Black Tank Sprayer Leaking

[lolocamper]

When we dump our black tank, and hook up the hose to the built in sprayer and turn it on, we get water coming our by the tires. Looks like its from inside the fender well and may be leaking from inside. Anyone else having this problem? We have a 2015 North Trail 24BHS

 

[mlpeloquin]

Never on our fifth wheel, but the hose for the black water flush popped off on our Class C. Talk about a lot of water and mud! I had to crall under and reattach it. You need to run the black water flush after the pressure regulator. I also use a back flow (check) valve in the black tank flush line. Too much pressure is what caused the problem on our old Class C. If you are flushing your tank without a pressure regulator, then it may have caused a connection to come loose enough to leak. Time to open up the coroplast and look. I hope you are using a pressure regulator for your fresh water as well or the same could start happening to your fresh water lines as well.

 

[sengli]

Sounds like the anti siphon valve is either not connected correctly or is not working right. Search this topic, there are alot of people here myself included, who have had major leak issues with these in line valves in the black tank spray lines failing. I finally removed mine and the extra PEX water line runs and no more leaks ever again from this issue.

 

[Bob&Patty]

X2 on what Mark said. Did it once and had water running out the door. Never hook up a water hose to your RV without a GOOD regulator.

 

[JohnDar]

There isn't a whole lot of rocket science in that anti-siphon valve, either. It's made of plastic, with a plastic float that gets pushed into the closed position when the water flows. Trouble is, the stem for the float can and will stick partially up and water comes over the plunger and out the top. And upon examination, I don't see any kind of gaskets to ensure a seal when the plunger is pushed up. Couple that with the plastic fittings that you can't tighten behind a closed-in wall and it's just a matter of time...

 

[chrisj]

Thanks for posting what the black adapter is. Thought it was some sort of pressure regulator. I've successfully used the black tank flush in the past but just went to use it and water came pouring out from under the bathroom sink and out the fender like lolocamper. I have a pressure regulator on the incoming hose so I don't think that's the issue. Is there a way to "reset" it? Should I just remove it or is it important to keep the anti-siphon device in place to keep black water from flowing out the hose?
2013 North Trail 32 BUDS.

 

[Gary521]

Just bypass it. Put a check valve behind the inlet and you are good to go.

 

[Rollin_Free]

Yep happened to me but I'm probably responsible for the issue. While I always use a regular on the supply water I didn't see a reason to have one on the black water flush. It really sounded like it was cleaning super good until of course the water started leaking like yours. It was the vacuum breaker that had the output port split however when I tried to disconnect the PEX I couldn't get it off until I used a pair of pliers ironically on the port that was split.

So mine is located behind the shower wall in the same area as the shower lines and not to hard to get at but I got scratched all over both hands trying to get it out. I finally realized if I removed the access hole cover I could get in there without too much trouble. I initially just put in an in-line check valve, as was already mentioned, in place of the vacuum break but later reinstalled a new one and also replaced the shower faucet and shower head.

 

[chrisj]

Thanks Gary521. That sounds like the best plan. I'm done with the anti-siphon device.

 

[Bones]

I don't understand why the Anti Siphon device is giving so many campers issues. Is it really that important that it has to be in there? Is the application of the device being used incorrectly and why is it being placed in such an impossible area of the campers.

 

[Rollin_Free]

What's really amazing is I have been searching on-line for the actual reason for the atmospheric vent that is installed on the Black Water Flush line and so far I haven't been able to locate anything that specifically addresses this question. What I did find is that all used water storage tanks must be vented to maintain the same pressure in the tanks as the outside environment. However when a Black Water Flush system is installed I'm thinking the outside vent is eliminated from the roof and this device is placed inside the RV. There is a requirement for it to be installed a minimum of 6" above the highest fixture in the RV. That height is usually the lavatory in the front of a 5th wheel where the shower, toilet, and lavatory are located. This black water atmospheric vent maintains the same air pressure inside the tank as the "inside the RV" and is also there to prevent back siphoning into the water system.

I'm going to continue to look for the reason why the atmospheric vent is used on the black water flush line instead of a check valve. Until I find the real answer I'm not going to consider converting the black water flush system line to a check valve.

 

[Bones]

What's really amazing is I have been searching on-line for the actual reason for the atmospheric vent that is installed on the Black Water Flush line and so far I haven't been able to locate anything that specifically addresses this question. What I did find is that all used water storage tanks must be vented to maintain the same pressure in the tanks as the outside environment. However when a Black Water Flush system is installed I'm thinking the outside vent is eliminated from the roof and this device is placed inside the RV. There is a requirement for it to be installed a minimum of 6" above the highest fixture in the RV. That height is usually the lavatory in the front of a 5th wheel where the shower, toilet, and lavatory are located. This black water atmospheric vent maintains the same air pressure inside the tank as the "inside the RV" and is also there to prevent back siphoning into the water system.

I'm going to continue to look for the reason why the atmospheric vent is used on the black water flush line instead of a check valve. Until I find the real answer I'm not going to consider converting the black water flush system line to a check valve.

