Bathroom sink drains to the black tank? That was a surprise!

[wmb]

This week while in an electric-only site we managed to back up our black tank for the first time. We were not using the toilet that much so we weren't watching the level very closely. We were using the bathroom sink quite a bit, though, and I was under the impression that that sink goes to the gray tank. Indeed, that's the way the diagram in the manual represents the system.

After we dumped and flushed I ran the bathroom faucet for a few minutes and sure enough the black level rose while the gray level stayed steady.

Is it normal for the bathroom sink to drain to the black tank?

[polarlyse]

I don't know if it 's usual or not but I've heard of it being plumbed either way. I'm not sure just where mine goes either. Might be I should check on it one of these days.

[rowiebowie]

Watching this with interest. First reaction is, shouldn't happen. Yet your experience says otherwise.

If plumbed that way, it's a very messy accident waiting to happen.

[LBOskiBear]

I believe my 19' drained into the black tank. However, it's not clear to me if it does so in my 27'.

I'd prefer it - the black tank usually takes a lot longer to fill and it would be a nice feature to divert some water that would otherwise go into the gray tank

[vintagemotor]

All of the Internationals I have laid hands on bath sink drains to black, 23' and 28' FB and RB. Not sure about the rest.

[Cyclist]

Our 28 definitely drains into the black tank.

[rmkrum]

The putative reason is that draining the Lav sink into the black tank assures enough water in the black tank to help keep solids suspended and to supply enough water to flush it out more thoroughly. It helps avoid the "mountain of brown" directly under the toilet...

Not all AS models and years do this. IIRC, my 2007 International CCD does not...it would be difficult to plumb it that way given the wet bath layout.

[uncle_bob]

Hi

The owners manual pretty clearly shows which why it *should* be plumed. Some models are done one way, other models are done the other way. I suspect it's as much a matter of the trailer layout / gray tank location as anything else. You can *always* hit the black tank from the bathroom sink.

Bob

[sheriff1]

2014 30’ Flying Cloud bathroom sink drains to black water tank.

[A W Warn]

Originally Posted by wmb

This week while in an electric-only site we managed to back up our black tank for the first time. We were not using the toilet that much so we weren't watching the level very closely. We were using the bathroom sink quite a bit, though, and I was under the impression that that sink goes to the gray tank. Indeed, that's the way the diagram in the manual represents the system.

After we dumped and flushed I ran the bathroom faucet for a few minutes and sure enough the black level rose while the gray level stayed steady.

Is it normal for the bathroom sink to drain to the black tank?

Yes it is normal, for some trailers.
The drawing in the Owners Manual is a misrepresentation, a generic drawing.
To get the actual construction drawing of your specific trailer you must use the Parts Manual, which for your trailer does show the lavatory waste water going into the black tank.
Look at page 470 of 545 (or page IV-13)
You might want to download this.
https://www.airstream.com/wp-content...gcloud2014.pdf

[Wayne&Sam]

Yup, in our 2014 25' FC Rear bedroom the sink drains to the black tank.

I like that arrangement as our black tan never fills before the grey. At times, to extend the grey tank, we'll use the bathroom sink instead of the kitchen sink.

It also ensures plenty of water in the black tank so it drains well.

[pcskier]

Originally Posted by A W Warn

Yes it is normal, for some trailers.
The drawing in the Owners Manual is a misrepresentation, a generic drawing.
To get the actual construction drawing of your specific trailer you must use the Parts Manual, which for your trailer does show the lavatory waste water going into the black tank.
Look at page 470 of 545 (or page IV-13)
You might want to download this.
https://www.airstream.com/wp-content...gcloud2014.pdf

Weird. I have a 2014 23d and downloaded the parts manual you linked to (thanks). Page 470 shows a 'parts list' for a "25' Twin". The next page shows a diagram of the plumbing for "Drain System, Above Floor, 30'". Then there are no other diagrams for any of the other lengths. Is it just me that it downloaded this way?

[zapper]

Originally Posted by wmb

This week while in an electric-only site we managed to back up our black tank for the first time. We were not using the toilet that much so we weren't watching the level very closely. We were using the bathroom sink quite a bit, though, and I was under the impression that that sink goes to the gray tank. Indeed, that's the way the diagram in the manual represents the system.

After we dumped and flushed I ran the bathroom faucet for a few minutes and sure enough the black level rose while the gray level stayed steady.

Is it normal for the bathroom sink to drain to the black tank?

