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Components of the Black Tank Rinse / Flush System

Jim Beletti

Owner Experience Liaison
Staff member
@Davis Fam

While we don't have a schematic, I can share with you the components used and how they are plumbed.

Here are the 3 components that make up the Black Tank Rinse system:
94231_1-Tank-Flush-ABS-Sprayer-scaled.jpg
  • Top Left item: Plastic Water Inlet Valve – located in Nautilus Panel – manufactured by B&B Molders
  • Top Right item: Atmospheric Vacuum Breaker (AVB) or Back Flow Preventer: located (typically) in bathroom in base vanity cabinet or in/near laundry plumbing area (usually high mounted)
  • Bottom item: Tank Sprayer – located on end wall of black tank(s) near top
We typically use white PEX pipe to plumb this system. So that's white PEX pipe from the back of the Water Inlet Valve, to the input side of the AVB, then from the output side of the ABV to the Tank Sprayer input at the tank. If you have more than 1 black tank, you'll likely have more than 1 of these systems and AVB will likely be co-located.

Hope this helps :)
 

Ray & Dawn Karl

Active member
Any way of getting how the hoses are ran. where T's might be and are there more than 1 AVB on a 2 tank system. Was looking to add a valve to be able to flush one tank at a time.
Thanks
Ray
 

Jim Beletti

Owner Experience Liaison
Staff member
Hi @Ray & Dawn Karl - what Alliance brand and floor plan do you have?

We install the flush system for our black tanks only. If your layout has 2 black tanks, you will have 1 flush inlet port in your Nautilus panel and and two AVBs.

On my Paradigm 340RL, the black tank flush system is plumbed, more or less, like this:

Flush inlet (Nautilus panel) > Atmospheric Vacuum Breaker (behind bathroom sink in vanity cabinet) > a rinse port in side wall of black tank. Exact location of the AVB(s), Black Tanks and Plumbing Routing will vary based on floor plan.

Edit: Corrected above to single flush inlet in Nautilus panel
 
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Ray & Dawn Karl

Active member
Hi @Ray & Dawn Karl - what Alliance brand and floor plan do you have?

We install the flush system for our black tanks only. If your layout has 2 black tanks, you will have 2 separate flush inlet ports in your Nautilus panel and you will have two AVBs.

On my Paradigm 340RL, the black tank flush system is plumbed, more or less, like this:

Flush inlet (Nautilus panel) > Atmospheric Vacuum Breaker (behind bathroom sink in vanity cabinet) > a rinse port in side wall of black tank. Exact location of the AVB(s), Black Tanks and Plumbing Routing will vary based on floor plan.
Ours is the 370FB which has two black and 2 grey tanks. They ran the 2 black tanks on one flush system. I was to looking how they ran it and maybe where the t's are that connected the 2 tanks together. Having two flush inlet in the Nautilus panel would have been great if they ran that way but they didn't. See attach pick of my Nautilus panel and you can see there is only one black tank flush inlet. I was hoping to get the info and see where thing are before taking down the underneath panel.

Ray
 

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Bill Martin

VP, Customer Experience
Staff member
Hi @Ray & Dawn Karl - what Alliance brand and floor plan do you have?

We install the flush system for our black tanks only. If your layout has 2 black tanks, you will have 2 separate flush inlet ports in your Nautilus panel and you will have two AVBs.

On my Paradigm 340RL, the black tank flush system is plumbed, more or less, like this:

Flush inlet (Nautilus panel) > Atmospheric Vacuum Breaker (behind bathroom sink in vanity cabinet) > a rinse port in side wall of black tank. Exact location of the AVB(s), Black Tanks and Plumbing Routing will vary based on floor plan.
To clarify the Nautilus panel will have a single black tank flush connection. If there are dual black tanks on a specific floorplan they are both fed by the same inlet. The T-connection would happen in the underbelly area and will vary by floorplan.
 

