Holding tanks

[RandandDoug]

Bought a used 2019 Keystone Avalanche 321RS.
All company specs I have seen show it having 1 black and 1 grey tank.
There are two grey Pulls and one black. The salesman and I did a fairly quick walkthrough, my 3rd rv, and he explained that there are 2 grey tanks, and the that was that.
I am out today familiarizing myself with the trailer, flushing tanks and stuff, and it seems as though the bathroom sink is plumbed into the black tank, not sure about the shower yet, will be going back out to run some water through that too.
Is anyone here familiar with that? Seems strange to me, but I can live with it. Just curious and all the places to call are of course closed for the weekend.
Thanks

[mileshuff]

RickLight wrote:

mileshuff wrote:
So they are not all plumbed together? I too have three tanks in similar configuration as yours (1 grey rear of trailer, 1 grey, 1 black near front) but they are all plumbed to a single dump connection in the center of the trailer.

You got luck, or smart. What rig?

I have a 2014 Winnebago Lite Five 26FWRKS. Best trailer I've ever owned.

[BarneyS]

mileshuff wrote:


So they are not all plumbed together? I too have three tanks in similar configuration as yours (1 grey rear of trailer, 1 grey, 1 black near front) but they are all plumbed to a single dump connection in the center of the trailer.

Not at all uncommon. Mine is the same way except reversed. Black & grey at rear and another grey at the front. All to one dump valve. The 3" and 4" are joined just before the dump valve.
Barney

[RickLight]

mileshuff wrote:
So they are not all plumbed together? I too have three tanks in similar configuration as yours (1 grey rear of trailer, 1 grey, 1 black near front) but they are all plumbed to a single dump connection in the center of the trailer.

You got luck, or smart. What rig?

[mileshuff]

Fisher Bill wrote:
We have a rear kitchen so it has it's own grey tank with the other up front for the shower/bathroom sink. So 3 tanks to dump when it comes time and I have to pull forward about 15' to get to the third.

So they are not all plumbed together? I too have three tanks in similar configuration as yours (1 grey rear of trailer, 1 grey, 1 black near front) but they are all plumbed to a single dump connection in the center of the trailer.

[mileshuff]

My Winnebago 5th wheel has two greys. We have a rear kitchen with the shower/bath sink on other end of the trailer. The handle for the kitchen tank is near the rear of the trailer while the handles for the other grey and black tanks are together near hose connections and main drain.

[RickLight]

Fisher Bill wrote:
We have a rear kitchen so it has it's own grey tank with the other up front for the shower/bathroom sink. So 3 tanks to dump when it comes time and I have to pull forward about 15' to get to the third.

This and 3 short hoses does it 90% of the time for me.

[Fisher_Bill]

We have a rear kitchen so it has it's own grey tank with the other up front for the shower/bathroom sink. So 3 tanks to dump when it comes time and I have to pull forward about 15' to get to the third.

[larry_cad]

RandandDoug wrote:
I will be under it tomorrow, so maybe I will get some more surprises, but that's what's fun about this stuff, sometimes!! Haha

Given the topic, why does this NOT conjure up my idea of fun???

😄

[time2roll]

All normal and ordinary as described above.

[RickLight]

I think it's not so much different levels as the distance between drains.

The general rule is 1/4" drop per 12" run. If the drains are too far apart then they can't connect to the same outlet. Mine are about 20' apart, so 5" drop!

[Roger10378]

When the bathroom and galley are on different levels they will have separate gray tanks. If they didn't it would be easy to overfill the tank and it would leak out of the one on the lower level while you didn't realize it and keep using the one in the upper level.

[RandandDoug]

Thanks for the responses. The labels at the pulls were wrong. Not sure why or how, but now I know so no problem. Not sure if it came like that or might have had some work done on it. And it does have two greys, but all the generic manuals and things online say one. I will be under it tomorrow, so maybe I will get some more surprises, but that's what's fun about this stuff, sometimes!! Haha

[ssthrd]

agesilaus wrote:
Dump some dye and water down the drains one at a time and see which valve shows the color

Good idea. Two different colors of food dye.

I forgot to say that both the shower and the bathroom sink go into the grey tank.

[TXiceman]

work2much wrote:
Pretty common for 5th wheels to have 2 grey tanks. One for the bath and one for the galley.

Not all common to have two gray tanks, but some do. It is usually when the kitchen sink and shower are on opposite ends. The bathroom sink may be routed to the black tank since it is generally low use and the black needs lots of water to operate properly.

Ken