Black Tank Flush Vacuum Breaker Check Valve

[StephenKatSea]

We have a 2008 BH3670RL and it has been fantastic, very few and very minor problems. - But we recently experienced one rather significant situation. Would you please tell me, if the "B&B Molders" Black Tank Flush Vacuum Breaker Valve is working correctly, should we expect any water to ever be discharged from the installed valve? If so, then why did the factory install this device within an interior wall with no way to access the valve? I look forward to your reply on this important topic. We have experienced considerable water/moisture coming from within the wall and apparently originating at that valve. Thanks, Steve

 

[Willym]

The vacuum breaker/check valve is designed to admit air if a vacuum is detected and hence prevent black tank contents being drawn into the supply water system should supply water pressure be lost. It is not designed to discharge water, but I suppose that it could leak. I've been using flush systems for over 8 years now and have yet to see such leakage. Some newer Heartland rigs have access to this valve, usually with a removeable plug in the shower.
I'm sure others will chip in with their experience.

 

[RollingHome]

In the latest issue or post or ??? of the HOC High-lights was a ditty on winterizing our coaches. It listed winterizing something I have never ever winterized on my RV's or ever thought about winterizing - THE BLACK TANK FLUSH SUSTEM, THE SYSTEM THAT HAS THE VAC. BKR. IN IT. I even mentioned to Patti... I've never winterized that, why do it, it's self draining. I am rethinking my logic because I may be wrong. If water is trapped in the line or vac bkr it will burst and leak and do what others seem to have a problem with. One would not know they have a problem until the problem surfaced as yours is now. If you have always winterized your black tank flush you are a step ahead of me... if not perhaps this is your problem. There is another thread just a few days ago with some good suggestions in it. Tomorrow I'll be winterizing my black flush system... Lessons learned.

 

[branson4020]

In the latest issue or post or ??? of the HOC High-lights was a ditty on winterizing our coaches. It listed winterizing something I have never ever winterized on my RV's or ever thought about winterizing - THE BLACK TANK FLUSH SUSTEM, THE SYSTEM THAT HAS THE VAC. BKR. IN IT. I even mentioned to Patti... I've never winterized that, why do it, it's self draining. I am rethinking my logic because I may be wrong. If water is trapped in the line or vac bkr it will burst and leak and do what others seem to have a problem with. One would not know they have a problem until the problem surfaced as yours is now. If you have always winterized your black tank flush you are a step ahead of me... if not perhaps this is your problem. There is another thread just a few days ago with some good suggestions in it. Tomorrow I'll be winterizing my black flush system... Lessons learned.

It's not really the valve that need winterizing, its the line from the UDC to the valve, which can hold water.

 

[RollingHome]

Bob, Please refresh my memory... UDC = ? Also, as you probably have read, several posters have had the same or similiar problem. Do you think the line (freezing) you speak of could be the common source of ALL their problems ? Just a thought.

 

[branson4020]

UDC = Univeral Docking Center, the compartment with the hose connections and winterize and dump valve controls. The hose can hold water if it has a low spot between the valve and the hose connection. But, that said, I just don't see any way for this valve to leak except when you are using the flusher, and then only if its cracked or loose. It's not ever going to leak black water. Its installed well above the level of the black trank.

 

[jimtoo]

I'd almost bet on the flush valve on the toilet is leaking and running under the shroud and floor. The vacuum breaker valve for the tank flusher is only used when you hook up the water to flush the tank and that is the only time it could leak.

 

[StephenKatSea]

I'd almost bet on the flush valve on the toilet is leaking and running under the shroud and floor. The vacuum breaker valve for the tank flusher is only used when you hook up the water to flush the tank and that is the only time it could leak.

Jim - Thanks for your input. I HAD just used the Black Water Flush that afternoon. First thing I did was remove the shroud and check for leaks at the toilet, there were none. I do believe the small ball valve on the "Y" adapter I have placed (and since renewed) at the park's water supply hook-up (this provides water to the black flush line) MAY have not seated well when it was closed upon completion of flushing. If so, would this cause the VBC valve to releave and dump within the wall ? ? i really don't know. OR The ball valve at the "Y" did close, but the Vacuum Break Check valve leaked or failed during the prior afternoon's flushing and the water flowed out onto the floor during the night from within the wall. (For now, this appears most likely) Regardless, mounting the Vacuum Break Check Valve within a wall does not seem desireable. Believe in 2009 and later models Heartland no longer placed the VBC within the wall. . . . . Sorry Jim, think you might have lost this bet. But, I do appreciate your reply and input. BTW, this had nothing to do with winterizing. Not needed . . We're in the Calif/AZ desert and continue to love our BH3670, even with this "odd" leak. - Steve

 

[TedS]

Steve, it may be that the vacuum break valve did leak with the water line still connected at the "Y". It would seem that when the pressure drops when the water is turned sort of 'off' that the vacuum break valve could open, it opens to the outside air, and pee water into the wall space. I guess that it is intended that when tank flush is completed that the water would be disconnected from the input fitting in the UDC when no longer in use. Then the water will back drain out the fitting in the UDC.

 

[StephenKatSea]

I've since been directed to a very useful "wiki" on this topic in our "Owner's Forum", titled "Vacuum Breaker" and "Black Tank flusher block diagram". There is a very interesting "note" in this wiki about the ATOMSHPERIC VACUUM BREAKER/CHECK VALVE (571 Chk). It states that installation of the VBC "must be 6" above flood rim of the highest fixture connected to the wasteholding tank". OK, all seems good there. It then goes on to state, "(ASSE 1001-02; device shall NOT be installed where the venting of water from the device during normal functioning will cause damage.)" Oops . . The installation site selected by the factory (sight unseen within a wall) upon construction of our 2008 BH3670, certainly does NOT comply with this ASSE 1001-02 requirement. Seems like a "heads up" advisement message from the manufacturer to us 08BH owners on this topic would be beneficial.

We purchased our, previously owned, BH in 2010. Perhaps an advisement had been issued prior to our purchase? As I mentioned to Jim, our BH3670 continues to be GREAT, in spite of this unfortunate hidden VBC water discharge and potential damage situation. Hope this helps out other BH owners on our forum. - Steve

 

[ChopperBill]

If our vacuum breaker starts leaking I will just eliminate it with a coupler. Our hose fitting in the UDC doesn't have a check valve and always leaks out water until it drains from the vacuum breaker down to the hose fitting. I may put a check valve there.