Water Leak From Black Box Under Bathroom Sink

[taxrew]

My 5h Wheel 2018 Cougar 310rls, bathroom sink has two white hoses going to a black box type item that has some kind of white Foam/Fabric (?) in it. The two hoses are in addition to the hot and cold water hoses that connect to the faucet.

I fixed the leak by using plumbers tape on the two white hoses that I reconnected to the black box.

What is the function of this item and where are the hoses coming and going to?
Before I pull the walls in the storage to trace the hoses, I better understand the function????

Thanks

[chuckster57]

That is the black tank rinser back flow preventer. Very common for the cheap plastic ones to leak. You can replace it with another plastic one, it may or may not last. There shouldn’t be any foam inside it, I would replace it with a quality brass one.

[Skippy38]

Here is what I did for mine:

https://www.youtube.com/watch?v=urywWdM6TrA

[dutchmensport]

On a different forum, which I don't use any more, some time ago, I suggested just replacing the black tank anti-syphon valve under the sink with a simple L connection, like shown in the video above. I got scorned to death on that one. All kinds of criticism from everyone saying how unsafe and unsanitary that was, how awful it was, how I was putting my health at risk and my family, how threatening that was to the campground as it could contaminate the campground water system, and on and on and on. I was flabbergasted. I eventually stopped using that site because of such harsh criticism, not because of exclusively on this subject, but many more.

Now, a few years later on this forum, it's suggested over and over again to simply replace the anti-syphon valve with the simple L-connection, and to use a check valve in-line or even at the water source, but even that's not really an issue any more.

Maybe folks wised up, or maybe that was just a mean spirited group of people back then who were so germa-phobic they weren't good for the own needs.

At the time, mine actually clogged up and blocked. The price of a simple plastic one at my dealership was around $45 for a replacement and I felt that was horrible. So, I just used the L PVC pipe and kept on camping and never posted on that site again on this subject.

For what it's worth, the L PVC pipe worked just fine. I never had issues and I most certainly did not "die" because of doing this, nor did anyone else.

When I traded that trailer for another one, I pointed it out to my salesman on the trade, and he said that didn't matter one way or the other (on the resale value of the trade).

My next travel trailer and my next fifth wheel had the same black tank plastic anti-syphon valve on them, and they never gave me any problems, ever.

[sourdough]

Originally Posted by dutchmensport

On a different forum, which I don't use any more, some time ago, I suggested just replacing the black tank anti-syphon valve under the sink with a simple L connection, like shown in the video above. I got scorned to death on that one. All kinds of criticism from everyone saying how unsafe and unsanitary that was, how awful it was, how I was putting my health at risk and my family, how threatening that was to the campground as it could contaminate the campground water system, and on and on and on. I was flabbergasted. I eventually stopped using that site because of such harsh criticism, not because of exclusively on this subject, but many more.

Now, a few years later on this forum, it's suggested over and over again to simply replace the anti-syphon valve with the simple L-connection, and to use a check valve in-line or even at the water source, but even that's not really an issue any more.

Maybe folks wised up, or maybe that was just a mean spirited group of people back then who were so germa-phobic they weren't good for the own needs.

At the time, mine actually clogged up and blocked. The price of a simple plastic one at my dealership was around $45 for a replacement and I felt that was horrible. So, I just used the L PVC pipe and kept on camping and never posted on that site again on this subject.

For what it's worth, the L PVC pipe worked just fine. I never had issues and I most certainly did not "die" because of doing this, nor did anyone else.

When I traded that trailer for another one, I pointed it out to my salesman on the trade, and he said that didn't matter one way or the other (on the resale value of the trade).

My next travel trailer and my next fifth wheel had the same black tank plastic anti-syphon valve on them, and they never gave me any problems, ever.

In the last 5-6 years I've performed the above repair, had it done at a dealership and watched it done on a friend's RV by a mobile tech. It was apparently the "accepted" method used by both the dealership and the mobile tech. Like you, there are some forums I just don't bother with due to a seemingly hostile environment - got better things to do.

One thing mentioned quite often when making the above mod is to then put a screw on anti siphon valve on the end of the hose since the one inside was removed. I think the possibility of the contents being sucked back into the water supply, over the 2' high "hump", is remote but I do that just in case.