Apparently, this connection varies from AS model to model/yr. This is the norm. For example our 2007 25' Safari bathroom sink drained to the grey water tank, which is what one would expect. However our 2017 30' FC like your 25' FC drains to the blackwater tank. This for most people is counter intuitive. I found our the hard way with a spill from the bathroom sink onto the floor. Glad to hear that you observed this drainage anomaly before a spill occurred.

However, before my spill, I did read in my manual that my bathroom sink drains to the greywater tank. Apparently this was a typo. Later, after the spill, I looked at the plumbing diagram which shows the bathroom sink drains to the blackwater. Go figure.

Please, be aware that there are those on this forum who may blame you for not reading the owner's manual from cover to cover, and will steadfastly not assign any blame to AS for designing a drainage system that could potentially provide a health hazard to those who were caught unawares. Don't pay them any attention.

So the message I got from others was when one buys an AS one has to read all the text and look and understand all the wiring and pluming diagrams to fully understand the complexities of owning an AS, otherwise you shouldn't buy it. Annoying.

.

[A W Warn]

Originally Posted by pcskier

Weird. I have a 2014 23d and downloaded the parts manual you linked to (thanks). Page 470 shows a 'parts list' for a "25' Twin". The next page shows a diagram of the plumbing for "Drain System, Above Floor, 30'". Then there are no other diagrams for any of the other lengths. Is it just me that it downloaded this way?

I do not know for sure, but (I assume) the drawing in the Owners Manual is the generally correct drawing. (Again, my assumption).

Generally, I have found (again my assumption based on what I see) that the prior year drawing is used is for the following year unless a modification is needed to adapt for some change. If needed the drawing is then either new from scratch or the prior drawing is modified, marked with an addendum, then reissued/published.

I'll check my 25' in the driveway, and report back. (34' is 700 miles away, so no checking it today)

[A W Warn]

So, I learned a few things:

My 25's lavatory sink does not drain into the black tank. I poured a gallon of water in the lavatory sink, it came out of the grey drain.
There is no drawing of the waste piping in either the Owners Manual or the Parts Manual, (I know I've seen one somewhere???)

The Owner's Manual For my 34' has a schematic drawing that shows the waste water from a "washer" going into the black tank. Since there is no washer, and a lavatory sink is not shown, I have to assume that washer is the lavatory sink.

The drawing also shows 1.25" waste pipe carrying both the galley sink and shower. I can't believe Airstream cheaped out on the pipe for that!!!! It should have been 1.5". Hope I never have to repair any of that pipe, because fittings would be impossible to find.

[zapper]

"So, I learned a few things:"

I fail to understand why the learning experience with a AS has to be so difficult? All this misdirection could have been avoided during a model change by AS preparing a proper set of "as-builts" and text during the QC process and have them included in the owner's manual.

[pcskier]

Originally Posted by A W Warn

I do not know for sure, but (I assume) the drawing in the Owners Manual is the generally correct drawing. (Again, my assumption).

What I meant was, there is a drawing for a 30' trailer's layout, but none of the other lengths. I am pretty sure some drain to black and some to grey, but you'd think the parts manual would have a layout for each length, not just for the 30. If there was just one plumbing layout for all lengths, you'd think the drawing would state its for all trailers not just the 30.

[A W Warn]

Originally Posted by A W Warn

<<snip>>
There is no drawing of the waste piping in either the Owners Manual or the Parts Manual, (I know I've seen one somewhere???) <<snip>>

Update:
I went out to my 25' trailer and pulled out the hard copy (note book) Owners Manual. It does have drawings of the complete waste water system. The drawing is dated a few years earlier than the 2000 year model, that was built in 1999. I knew I had seen the drawing.

The online manual at Airstream's website does not include these. I suspect that is because the paper drawing were two sided in the manual. I'm guessing, whoever scanned into a new format miss some drawings.

[rmkrum]

Originally Posted by zapper

"So, I learned a few things:"

I fail to understand why the learning experience with a AS has to be so difficult? All this misdirection could have been avoided during a model change by AS preparing a proper set of "as-builts" and text during the QC process and have them included in the owner's manual.

A sad truth of any unregulated manufacturing process is that there is NEVER enough budget to properly document it as you go, and NO reason to properly document it once the built item goes out the factory door.

Thor is not building airplanes--otherwise the drawings would be mandatory, and required to be accurate by law.

[jbknowso]

A w warn,
Can you point me to an owners manual for my 69 Sovereign?
My small booklet manual is not as detailed as the one you linked to a FC
Happy 4th!

Jbknowso