Jim Beletti

Owner Experience Liaison
Staff member
Thanks for the update Bill. I've corrected my post to indicate a single flush inlet in the Nautilus.
 

Bulldog2017

New member
Hello
We are new owners of an Alliance Avenue 32rls. I tried black tank flush system for the first time. It leaked and forced water out. Could it be blocked?

Thank
 

Bulldog2017

New member
@Davis Fam

While we don't have a schematic, I can share with you the components used and how they are plumbed.

Here are the 3 components that make up the Black Tank Rinse system:
View attachment 172
  • Top Left item: Plastic Water Inlet Valve – located in Nautilus Panel – manufactured by B&B Molders
  • Top Right item: Atmospheric Vacuum Breaker (AVB) or Back Flow Preventer: located (typically) in bathroom in base vanity cabinet or in/near laundry plumbing area (usually high mounted)
  • Bottom item: Tank Sprayer – located on end wall of black tank(s) near top
We typically use white PEX pipe to plumb this system. So that's white PEX pipe from the back of the Water Inlet Valve, to the input side of the AVB, then from the output side of the ABV to the Tank Sprayer input at the tank. If you have more than 1 black tank, you'll likely have more than 1 of these systems and AVB will likely be co-located.

Hope this helps :)
I called the tech and he told me to replace the Atmospheric Vacuum breaker because the water was being forced back to the outside inlet. I put a new AVB on and the water will still not go to the tank spray. Could the line be blocked? I checked the water one to the AVB and it is clear. Thank you
 

JudyV

New member
I’m in a 2023 Avenue 32RLS and I don’t know where the water went when I tried to use the black tank flush. I tried first with the blank tank open but no water came out anywhere. Tried again later with someone more knowledgeable who opened the grey when no water drained with the black open; still nothing. How can we find out where it’s going and how to correct it?
 

johnda98

Well-known member
What would be great to see are the schematics as well of the fresh, black, and grey tanks for the individual models.
I got one for the 2021 Valor 41-15 .. got it from Jim.. but one for each model posted.. know where to stick ones head after careful incision
 

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Ron C

New member
I’m in a 2023 Avenue 32RLS and I don’t know where the water went when I tried to use the black tank flush. I tried first with the blank tank open but no water came out anywhere. Tried again later with someone more knowledgeable who opened the grey when no water drained with the black open; still nothing. How can we find out where it’s going and how to correct it?
I also have a 23 Avenue 32RLS and could not get any water to flush out of the black tank flush. I tried to turn the different levers thinking that this was the issue but still didn't get any noticeable water to flush out. Does anyone have any experience with this and can guide us who are new to this system?
 

Jim Beletti

Owner Experience Liaison
Staff member
I also have a 23 Avenue 32RLS and could not get any water to flush out of the black tank flush. I tried to turn the different levers thinking that this was the issue but still didn't get any noticeable water to flush out. Does anyone have any experience with this and can guide us who are new to this system?
@Ron C - I suggest you check the Atmospheric Vacuum Breaker (AVB) to see if the in/out lines were hooked up in reverse.

Consider this as a test process:
  1. Locate (likely under the bathroom sink) the AVB
  2. Wrap a bath towel around both lines connected to it
  3. Disconnect the 2 lines from it, noting which line was connected to the inlet side (the bottom I think)
  4. Outside at the Nautilus panel, either connect an air compressor to the black tank flush and send air through it, then check the lines at the AVB location to verify that one (and which one it is) has air coming out, OR, used a water hose and have a helper slowly turn the water on a very small amount and yell out for them to shut it off when water comes out of one of the lines, noting which one
If it turns out the lines were swapped, you'll need to replumb them correctly into the AVB. That may take a couple new fittings and some tools, depending on which AVB we used and how it's plumbed.


Screenshot 2023-10-08 at 5.57.42 PM.png
 
Another trip to the dealer to have them re-plumb the AVB. Seems like something the manufacturer could spend a couple of minutes to make sure the did it correctly. Lacking the attention to detail.
 
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