black tank flush question

[dryfly]

There seems to be a lot of post reporting issues with the black tank flush system. Leaks, broken vacuum breakers, etc.

I'm assuming the flush is nothing more than a spay nozzle inside the tank, and I'm wondering if it really does any more to clean the tank than just filling the tank with fresh water and draining, or maybe filling tank a quarter full 2 or 3 times and draining.

On my previous 5th wheel my black tank flush got stopped up after about 6 uses, so I just got used to rinsing the tank. Doing this and using one of the fittings that go on the drain outlet that allows back flushing has worked well for me. I just carried this habit over the the Reflection and have avoided the use of the flush system.

[trailrydr]

Not sure if this is true or not, but IMO, the flush works like the old black tank wands I used to use on the end of a garden hose and stuck down the RV toilet to flush with. The only difference is that now I can hook up to the Nautilus black tank connection and use the internal sprayer built into the tank which probably does a better job than trying to spray it manually when you cant really see into the tank.

As for the issues with the breakers and suchdue to pressure, my owners manual states the folliwing:

"Sewer Tank Flusher
The sewer tank flusher is designed to rinse the interior of the
black tank. A separate water hookup is located in the docking
station. Flush the tank after dumping by:
1. Connecting the sewer hose and attaching a garden hose –
not your fresh water hose – to the sewer tank inlet (see
photo).
2. Open the water supply to full pressure to flush tank.
3. When the water runs clear from the sewer hose, shut off
the water supply and disconnect the garden hose from the
water source. Do not disconnect hose from flush inlet until
water has drained from system.
Do not leave any hose connected when not in use and do not
add any check valves to this system"


To me, this means dont restrict the water flow when using the flush system. And thats what we do and never had any issues doing it. We also close the valve when doing it and let run a few minutes, then release the contents. Again, no issues. But, all of this assuming one has 80lbs or less of normal city water head pressure on the line while doing it.

Note: Probably would be worth keeping under 50lbs just to be on the safe side.

[dryfly]

I'm not saying anyone should not use the black tank flush. It's a great addition to the trailer. I'm just wondering if it does any better job of keeping the tank clean than just filling an emptying the tank with fresh water (and maybe avoiding some of the mentioned issues)??

I've used the "Geo System" for treating my sewer tank for several years, and have found it to totally prevent odors. I'm thinking it also helps me keep my black tank pretty clean.

[NB Canada]

The black tank rinse actually does almost nothing

After I rinse with it and the water runs clear I used a toilet wand and all kinds of stuff came out

[Rabbit]

I use the black tank flush, but agree it doesn’t do much as I believe the spray is weak. Too much like a lawn sprinkler, not strong like a toilet spray nozzle. I’ve found mine works best if the hose does not go through the pressure regulator, and no other water is being drawn while the flusher is running. I still use the “down the toilet” nozzle a couple of times each season, and alway before winterizing.

[Jayhawk8586]

So a newbie question. Just purchased a 351 - there is only one black water line exiting toyhauler. However, I have toilets in the master bedroom and in the garage of the toyhauler. I'm assuming both deposit into the same black holding tank. Can anyone confirm that for me. Thanks from the new guy

[FT4NOW]

So a newbie question. Just purchased a 351 - there is only one black water line exiting toyhauler. However, I have toilets in the master bedroom and in the garage of the toyhauler. I'm assuming both deposit into the same black holding tank. Can anyone confirm that for me. Thanks from the new guy

The garage bath should have its own sewer hose connection behind the rear tire as well as the dump handle. The black flush should be around there as well.

[Hoopy Frood]

What year 351? We have the 2019 351M and it has the second drain behind the rear wheel.

[Riverbug]

I never had a black flush until this trailer. I always used the fill and dump and wand through the toilet method. I always thought that it was clean because the water ran clear after a bit. After using the black flush the first time, I was amazed at how much more "crap" kept coming out. I tried the old methods just to see if there was something different about the design of the new tank or something. But nope, when I used the black flush after the other methods I was able to get more out. So, I'd take the black flush over the old methods any day. Maybe it's just the design of my model, not sure, but it certainly makes a difference. I do still use the method of closing the valve and letting it fill about 1/2 to 2/3 using the black flush then open the valve all the while with the water still running until it come clean. I do not use a pressure regulator on the flush like I do for the city water inlet, so it does come out pretty strong. But so far no issues with leaks; I keep an eye on it though. One thing that helps during the fill process is to use the One Command phone app so I can stand by the dump valve and see when the water gets to 1/3 and 2/3 to open the valve before it gets too full and risk a very bad situation. Sorry for rambling...

[Jayhawk8586]

Hmmmm. My 351 is a 23. I'm only seeing a black tank line in front of the axles and a gray tank line behind the axles. Both open/close valves are behind the axle toward the back of the rig. Appreciate all the help on this rather dark topic. All the cleaning tips very helpful for a newbie.