Black Tank Vacuum Breaker Check Valve

We have a 2008 BH3670. The black tank has a "flush out" line. The supply hose for the flush system appears to run from the backside of the UDC, across the "maze" of wires & hoses in the basement, then up into a hole, aft and to the "door-side" of the large WC stool pvc dishcharge line, it then re-appears out of the same hole and runs down and connects to the side of the black tank. I am told there is a "Vacuum Breaker Check Valve" within this "flush out line". Is the VBC valve within the wall, at the rear of the stool and forward of the salon electrical panel? If so, how do you access that "VBC" valve? If the black tank is pressurized (such as by a flush out line inadvertently left slightly cracked open - allowing the black tank to fill to its max), could this cause the "VBC" valve to activate and dump water within the wall?

That seems to be the case for us. We awoke to find a substantial amount of water at the base of the carpeted steps leading to the bedroom/bath area. After removing all contents and the panels of the basement, no obvious leaks were noted on the water lines within the basement. All water was accumulated at the base of the support framing in the aft basement area and also within the bottom of the aft kitchen counter and within the void space behind the electrical breaker & fuse panels.

How can you get to this "VBC" valve and vertical run of the black tank flush line without cutting into the wall?

Look forward to any input on this topic. Thanks, Steve

The black tank is vented, so it can fill (even overfill to the point that it comes bubbling out of the toilet) but it cannot pressurize. In any case, the vacuum breaker does not work to alleviate pressure in the tank, and cannot discharge anything onto the floor, unless its just broken and leaking. It's there to prevent any possibilty of creating a siphon through the black tank flush system and back out the supply hose. I have no idea how you would access it if it is in the wall behind the commode.

Ours is behind the access cover for the faucet plumbing in the shower. Unscrew the access cover and there it is.

Your's is similar to the way mine is installed. It is NOT behind the access hole in the shower stall. Try grabbing the lines that lead to it and PULL. It's just stuffed up there, between the wall studs.

JohnDar said:

Your's is similar to the way mine is installed. It is NOT behind the access hole in the shower stall. Try grabbing the lines that lead to it and PULL. It's just stuffed up there, between the wall studs.

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John - I did try PULLING on the 2 plastic hoses, but they didn't seem to budge. I feared that the "questionable" crimp fittings on the plastic water lines were likely to give way. Any idea how far up into the wall the valve may be located. Really can't imagine what the manufacture was thinking when they placed it within a wall with no way to get at it. Curious if "Heartland" had any thoughts about how to access this VERY poorly located valve. Thanks to all for the replies. - Steve

If you pull it hard enough it will come out its just plastic. The pex fittings screw on to it, you won't pull them off. Mine was by the shower access hole. I took it out and got rid of it. The rince works a lot better now.

Steve, Heartland puts them up there because of code regs. I suppose they might have thought of a better way to remove it, like nipples on the supply and flush lines but I guess that could open up the possibility of leaks.
If there is a cabinet on the wall above the commode, it shoould be easy to remove it for a view of the valve. You may even be able to reach it. Some have also accessed it via the closet by the front door. Hmm, maybe a place to put a removable access panel?

I agree its a lousy design. I see you have a 2008 coach. In my 2009 it was moved to behind the shower access panel. Anyway, maybe its time for a reset here. The vacuum breaker, if its busted or loose, will only leak when you are using the black tank flusher. After rereading your original post, that doesn't sound like your symptoms.

Steve, is it possible the water came from a water line leak and not from the black tank flush line?

TedS said:

Steve, is it possible the water came from a water line leak and not from the black tank flush line?

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I really thought I was going to find an obvious "water line leak" within the basement area. But, there was no leaks on the lines seen in the basement. Water/moisture was located at the base of the support framing and floor cleats in the aft of the basement - predominately on the "door side". Water was also on the vinyl floor in the forward kitchen and step-up to the bath/bedroom. After removing the breaker and fuse panels, water was found on the floor within the cabinent behind those panels. These areas are directly below where the black tank flush lines apparently connect to the vacuum breaker check valve within the wall on our 2008 BH.

Have the same setup as you do and had a similar water problem. Never could get the existing valve pulled out so just cut the tube and installed a bronze check valve instead. Old valve is still living happily behind the wall and cabinets/garage have been dry for over a year now.

Lance & Jo said:

Have the same setup as you do and had a similar water problem. Never could get the existing valve pulled out so just cut the tube and installed a bronze check valve instead. Old valve is still living happily behind the wall and cabinets/garage have been dry for over a year now.

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Lance - That's sounds like a very good and common sense solution. Is vertical height of the new check valve a concern? Or is it just a "one way" in line check valve. I was able to remove the "unused" factory installed generator start mini & hr meter from the electrical panel. This enabled me to look thru the hole and see the wall behind the electrical switch/monitor panel. I could see an approx. 6" dia. factory cut hole in the wall, thru which the wires pass from the wall interior and attach to the back of the switch/monitor panel. No water lines or vacuum breaker check valves were apparent. So, I must believe that valve and connections are in the wall below that "wire way" 6" hole. Thanks again for your good input, Steve

Here is a link to Heartland Owners Wiki entry for your backflush system. Info on the vacuum breaker included.

I used an in line bronze valve from a local plumbimg store and mounted it on the back of the UDC for best support. Hope this helps.

When the UDC connection for the black tank flusher broke on mine, I replaced it with a brass city water connection than comes with a real check valve in it. The plastic B&B Molders thing on there was just a hollow tube, like a flow restrictor, not a check valve. If I ever have a problem with the anti-siphon valve in the wall, I might relocate it to behind the shower stall access port. Or just leave it off completely.

My black tank flusher quit working last month and I've finally gotten around to working on it. My BH is an '06 and I knew the lines went up behind the commode cuz I could hear the rushing water through the entryway panel whenever I flushed. Instead of cutting into the panel, I removed the housing for the fire extinguisher. That allowed access to the lines. I started pulling on the 2 lines but couldn't make a lot of progress. After more looking, I discovered that the lines were 'secured' by a small piece of carpet that was stapled to the edge of the interior cabinet. I cut through the carpet with a pocket knife and was able to pull the 2 lines down. Apparently, Heartland has switched hardware. My valve was made by Swan Industries Inc. , on the left in the pic

This is what was going into BC's on the line last June. At least they were putting them near the shower access port.

JohnDar said:

This is what was going into BC's on the line last June. At least they were putting them near the shower access port.

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That's what I have.

TANDT said:

That's what I have.

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I probably have the same, but I know for a fact it's nowhere near the shower access port.

JohnDar said:

This is what was going into BC's on the line last June. At least they were putting them near the shower access port.

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All, While inspecting the plumbing behind the basement wall, I discovered the rectangular plastic "cap" from this check valve, sitting on top of the water heater! The tabs that hold it in place appeared to be broken, and the cap has been sitting in this location probably since build date, as there was caked sawdust in it. Do we need to figure out how to get to it in the wall and see if it was replaced or if we need to fix?

Erika