[Skippy38]

Originally Posted by dutchmensport

On a different forum, which I don't use any more, some time ago, I suggested just replacing the black tank anti-syphon valve under the sink with a simple L connection, like shown in the video above. I got scorned to death on that one. All kinds of criticism from everyone saying how unsafe and unsanitary that was, how awful it was, how I was putting my health at risk and my family, how threatening that was to the campground as it could contaminate the campground water system, and on and on and on. I was flabbergasted. I eventually stopped using that site because of such harsh criticism, not because of exclusively on this subject, but many more.

Now, a few years later on this forum, it's suggested over and over again to simply replace the anti-syphon valve with the simple L-connection, and to use a check valve in-line or even at the water source, but even that's not really an issue any more.

Maybe folks wised up, or maybe that was just a mean spirited group of people back then who were so germa-phobic they weren't good for the own needs.

At the time, mine actually clogged up and blocked. The price of a simple plastic one at my dealership was around $45 for a replacement and I felt that was horrible. So, I just used the L PVC pipe and kept on camping and never posted on that site again on this subject.

For what it's worth, the L PVC pipe worked just fine. I never had issues and I most certainly did not "die" because of doing this, nor did anyone else.

When I traded that trailer for another one, I pointed it out to my salesman on the trade, and he said that didn't matter one way or the other (on the resale value of the trade).

My next travel trailer and my next fifth wheel had the same black tank plastic anti-syphon valve on them, and they never gave me any problems, ever.

I did this video a little over a year ago when I replaced my valve. I posted it on a number of Facebook RV groups. I, like you, got called everything from a saint to a child murderer and everything in between lol. I have learned to take it all in stride though, open another bottle of wine and enjoy the sunsets from my nice, leak free 5th wheel lol

[Getn off]

Originally Posted by dutchmensport

On a different forum, which I don't use any more, some time ago, I suggested just replacing the black tank anti-syphon valve under the sink with a simple L connection, like shown in the video above. I got scorned to death on that one. All kinds of criticism from everyone saying how unsafe and unsanitary that was, how awful it was, how I was putting my health at risk and my family, how threatening that was to the campground as it could contaminate the campground water system, and on and on and on. I was flabbergasted. I eventually stopped using that site because of such harsh criticism, not because of exclusively on this subject, but many more.

Now, a few years later on this forum, it's suggested over and over again to simply replace the anti-syphon valve with the simple L-connection, and to use a check valve in-line or even at the water source, but even that's not really an issue any more.

Maybe folks wised up, or maybe that was just a mean spirited group of people back then who were so germa-phobic they weren't good for the own needs.

At the time, mine actually clogged up and blocked. The price of a simple plastic one at my dealership was around $45 for a replacement and I felt that was horrible. So, I just used the L PVC pipe and kept on camping and never posted on that site again on this subject.

For what it's worth, the L PVC pipe worked just fine. I never had issues and I most certainly did not "die" because of doing this, nor did anyone else.

When I traded that trailer for another one, I pointed it out to my salesman on the trade, and he said that didn't matter one way or the other (on the resale value of the trade).

My next travel trailer and my next fifth wheel had the same black tank plastic anti-syphon valve on them, and they never gave me any problems, ever.

Wasn’t by chance the heartland owners group was it? They are an interesting bunch, and I rarely go on there because of it.
Troy

[taxrew]

Thanks to all for the knowledge and suggestions. Does the failed valve also cause a sewer odor coming from my hot and cold faucets?

[wiredgeorge]

I used to frequent another RV forum and there was so much unsafe and plain STUPID stuff said and promoted I felt it best to leave them to themselves as I got tired of trying to correct stupid. Don't go anymore; worst stupid was folks answering "can I tow such and such a camper with my teeny tiny truck (or SUV)" . No point in being frustrated. Some forums are just not as quality as this one.

[flybouy]

Originally Posted by taxrew

Thanks to all for the knowledge and suggestions. Does the failed valve also cause a sewer odor coming from my hot and cold faucets?

No, odor from the fresh or city water means a dirty potable water system. It's typically more noticable from the hot water side. You need to drain the water heater, put the system in winterizing mode and flush the system out with a bleach solution followed by freash water.