coming out of rv into garden hose.

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