First Trip & Grey Water Issue

[bike_addict]

Originally Posted by w7ts

Looking at your PDF, I see no way any more water than what's in the shower drain trap (or perhaps more of the shower drain plumbing if some of it is sloping the wrong way) could end up in the shower unless the tip of the pipe into the tank from the shower drain (11M) was below the surface of the water in the tank. That brings up another entirely different possible cause. Keep in mind that I am only trying to explore the possibilities. I am not suggesting that you have any option other than to follow their path of trying to fix the problem.

Ken

This has me puzzled If I were a member of the top 1% , I would buy you a new trailer and tear the one you have apart to solve the puzzle.

THAT SOUNDS LIKE FUN!!! That would be a great science experiment.

Honestly I don't understand the physics behind it. But we would dump a full sink and run additional water through the sink for one reason or another and end result the sink would appear to be draining fine but the shower pan would have water in it halfway up to the lip. I am not sure how much water could be in the shower drain pan or associated piping but it seemed like a lot in the shower.

And I need to get this resolved because I am not getting any work done. Spending too much time on this forum and the internet trying to figure out what's going on.

And while typing this I got a call from the AS tech that's been working with my dealer and had a good conversation with him. Same story, the vent for the system can't handle the amount of water that the system can flow through. Fix is to slow that water down. But he also was not aware of all of the details so I went over the whole story with him. He seemed kind of puzzled as well that so much water was in my shower, he was expecting just what would be in the P trap, not a half full shower. He is going to have the dealer check to make sure the auto-vent in the shower is working and not sticking.

So still I'm not sure how much confidence I have in this completely fixing the problem. Hopefully this patch will do the job. And I guess whether I like it or not, finding out the hard way looks to be the only way...

[bike_addict]

Originally Posted by w7ts

It would be any interesting experiment to have a whole bunch of people with newer trailers fill their sinks and drain them while watching the shower floor.

I need to get Traildog to try it. He has the same trailer I do, '12 Flying Cloud 25FB.

If he's not reading this I'll get him to try it at the Piney Woods Rally in two weeks.

[Goal15]

Originally Posted by w7ts

I think that if this has never happened to you, then you don't need to do anything.

It would be any interesting experiment to have a whole bunch of people with newer trailers fill their sinks and drain them while watching the shower floor.

Ken:

See post #48. This isn't the first time grey water backing up in the shower has been discussed on the Forums.... so it makes me wonder if they are now suggesting Hepvo that it might answer the problem for some other folks as well. Guess I will have to see what the plumbing schematic for my AS looks like.

Dana

[Goal15]

Ronnie

we can all dump water down are galley sinks and then sit around and commiserate as we wait for it to drain out of our shower pans.

Dana

[bike_addict]

Originally Posted by Goal15

Ronnie

we can all dump water down are galley sinks and then sit around and commiserate as we wait for it to drain out of our shower pans.

Dana

Yep, add that to the games list. The "Sink-to-Shower Drain Race".

[Ag&Au]

Originally Posted by Goal15

Ken:

See post #48. This isn't the first time grey water backing up in the shower has been discussed on the Forums.... so it makes me wonder if they are now suggesting Hepvo that it might answer the problem for some other folks as well. Guess I will have to see what the plumbing schematic for my AS looks like.

Dana

OK, now I do remember reading that. I wonder if your shower drain plug will cause the holding tank to explode.

I think we all need a ferret with a helmet cam.

I tried that once at home, but he came up in the neighbor's tub.

[Traildog]

Originally Posted by bike_addict

I need to get Traildog to try it. He has the same trailer I do, '12 Flying Cloud 25FB.

If he's not reading this I'll get him to try it at the Piney Woods Rally in two weeks.

I'm reading this thread with great interest right now and will definitely want to do the test at the Piney Woods Rally in a couple of weeks. That will be my next opportunity to check it out.

I don't like hearing about flaws like this, when I have enough on my plate just learning about all the stuff that does work. BTW, everyone, I just picked up my 2012 25' FC (just like bike_addicts') a week and a half ago. We did not fill up the sink during our two night stay, we just hand washed our dishes and let them air dry. Now I am eager to enter the "Sink-to-Shower Drain Race" at the rally. Sounds like I may have a winner, which in this case would be a bad thang.

Bike_addict, it is unfortunate that it has taken so long to diagnose and fix this problem, causing a cancellation of your weekend plans! Nice weather this weekend around here...