The anti siphon is used specifically for reducing the effect of the black tank siphoning from the potable water supply. The black tanks are vented through the roof. If you have a potable water supply hooked up to the sprayer line and the black tank creates a vacuum the anti-siphon valve prevents the sprayer from sucking water from the potable water supply. Instead it sucks air. When you supply pressure from the input side if forces a valve closed to push water through. It also acts like a back flow protection because of this valve but the over pressure more than likely will go into the interior of the camper. In the directions for the anti siphon valve it states not to place it where it can cause damage because it can expel water from the valve. Yet we all have this little valve that causes a lot of damage when it does not work right. Since a suitable location for these valves has not been determined maybe having a specific spot accessible and sealed off with a drain to the outside should be used so that our campers are not destroyed by this valve and people are not bypassing the actual intent of them. When people see water coming from this drain location they know the valve has gone up and needs to be replaced. Instead they are having their campers flooded for no reason and are unfortunately forced to eliminate the valve which has good intentions but not executed well.

- - - Updated - - -

On further thought a check valve will prevent an over-pressure of the line which would be back pressure but will not prevent a siphoning effect of the line.

 

[Rollin_Free]

What you stated sense to me and knowing the black water is vented outside helps understand. I agree that there needs to be an isolated location to put the anti-siphon device and a way to route the water out of the trailer to prevent water damage inside.

 

[JohnDar]

Mine did have a drain. Down the wall cavity and onto the floor inside the rig, soaking the bottom of the steps. If I hadn't relocated the converter from it's original position underneath it, I'd have really been screwed. When I pulled it out from underneath (no access port for it), it was missing the top cap. I've replaced it with a Sharkbite check valve located on the ceiling level of the basement. There is also a check valve I installed at the UDC inlet since the check B&B Plastic inlet there broke a few years ago. And it only looked like a flow reducer, not a check valve.

I am cognizant of how my plumbing system works on this rig and the likelihood of the tank siphoning through both check valves is highly remote.

 

[danemayer]

The anti siphon is used specifically for reducing the effect of the black tank siphoning from the potable water supply. The black tanks are vented through the roof. If you have a potable water supply hooked up to the sprayer line and the black tank creates a vacuum the anti-siphon valve prevents the sprayer from sucking water from the potable water supply. Instead it sucks air.

I think I need a little further explanation of this idea of the black tank flush siphoning potable water.

If you hook a hose to the black tank flush with the water supply turned on, water flows into the black tank. If you turn the water off, no water can flow and I don't see what there would be to siphon, other than a small amount of water in the hose.

What am I missing?

 

[Bones]

I think I need a little further explanation of this idea of the black tank flush siphoning potable water.

If you hook a hose to the black tank flush with the water supply turned on, water flows into the black tank. If you turn the water off, no water can flow and I don't see what there would be to siphon, other than a small amount of water in the hose.

What am I missing?

Dan Your not missing a thing. It is someone thinking of a remote possibility of something happening or somehow some one did something stupid and you end up with a regulation or recommendation of adding a component that when based in reality does nothing more than create more problems than the intention of the device but I will offer the only real thought That I can come up with................. Nothing. This is a device to combat the idea of cross contamination from blackish water to potable water and allows for a mechanical separation of the two by allowing an air gap to exist. This is my theory. I am not sure if my theory is correct or not but is the best thought I can put together from reading a few articles about how the device works. I was not in the sitting room of the persons who sat down and put together the RVIA guide lines for RV's but I would be greatly interested in asking them what the theory behind the regulation was.

Bones

 

[danemayer]

I'm not sure, but I thought the idea was that if pressure dropped at the faucet while flushing the black tank, and water was sucked backward, that the suction could possibly pull some black water from the spray head if the tank was full. Even though it's unlikely, since the consequences could be severe, I think the anti-siphon valve is used to prevent contamination of the park water supply.

 

[LBR]

I'm not sure, but I thought the idea was that if pressure dropped at the faucet while flushing the black tank, and water was sucked backward, that the suction could possibly pull some black water from the spray head if the tank was full. Even though it's unlikely, since the consequences could be severe, I think the anti-siphon valve is used to prevent contamination of the park water supply.

This is the correct analysis of backflow principles and it takes several "ifs" to align at the same exact time for a backflow event to even happen....highly unlikely, but possible, so therefore our world is full of testable and non-testable assemblies and devices.

 

[SNOKING]

The valve is there for one purpose, to prevent liquid from the black water tank from siphoning out the inlet. With the UDC the inlet is higher than the tank and a simple inlet with check valve will prevent that. Now to find it and it's plumbing on our BH3575el?

Early on with our 2005 SOB I had water run on the floor the first time I used it. The valve was located behind a panel in the computer desk of all places!!!!!

Chris

$1.99 valve(black part) in a rig that cost 10's of thousand of dollars.

 

[Rollin_Free]

Mine did have a drain. Down the wall cavity and onto the floor inside the rig, soaking the bottom of the steps. If I hadn't relocated the converter from it's original position underneath it, I'd have really been screwed. When I pulled it out from underneath (no access port for it), it was missing the top cap. I've replaced it with a Sharkbite check valve located on the ceiling level of the basement. There is also a check valve I installed at the UDC inlet since the check B&B Plastic inlet there broke a few years ago. And it only looked like a flow reducer, not a check valve.

I am cognizant of how my plumbing system works on this rig and the likelihood of the tank siphoning through both check valves is highly remote.

OK, so you know I meant a planned path for water to exit the trailer if the valve fails. As an example in the second level bathroom of my house I put a, cool whip container with a hose connected to the bottom, under the bathtub drain and routed the small hose down inside the wall to the basement. I have another container at the basement end of the hose so if I ever have another leak in the upstairs bathtub drain I'll know about before it damages anything.