Which is the black tank pipe and which the gray?As you look at where we hook up the sewer hose and the black and gray pipes come together, the pipe coming in from the left is about 4" wide, the pipe from the right about 2" wide. Logically I would expect the wider from the left to be the black tank, since it's bigger to allow toilet paper, etc. and the gray to be the smaller. Is this correct?

You are correct. The 4" is black and the 2" is grey

That's what I thought. Just caught that I think it was done wrong at the factory and thought to be fair I'd double check. Today as a test I put some dish soap in the commode, drained the black and nothing came out. Then I let the gray out and everything came out suds (the gray had been completely drained, I winterized earlier). this is the 3rd thing that has been wrong that seems a bit unusual on our trailer. It's not only that the pipes are wrong but it's all stickered wrong, too.

Since they are both empty now, were it mine, just to be absolutely sure before I began demanding redress from the dealer, I would put three or four gallons of water in one or the other and check again, then do the other one. Maybe there is a cross connect or something equally silly.

Can you get down under the trailer and see where the pipes go?

Today I drained both until nothing came out, closed both. Then I put dish soap and water into the commode. Opened the black nothing came out. Opened the gray and got water and bubbles. I'll be nice when I call but this will be the third really screwed up thing (one of which was dangerous) on this new trailer. I'm beginning to wonder if it was a bad day at the factory whenever ours was made. I did look and there aren't any pipes I can see coming into either one. But one sits right under the shower and one right uner the commode -- where they sit would be backwards from how they're labelled as well thought my question stemmed from the bubble test not from the placement of the tanks.Thank you

which should be the black /sewage & which the grey tank?

joebedford
Nomad II
Jan 08, 2014
3.0charlie wrote:
To me, the result is what I would expect since the black tank only holds the liquids / solids from the toilet. Every other drain (sinks and shower) all go the gray tank... so if you drained dish suds from the kitchen sink, it would be normal to have no liquids from the black tank, and all from the gray tank.

Unless the 'commode' you are talking about is the bathroom toilet, then yes they really screwed up at the factory...
I hope you're not washing your dishes in the commode!
PawPaw_n_Gram
Explorer
Jan 08, 2014
Glad they fixed it.

The wrong plumbing connections from the tanks is a pretty big deal.

It isn't something a dealer can do on his own in a couple hours. He has to take photos and convince the factory to send the necessary parts and pay for the repairs.

The dealer is likely more unhappy with the problems with the unit than you are.
travel4family
Explorer
Jan 08, 2014
Just thought I'd update this. We had several warranty items fixed in late October / early November before we put it up for the winter. The tanks were plumbed backward from the factory and have now been redone. Should make things a lot easier next season!
69_Avion
Explorer
Oct 31, 2013
I would prefer 2" for the gray water tank outlet instead of 1-1/2", and 3" is normal for the RV black water tank outlets. The issue is what is the outlet on the black water tank? Did they use a reducer to get it down to 2" or will a new outlet, or new tank need to be installed?
RV-1_2n-FUN
Explorer
Oct 31, 2013
DesertFiver wrote:
Just re-label the pulls... problem solved! :)

First off, when did the RV industry go to 2" and 4"? Standards have been 1 1/2" gray and 3" black.

Second, re-labeling is not fine. Black is 3" for flushing of solids. A 1 1/2" or 2" would not be adequate for a black tank.
DesertFiver
Explorer
Oct 30, 2013
Just re-label the pulls... problem solved! :)
anconn
Explorer
Oct 22, 2013
69 Avion wrote:
A lot of black tanks will only have a 3" pipe. You definitely don't want to be under a 3" for the black tank. 2" pipe is plenty for the gray water tank.

The Black pipe is 3" and the grey is 1 1/2".

If you are the first owner I would go back to the dealer with the problem. You will have to prove it to him by showing where the toilet goes in and the small line comes out but......He better do something about it.
69_Avion
Explorer
Oct 22, 2013
A lot of black tanks will only have a 3" pipe. You definitely don't want to be under a 3" for the black tank. 2" pipe is plenty for the gray water tank.
travel4family
Explorer
Oct 22, 2013
Brand new last year, we are the first owner.
jrwitt
Explorer
Oct 21, 2013
Hank MI wrote:
The black tank will run under the 'commode' so that it dumps directly into it, no plumbing. Not enough water to flush the toilet through plumbing to get to the tank.

Some RVs have a 2nd toilet in a half-bath. The toilet still drains into the black tank. This is not unusual in larger (40 foot+) Class A DPs. Don't know how they solve the water flow issue.

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which should be the black /sewage & which the grey tank?

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