[Mr & Mrs S]

Bike_Addict,

Man hopefully they get you fixed up. I know its frustrating dealing with a dealership. I hate it when they give you the run arounds. Sounds like your staying on their case. Hopefully they will have you fixed up good for the Texas Piney Woods Rally. When I went up there yesterday to visit it sure was great weather. Made me want to go home and hook up the AS and head on up there and hang out. Weather was GREAT!....Ok Ok Im done rubbing it in.

Really,I hope they get you fixed up. Keep us up to date!

[Jack46]

This has been an interesting thread for me. We purchased our 2011 FC 30' this February. It took a while for us to figure out through the process of "elimination" that our grey and black release valves were mislabeled. AS sent us a new set of labels, but our monitor seems never read contents accurately. And now the face plate has partially separated from its base. I appreciate the tip that an owner is able to calibrate the monitor.

In any event we are making to making the trek to the dealer in a couple weeks. Jack

[sinjin]

Hmmm, just another data point. We experienced something similar when the singuy washes the dishes. When I wash the dishes I always drain the sink a little when it gets about 3/4 full, don't like to slosh, heh. When he does the dishes he just lets it get full to within an inch of the top if that's what it takes to finish the job. We have ended up with water in the shower a couple of times when the singuy did his fill'r'up wash and drain even though we were still in the green fill zone on the gauge. We were connected to full hook-ups both times and just opened the grey tank valve. Also noted that the drain time was shorter than normal for a "full" tank.

Just yesterday I let the sink get >3/4 full before draining completely and noticed that it drained slower than normal. I wonder if this is a "feature" of airstream design, hee.

For the record book, we have a 2009, 28ft International.

sinjin

[bike_addict]

Originally Posted by jsmith84

Bike_Addict,

Man hopefully they get you fixed up. I know its frustrating dealing with a dealership. I hate it when they give you the run arounds. Sounds like your staying on their case. Hopefully they will have you fixed up good for the Texas Piney Woods Rally. When I went up there yesterday to visit it sure was great weather. Made me want to go home and hook up the AS and head on up there and hang out. Weather was GREAT!....Ok Ok Im done rubbing it in.

Really,I hope they get you fixed up. Keep us up to date!

Thanks for that. Appreciate the wonderful visual of what we're missing. I better have a functional trailer this week.

[Fly at Night]

Been reading this saga with interest too. One starts to wonder, why does one trailer have such a problem and others don't? I have a Flying Cloud too, only it is two feet longer and two years older than bike addict's.

I have had absolutely no problem with my systems' monitor or grey water draining into the shower stall.

I hope your problem is resolved asap and you can get back to really enjoying your trailer.

[Gene]

I don't know if this will help—from Wikipedia:

"Air admittance valves (AAVs or Durgo valves) are negative pressure-activated, one-way mechanical vents, used in a plumbing system to eliminate the need for conventional pipe venting and roof penetrations. A discharge of wastewater causes the AAV to open, releasing the vacuum and allowing air to enter plumbing vent pipe for proper drainage. Since AAVs will only function under negative pressure situations they are not suitable for all venting applications, such as venting a sump, where positive pressures are created when the sump fills. Using AAVs can significantly reduce the amount of venting materials needed in a plumbing system, increase plumbing labor efficiency, allow greater flexibility in the layout of plumbing fixtures, and reduce long-term roof maintenance problems associated with conventional vent stack roofing penetrations.
While some state and local building departments prohibit AAVs, the International Residential and International Plumbing Codes allow it to be used in place of a vent-through-the-roof. AAV's are certified to reliably open and close a minimum of 500,000 times, (approximately 30 years of use) with no emanation of sewer gas; and some manufacturers claim their units are tested for up to 1.5 million cycles, or at least 80 years of use. Air Admittance Valves have been effectively used in Europe for more than two decades. US manufacturers offer warranties that range from 20 years to lifetime."

These were developed in Europe years ago and have appeared in the US in the past 10 years. Perhaps the one closest to the shower or grey tank is not getting sufficient air flow and has failed. Airstream has a habit of buying the cheapest parts they can find and the part may be bad. They usually work quite well.

But the Wikipedia article mentions they do not work on sumps because positive pressure builds in the sump. It seems to me the grey tank is like a sump and this may be the problem. In this case the vent pipe to air should be close to or on the tank and ideally should also connect directly to the shower drain, preferably just above the connection from the kitchen drain. The sinks drain fine, but pressure in the tank is causing water to back into the shower, but I can't visualize how that can happen. While water is much heavier than air, the weight of the water and the gravity flow in the system is not enough to overcome air pressure in this system. The schematic does not show enough information and I am not a plumber, so I may have this all wrong. The exact location of the pipes may reveal the answer. Perhaps the drain from the sinks joins the shower drain just above the tank and water flows into the shower before it can get to the tank.

The AAV's should help the system when the vent pipe is not close to the sinks so additional vent pipes are not needed on them. When plumbing fixtures are all located close together as in a house, one or two vents can work for a whole house, but when the bathrooms and kitchen are dispersed through the building, you may see many vent pipes on the roof unless AAV's have been installed in some areas. But in a closed system, all is different.

We haven't had this problem and I've never noticed AAV's in our trailer—maybe because I haven't looked for them or they may be hidden somewhere. Perhaps someone at Airstream read about AAV's and thought this would be an improvement; perhaps they thought they could reduce the use of pipes this way and didn't know enough to do it right; perhaps they bought cheap stuff.

Gene

[Ag&Au]

Originally Posted by Fly at Night

Been reading this saga with interest too. One starts to wonder, why does one trailer have such a problem and others don't? I have a Flying Cloud too, only it is two feet longer and two years older than bike addict's.

I have had absolutely no problem with my systems' monitor or grey water draining into the shower stall.

I hope your problem is resolved asap and you can get back to really enjoying your trailer.

I think some of it has to do with how you use the sink. If you don't dump a full sink of water at once, it probably won't happen. If you leave the gray water tank drain valve open when hooked up, it probably won't happen even with a full sink.

It is not been determined if all recent Airstream models are plumbed this way.

It has not been determined what the real cause is. I am convinced the the tail pipe draining into the gray tank has to be way too long for it force as much water as is being reported.

As far as the monitor system is concerned:

There have been a lot of attempts to design a accurate reliable holding tank monitor. However I've never seen one I felt I could trust. there are too many variables. You can calibrate it and it will probably be OK for a while. It is best to use it for a general indication. If you want to check the black tank, shine a flashlight down the toilet. For the gray tank the only sure to to know its empty is to empty it. The best full indication is standing water on the shower floor.

Ken

[Gene]

The monitor is only a suggestion of what might be, or might not. The sensor in each tank gets dirty and doesn't seem to work right, the wires are just telephone wire and the contacts get dirty and don't work right, and possibly the electronics in the monitor aren't designed very well. After a while, experience tells us what is in each tank.

A black tank in our trailer won't get full in a week (unless we get cholera and so far we haven't had that problem) and that's with dumping dish water in the toilet when we are boondocking. If we are very careful, we won't use all the fresh water in 4 days, but showers will significantly shorten that time to 2 days. Same for grey tank. We sometimes bring a 5 gallon container of fresh water, but don't seem to ever use it. Your results may vary.

Ken has a good point about whether recent Airstreams have all been plumbed the same way. If all 25' FB's are the same and only some people are having problems, that may indicate faulty AAV's or that Airstream is experimenting with some of them.

Gene

[bike_addict]

Well I'm still waiting. The part didn't arrive at the dealer today so really hoping it shows tomorrow.

[Silver Goose]

Originally Posted by w7ts

I think that if this has never happened to you, then you don't need to do anything.

It would be any interesting experiment to have a whole bunch of people with newer trailers fill their sinks and drain them while watching the shower floor.

Bike_Addict, I can't believe this is still going on and can understand your frustration! Until this thread developed the facts, I was one who assumed the tank was vented directly. This has been educational.

As for the experiment, add an 08 27FB to the list. It has never happened to me, but I don't recall ever dumping a full sink into the closed tank. I tried, and I got a small geyser in the shower! It acted like the rush of water in the drain compressed air in the drain pipe forcing water to shoot up from the shower drain followed by a release of air, then it repeated one more time, by then the sink was empty. My GW tank was empty at the time which may account for the odd but different results from what Bike_Addict is experiencing. Or dimensional differences may come into play, there may be something different with our air admittance valves, or a yet discovered restriction in his drain pipe. Since I typically use RV parks, my gray tank dump valve is often left open to the slinky. That would provide an alternative vent for the tank and would explain why I and possibly others hadn't observed this phenomenon before.

I do hope they get you fixed soon.

[dznf0g]

Originally Posted by w7ts

I think some of it has to do with how you use the sink. If you don't dump a full sink of water at once, it probably won't happen. If you leave the gray water tank drain valve open when hooked up, it probably won't happen even with a full sink.

It is not been determined if all recent Airstream models are plumbed this way.

It has not been determined what the real cause is. I am convinced the the tail pipe draining into the gray tank has to be way too long for it force as much water as is being reported.

As far as the monitor system is concerned:

There have been a lot of attempts to design a accurate reliable holding tank monitor. However I've never seen one I felt I could trust. there are too many variables. You can calibrate it and it will probably be OK for a while. It is best to use it for a general indication. If you want to check the black tank, shine a flashlight down the toilet. For the gray tank the only sure to to know its empty is to empty it. The best full indication is standing water on the shower floor.

Ken

I have never had this issue in my 30' Classic. I have an engineering line drawing of the chassis including the tank placement. It clearly shows three ports in the top of the tank. One for the shower and sink (y'ed together as I recall from looking under the closet floor. One for the vent stack. These 2 are curbside. The other is streetside and is for the bath sink.

[Gringo]

Wow. A whole bunch of lights just went on here, too. (They're very noticeable in the darkness that usually fills the space between my ears.) We just recently had gray water issues on our first trip in a '11 27FB. I saw water in the shower, and assumed the tank was full. The light on the status thing has never worked in this trailer, so that was not in the evidence. Just water backing up into the shower. I assumed the valve wasn't opening, as I had no other ideas on it. We were in a campsite where I left the GW valve closed for the first time, a state park with no sewer hookups. After trying several times to screw the rod into the valve ( duh) I contacted AS and was planning to take the trailer to the local Colorado dealer, cutting our camping portion of the trip short by a day or two. I am SO glad I didn't do that. I won't go into all the things I did, including buying and returning one pump in a hardware store in Taos, but I was left puzzled. I outlined what I did, and the customer service guy in Ohio wrote me that perhaps it had been a bit of debris from construction that obstructed the valve, and that moving from one park to another had dislodged it. I kinda could see that, I guess...but not entirely enthusiastic about it. Now this explains it.

He MUST have been aware of this issue, going on at the exact same time with Bike Addict's trailer. Yet he never suggested I wait to see if the shower slowly drained. Just a thought about valve obstruction, all better now. No more complaint.

Looking back now, I realize that we had probably just soaked and washed the little teflon coated grill and the plastic grease trap that came with our new Coleman propane stove. We had just used it for the first time that night. grilled Steak and (microwave)baked potatos at Palo Duro State Park. We had a full sink of soapy water to cut and dilute the grease. And dumped it as such and as is repeatedly described in this thread. Eureka. Or Portland, maybe.

Of course you guys are completely missing the genius of this design. This is on purpose. You see, by making the fresh water and gray tanks the same capacity, and knowing that a lot of additional fluids are added to the tanks during a trip ( cases of beer, for one example), the clever engineers at Jackson Center almost guaranteed that we would all start using plastic bowls in the sinks, and dumping them down the toilet. They have forced us into a new habit that will minimize complaints about the capacity of the gray water tank, and also insure more thorough flushing of the BW tank by making us add GW through the toilet. It would be very costly to arrange plumbing to automatically funnel gray water into a fitting below the toilet. This is pure genius in both plumbing and advanced psychology.

But I wonder why not just have one big holding tank that is slightly larger than a new, bigger fresh water tank? Say, 50 gallons FW and a 75 gallon single big holding tank? Same total as now, just rearranged.

Wouldn't that solve a whole lot of issues, including tank capacities and drastically simplifying plumbing materials and labor per trailer? In the six years we have been living on this island, I have learned by heart that simple is good.

[Silver Goose]

Originally Posted by Gringo

...But I wonder why not just have one big holding tank that is slightly larger than a new, bigger fresh water tank? Say, 50 gallons FW and a 75 gallon single big holding tank? ... In the six years we have been living on this island, I have learned by heart that simple is good.

I have to agree, the simpler the better. When you suggested one large holding tank, I assumed there had to be a code that prohibited doing that, but according to the RVIA, a single holding tank is permitted.

http://www.rvst.org/rvia_textbooks/p...ems.pdf#page29

See section 1-3.3.5 This pub is 5 years old, and there may have been be changes to this textbook on RV plumbing systems. There's a lot of info in there and many diagrams.

It is my understanding that 50 years ago it was allowable to release gray water directly to the ground. Many trailers of that era didn't have a GW tank. It seems that it became the practice to add a separate tank for the GW and the idea of a single holding tank never caught on. I understand your points, but there are some advantages to separate tanks also.