22RBS Black Tank Back Flow/Anti Siphon Location

BigTexRex · 03-19-2018, 08:18 PM

Does anyone know the location of the back flow/anti siphon valve for the black tank flush on a 22RBS?

busterbrown · 03-19-2018, 09:57 PM

If your floor plan is the Cougar 22RBS, my "guess" is that it may be in one of two places:

1. It may be located next to the driver side of the bed, underneath the "night stand" accessible by a removable panel.

2. Or underneath the bathroom sink, maybe behind a removable panel. My Bullet's backflow valve is located here.

These would be my guesses.

**sourdough** · 03-20-2018, 06:21 AM

I would look under the sink, maybe behind a panel (mine is).

Is your black tank/water connection toward the rear on the driver's side? It might be behind the shower. That's where my neighbor's was a week or so ago when he tried to fix his on his Bighorn. Couldn't reach it so he and the mobile RV tech cut the pipes off under the wall (5th wheel).

BigTexRex · 03-20-2018, 04:23 PM

Thanks, guys. I found it tucked up behind the bathroom sink.

Steveo57 · 03-20-2018, 05:38 PM

I've seen the air admittance valve under the bathroom sink. There's also one under the kitchen sink. But I didn't notice the backflow valve. But now that you mention it I remember seeing a few extra lines running up under the sink and wondering why they were there. I didn't crawl in there far enough to see what they were hooked up to. I'll take a peak tomorrow.

Check that air admittance valve is screwed in tight. Mine was barely screwed in a few turns.

Thanks for the info.

Sent from my Nexus 6P using Tapatalk

Pmedic4 · 03-21-2018, 02:07 AM

While we have a fifthwheel, ours was under the bathroom sink. Found out when it failed as we'd hooked up to rinse, and water started pouring out from the bathroom vanity.

BTW, went to the local RV dealer, and they wanted $75 for the part, ordered from Walmart for $36. They do fail.

BigTexRex · 03-21-2018, 05:08 PM

Quote:

Originally Posted by Steveo57

I've seen the air admittance valve under the bathroom sink. There's also one under the kitchen sink. But I didn't notice the backflow valve. But now that you mention it I remember seeing a few extra lines running up under the sink and wondering why they were there. I didn't crawl in there far enough to see what they were hooked up to. I'll take a peak tomorrow.

Check that air admittance valve is screwed in tight. Mine was barely screwed in a few turns.

Thanks for the info.

Sent from my Nexus 6P using Tapatalk

Thanks...yes, both were barely on the pipes.

BigTexRex · 03-21-2018, 05:14 PM

Quote:

Originally Posted by Pmedic4

While we have a fifthwheel, ours was under the bathroom sink. Found out when it failed as we'd hooked up to rinse, and water started pouring out from the bathroom vanity.

BTW, went to the local RV dealer, and they wanted $75 for the part, ordered from Walmart for $36. They do fail.

I had one RV were it was installed backwards...water everywhere. I will replace the OEM with this one from Watts: https://www.supplyhouse.com/Watts-07...aker-Lead-Free

chartrand · 03-22-2018, 03:28 PM

Quote:

Originally Posted by BigTexRex

Does anyone know the location of the back flow/anti siphon valve for the black tank flush on a 22RBS?

I have the same unit, glade you found it! I was not sure where it was either but as I sit here typing this, I’m looking at it.

Out of curiosity... why were you trying to find it?

Sent from my iPhone using Tapatalk Pro

Steveo57 · 03-22-2018, 03:47 PM

Quote:

Originally Posted by chartrand

I have the same unit, glade you found it! I was not sure where it was either but as I sit here typing this, I’m looking at it.

Out of curiosity... why were you trying to find it?

Sent from my iPhone using Tapatalk Pro

They have a habit of leaking when flushing the black tank. Some people replace them with a better quality one.

Sent from my Nexus 6P using Tapatalk

chartrand · 03-22-2018, 04:18 PM

Quote:

Originally Posted by Steveo57

They have a habit of leaking when flushing the black tank. Some people replace them with a better quality one.

Sent from my Nexus 6P using Tapatalk

I’d be interested in what you replace yours with if you do replace it.

Sent from my iPhone using Tapatalk Pro

BigTexRex · 03-22-2018, 05:19 PM

Quote:

Originally Posted by chartrand

I have the same unit, glade you found it! I was not sure where it was either but as I sit here typing this, I’m looking at it.

Out of curiosity... why were you trying to find it?

Sent from my iPhone using Tapatalk Pro

I've had two bad experiences with them on other RVs so I replace it with a Watts LF288A as soon as I can. The first experience, it was installed backwards and leaked several gallons before I noticed. The second time it just leaked.

ChuckS · 03-23-2018, 10:10 AM

I have never used my black tank built in flush. I installed clear backflush with gate valve and clean my tanks that way. I can see when they are clean and I don’t have to worry about anti siphon valves.

Sent from my iPhone using Tapatalk

Steveo57 · 03-28-2018, 01:51 PM

It's tucked up under the bathroom sink good. I haven't had a chance to flush my black tank yet to check it out.

I'm considering just removing it and using a backflow preventer on the hose connection at the docking station. Thats how my last camper was setup with an aftermarket flush system. I don't really see any downside to pulling it out. The only time you're hooked up to the connection is when you're flushing the tank and it's going to be empty then.

I guess if you were flushing the tank and you had the outlet closed and the tank level was covering the tank flush connection and you lost pressure in the flushing water line then you could suck something into the flush hose supply. Those are a lot of what ifs and a backflow preventer on the hose connection would serve to prevent that anyways from what I can see.

Am I missing something?

Click image for larger version

Name: IMG_20180321_142140.jpg
Views: 225
Size: 72.7 KB
ID: 15798

Sent from my Nexus 6P using Tapatalk

Emptynesters · 04-06-2018, 03:08 PM

Are these on all RV's? I have a flush for the black tank that is on the side of my trailer that I put a hose on to clean the black tank. This is my first trailer and am looking for an ed-u-ma-k-shen??? LOL

**chuckster57** · 04-06-2018, 03:21 PM

Any RV that has a factory installed black tank rinser will have an anti siphon valve. It’s location isn’t always the same, I’ve seen them under the bathroom sink, behind the shower wall, even in a cabinet with lots of other fresh water lines.

They are there to insure the fresh water system your hooked up to doesn’t get contaminated. As long as there is an anti siphon device between the black tank and the rinse water source, your good.

Auggie Waterman · 05-09-2018, 07:28 AM

I must not be understanding anything here even after re-reading... OK, there's two black flush connections on the passenger side of our fifth wheel (Hideout 308bhds) toward the front. One for each black tank, has 1.5 bathrooms.

I thought a black flush would connnect to a spray nozzle of some sort inside the black tank connected to the toilet, simple. Why would there be a "anti siphon" or backflow preventer or any connection to the other clean water supplies or lines in the trailer??!

BigTexRex · 05-09-2018, 11:58 AM

Quote:

Originally Posted by Auggie Waterman

I must not be understanding anything here even after re-reading... OK, there's two black flush connections on the passenger side of our fifth wheel (Hideout 308bhds) toward the front. One for each black tank, has 1.5 bathrooms.

I thought a black flush would connnect to a spray nozzle of some sort inside the black tank connected to the toilet, simple. Why would there be a "anti siphon" or backflow preventer or any connection to the other clean water supplies or lines in the trailer??!

The anti-siphon is to prevent a possible back flow into the fresh water system you're using to flush the black tank. You're right, the lines do not interconnect with any other fresh water lines in your RV.

You may also like: