Grey Tank Problem?

[John Geisen]

Hi,

I "may" have a grey tank issue and thought I'd get your input before trying to fix something that may not be broken..

We have a 28' International CCD. We fill the sink in the kitchen about half full to do dishes. When draining the water from this sink some of it backs up into the shower; just enough to go, "yuk"! Then I have to rinse the floor of the shower. Is this normal? We have only been on a few trips and I don't remember it being this way at first but I may be wrong. If this is normal, I apologize for the thread.

BTW, I normally keep my tanks closed until they are about 70-80% full so I can get good drainage. Perhaps I should open one of them?

John

[2airishuman]

hi john

the 04 28 int/ccd came with ONE waste tank of ~70 gallons.

this tank combined poo and wash water.

does the 05 have this single tank or 2 separate waste tanks?
__________

typically on modern streams when water backs UP into the shower pan it is a SIGNAL...

that the wash water tank is FULL (ok, slightly OVER full)...

so PULL the handle and let it empty out.

there should be NO back up into the shower after doing this...

till it's FULL again.
___________

if relying on the micropulse display for FULL, it may need a REcalibration.

the micropulse system and sensors OFTEN malfunction or need service to be reliable.
___________

it's a good habit to keep the poo tank closed till almost full for better dumping and to avoid MOUNDS.

many leave the wash tank OPEN to drainage when on full hookups,

but grease/sludge may develop along the tank walls, pipes or drain lines

so occasionally closing it and FILLING2flush is a good idea.

cheers
2air'

[Inland RV Center, In]

Originally Posted by John Geisen

Hi,

I "may" have a grey tank issue and thought I'd get your input before trying to fix something that may not be broken..

We have a 28' International CCD. We fill the sink in the kitchen about half full to do dishes. When draining the water from this sink some of it backs up into the shower; just enough to go, "yuk"! Then I have to rinse the floor of the shower. Is this normal? We have only been on a few trips and I don't remember it being this way at first but I may be wrong. If this is normal, I apologize for the thread.

BTW, I normally keep my tanks closed until they are about 70-80% full so I can get good drainage. Perhaps I should open one of them?

John

Check the gray tank vent. If some some reason that vent is plugged up on the roof, it would cause the issue your having with your Airstream.

Andy

[John Geisen]

Thanks to both 2airishuman and Inland RV Center. The '05 28' CCD has two waste tanks; black water and grey water. The grey water tank is nowhere close to full (less than half) while this is happening. Yes, I do rely on the Micropulse display. It seems to work properly but how would I check it?

It dawned on me after writing the email that maybe I should keep the grey water tank open whenever possible and only open the black water when it is full. Does this make sense?

I will look for a clogged grey water vent line. That makes a lot of sense. Just not sure how it could get plugged?

[2airishuman]

Originally Posted by John Geisen

...The grey water tank is nowhere close to full (less than half) while this is happening. Yes, I do rely on the Micropulse display. It seems to work properly but how would I check it?...

the simple way to check is EMPTY the wash water tank then close the drain valve.

then FILL the tank with a bucket (measured gallons) via a sink,

and observe the gauge reading UNTIL the water backs up into the shower basin.

the owners packet will specify size (probably 30 or ~35 gallons) which can be compared to the measured FILL buckets...

again one cannot KNOW the micropulse is accurate without checking volume.

certainly critters may have plugged the vent tube (roof top) but it's far more likely the tank is just FULL...

and the readings are inaccurate.

IF the trailer isn't reasonably level the micropulse may not be reliable even if calibrated.

these tanks are SHALLOW so any UNevenness in the trailer will TILT the gauge readings.

cheers
2air'

[2airishuman]

quickly REreading the op description...

IF the shower pan back up is transient and resolves without draining the holding tank...

another possibility is a partial obstruction someplace in the drain lines.

just like slow drains in a household system, there can be 'stuff' in the plumbing lines

which SLOWS drainage enough to back up into the shower basin temporarily.

REALLY warm water, an enzymatic digester, or other line cleaning process may help.

this is pretty uncommon in MOBILE streams but parked trailers may have these issues,

from food, grease, hair and gooo in the drain lines.

also IF the trailer isn't LEVEL (front2rear) and the flow is slightly UPhill these transient drain issues can happen.

lots of stuff to check b4 callin' the professional rv plumber guy...

cheers
2air'

[Gene]

John, have you back flushed the grey tank? This could dislodge any blockages. Perhaps when the plumbing was put together at the factory someone lost their ham sandwich in a drain and by now it has turned into a new life form. Actually, there are reports of stuff being left in strange places at the factory or plumbing being misconnected.

But first, there are several different items to back flush the black and grey water tanks. I use Flush King and I think it's a very good way to get everything out of the black tank, but I also flush the grey tank (once on that one, many time on the other) to get the residual soap and food particles out. If there's something stuck in the grey line obstructing flow, backflushing could help, and it's good to do from time to time.

I have had my Micropulse monitor recalibrated twice under warranty and it's gone bad again. After a while you know how much is in the tanks from experience and start ignoring all those flashing red lights when it says something is full or empty when it isn't.

Gene

[Inland RV Center, In]

Originally Posted by John Geisen

Thanks to both 2airishuman and Inland RV Center. The '05 28' CCD has two waste tanks; black water and grey water. The grey water tank is nowhere close to full (less than half) while this is happening. Yes, I do rely on the Micropulse display. It seems to work properly but how would I check it?

It dawned on me after writing the email that maybe I should keep the grey water tank open whenever possible and only open the black water when it is full. Does this make sense?

I will look for a clogged grey water vent line. That makes a lot of sense. Just not sure how it could get plugged?

Birds.

Andy

[Gene]

Or paper wasps or mud daubers (same thing I think).

Gene

[dmoore]

We also have a 2005 28' International CCD and have had that problem since we purchased it in 2007. It does not matter how full (or empty) the gray water tank is. Our "fix" has been to make sure that we always keep the drain plug in the shower. There is not enough water pressure to force it out; thereby the floor of the shower is kept clean. We had this checked at a dealer early on when we first purchased but they could not find a reason for the backup. I don't know if they checked the gray tank vent but thanks to Andy's tip we will find it and check it out.

Our Micropulse monitor was recalibrated a couple of times (unsuccessfully) and then replaced (while under warranty). The new one fared no better but we decided just to deal with it as we are not near a dealer and it was not important enough to spend anymore time on it. It doesn't take that long before you have a pretty good idea of how full the tanks are.

Debbie

[John Geisen]

Debbie, thank you.

Putting a plug in the shower seems like a good "work around". We use something to catch hair in the drain so I need to find a plug. I can't imagine it is a design issue, although Andy would probably know. I will try to find the vents mentioned by others and make sure they are clear. I guess I'm looking on the curb side. I think there is a plumbing drawing in the Airstream manual so I'll start there. Once I'm sure the vents aren't clogged I'm not sure what to do next.

I phoned the factory and the service rep on the phone seemed confused and just said, "If you bring it in we will figure it out". Thanks but I'd rather not drive to Ohio and pay someone just to figure it out.

At least Debbie's idea will work since almost as soon as the water comes in, it drains back out.

I sincerely appreciate all your ideas.

John

[2airishuman]

don't write off the design issue.

again that unit had a single tank the prior year

so the first go round with 2 tanks they may not have done it optimally.

IF the unit is level and there isn't crap in the lines,

it would appear the shower drain is functioning AS A VENT tube.

while there is water in the trap that helps to control back venting,

with enough PUSH it can still happen. a 2nd owner with the SAME issue is a clue.

since the primary vent is further DOWN the path it may not help with transient water flow in the drain pipes upstream.

the drain cork is a simple/effective way to defeat venting at the shower pan.
___________

there will be 3 vent tubes on the roof.

on my unit the wash water vent is CURB SIDE (hidden in the closet/corner)

a call or EMAIL to tech at the factory should confirm which vent is which on your unit...

or just take a WIFF of the venting aromas from all 3.

cheers
2air'

[Redd]

John,
I'm having the same problem with my 2008 Safari 20' this fall. I notice your posting was in June. Since that posting date have you found the solution that has worked for your situation?

[John Geisen]

Hi Red,

I'm not certain we solved our problem but we did seem to work around it. I did everything mentioned above from the more knowledgable airstream members on the forum. Found no blockages anywhere.

In the end, the drain plug that Debbie mentioned seemed to work quite well. Also, for some mysterious reason I don't think we cooked as much this past summer. Maybe it was the heat. So, cleaning dishes was more one at at time instead of filling the sink like the previous year.

I'm inclined to believe it is a simple design failure by Airstream. Running a sink-full of water into the grey tank seems to exceed it's ability to accept that amount all at once so it temporarily backs up into the shower (yuk) an inch or two and then drains from the shower. A plug in the shower seems to be a good work around.

I wish I had the real fix but not sure there is one.

John

[Inland RV Center, In]

Originally Posted by John Geisen

Hi Red,

I'm not certain we solved our problem but we did seem to work around it. I did everything mentioned above from the more knowledgable airstream members on the forum. Found no blockages anywhere.

In the end, the drain plug that Debbie mentioned seemed to work quite well. Also, for some mysterious reason I don't think we cooked as much this past summer. Maybe it was the heat. So, cleaning dishes was more one at at time instead of filling the sink like the previous year.

I'm inclined to believe it is a simple design failure by Airstream. Running a sink-full of water into the grey tank seems to exceed it's ability to accept that amount all at once so it temporarily backs up into the shower (yuk) an inch or two and then drains from the shower. A plug in the shower seems to be a good work around.

I wish I had the real fix but not sure there is one.

John

John.

The issue is venting.

Check the complete venting system for the gray tank. All the piping and connections.

Lastly, have some colored water in the gray tank. Red usually works fine. Drop a weight rope down the vent pipe from the roof, and see if it has red on it when you remove it.

It's a remote answer, but perhaps the connection to the gray tank, is blocked by the tank itself. Fittings are "spun" onto to the tank. The center of that attachment, must be cut out so that there is now a hole in that tank.

Dumb, but it could be.

Andy

[Gene]

I agree venting can be the problem. If a vent is stopped up, air in the drains has no where to go fast enough as water tries to displace that air and it can force water into and up another drain lower than the sink.

Gene

[Dave Park]

Is it ok to just pour a little Drano clog remover down the vent pipe? Or pour boiling hot water down the pipe?

[noreen&sal]

Negative on the Drano. Probably has lye and will melt something. Sal.

[Gene]

The vent pipe and drains are usually made of ABS, a black plastic. I think it's brittle and more easily melted than PVC, but it's cheap, so it's used for drains. Since people pour all sorts of chemicals down the drain, I expect it can take some pretty noxious chemicals, but I'd check before using something like lye. I'd try a snake first and try to dislodge a blockage that way.

Gene

[Dave Park]

It has lye, and the PVC vent pipe and ABS tanks are not affected by lye. Nor are brass or ABS drain fittings, PVC cements, etc.