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rochar3 · 10-02-2013, 07:48 AM

My gray ewater tank is backing up into the shower. Tanks is empty and doesn't seem to have any blockages because I can force water thru the pipes into tank, but after while, gray water seeps into shower. Any suggestions on how to clean etc would be appreciated. AS is '03 31 ft classic. Thanks for your help

Will_Brule · 10-02-2013, 08:03 AM

The shower drain is obviously the lowest drain. Does it back up when draining water from the galley sink or the sink in the bath? Sounds as if the water is never reaching the gray tank. All three drains are probably plumbed to a common line that enters the gray tank. That line is likely the location of the blockage point.

murreywalker · 10-02-2013, 08:22 AM

Quote:

Originally Posted by rochar3

My gray ewater tank is backing up into the shower. Tanks is empty and doesn't seem to have any blockages because I can force water thru the pipes into tank, but after while, gray water seeps into shower. Any suggestions on how to clean etc would be appreciated. AS is '03 31 ft classic. Thanks for your help

Have you checked the breather vent on the roof?

HowieE · 10-02-2013, 08:59 AM

The shower is generally dumps directly into the tank, without any other piping. Water shows in the shower when the tank is full.

If the tank and drain valve are clear you should be able to open the drain valve and run water from any of the sinks and see it come out the drain at once. If that is OK try running water into the shower and see if it drains from the drain valve. If it does not I would think the shower drain is clogged. Not sure what the source of water is that you see in the shower.

To clear the shower drain I take a simple rubber drain stop, drill a 1/2 in hole through it and force water from a hose through the shower trap. Beach sand tends to clogg the shower trap.

Your description that the tank is empty and water seeps into the shower flies in the face of the laws of plumbing 101.

robert claus · 10-02-2013, 09:26 AM

Are you sure the grey tank waste valve is not broken? You may be pulling the handle, but if it broke off from the gate it may not be opening. Like Howie said, open the drain valve and run water through each drain to see if it comes out. If you get anything, the drain valve is okay, and you have a clog somewhere. If you get nothing, the valve is not opening.
Is this a center bath layout or rear bath?

InsideOut · 10-02-2013, 06:22 PM

I suspect it's one of two things:

1) Broken grey tank valve or
2) Vent (usually on roof) needs to be cleaned

I know they were both mentioned, but those really are the only two options if you are certain there isn't any blockage anywhere else.

Shari

LAWBC · 10-14-2013, 11:28 AM

We have been camping for 5 days. My wife mentioned to me that she heard a sound coming from the shower. So, I got her to fill up the sink, then release the water and almost immediately water was backing into the shower making a gushing sound of water and air, blowing up a couple of inches and leaving about a couple cups of water.
I checked the water temp in the shower and it was cool, not nearly the same water temp from the sink which was all hot water .

BTW-Grey tank was emptied before I did the test, and we performed the test several times all with the same results
This trailer is barley 5 months old and we are careful about putting food scrapes down.
So I am thinking to try Liquid Drain-O.
The absolute funny thing about this whole thing is, our friends that we are camping with have a 20 year old Winnebago gas puller and commented that he had this problem in his unit and we where trying to figure that out only to find out the next day I had the same problem

Could this be a virus, (LOL) What should I do? Does the vent have some sort of a one way valve that could be hung up?

xrvr · 10-14-2013, 11:53 AM

This us a common problem. I will try to find the threads. Drain the water slowly and it should not back up. Jim

Ridgerunner3 · 10-14-2013, 12:29 PM

Quote:

Originally Posted by zigzagguzzi

This us a common problem. I will try to find the threads. Drain the water slowly and it should not back up. Jim

I also remember reading a long thread about this problem with a relatively new trailer. I'll help search for the thread.

Ridgerunner3 · 10-14-2013, 12:40 PM

This is the thread I was thinking of. The problem described in the thread may or may not relate to your issue. Do your sinks back up into your shower when you think the grey tank is empty?

http://www.airforums.com/forums/f444...sue-83758.html

Alumaholic · 10-14-2013, 01:05 PM

Please open your gray water dump valve. Then systematically do the following:
1. Put a gallon of water down the bathroom sink drain. Tell us how much comes out the dump valve.

2. Put a gallon of water down the kitchen sink drain. Tell us how much comes out.

3. Put a gallon of water down the shower drain. Tell us how much comes out.

Once you provide this feedback, we will gladly diagnose your problem.

TBRich · 10-14-2013, 03:30 PM

An additional note: I would hesitate to use anything as caustic as Drain-O in your plumbing system.

LAWBC · 10-15-2013, 08:06 AM

Did the 1 gal @ diff locations and found everything was flowing and no over spill into the shower. Then filled the kitchen sink + 1/2 way again , thinking about 3 gals and filled the bath sink , then let her go .
There was a slight air bobble in the bath sink , then a slight blow back @ the shower and I say approximately 2 oz. of water if that.

I realize my first observations probably exaggerated the quantity of water in the shower ( it wasn't cups but a couple of oz.)
The water coming up is probably from the trap
We have never noticed before because we had company and my wife used more water in that large round sink we have done before .
I think its all good but will check the vent stack for blockage just in case and if I find any there will post another update .
In future I going to leave the plug in the shower as I did a large volume water test with the plug in and it held back any water and air.

HowieE · 10-15-2013, 08:37 AM

Quote:

Originally Posted by LAWBC

Did the 1 gal @ diff locations and found everything was flowing and no over spill into the shower. Then filled the kitchen sink + 1/2 way again , thinking about 3 gals and filled the bath sink , then let her go .
There was a slight air bobble in the bath sink , then a slight blow back @ the shower and I say approximately 2 oz. of water if that.

I realize my first observations probably exaggerated the quantity of water in the shower ( it wasn't cups but a couple of oz.)
The water coming up is probably from the trap
We have never noticed before because we had company and my wife used more water in that large round sink we have done before .
I think its all good but will check the vent stack for blockage just in case and if I find any there will post another update .
In future I going to leave the plug in the shower as I did a large volume water test with the plug in and it held back any water and air.

Your experiment indicates a blocked vent on the gray tank. If the vent was open there would be no chance of building pressure in the tank to the point it forced the shower trap water back up into the shower.

jdalrymple · 10-15-2013, 08:46 AM

Not sure this applies to your model, it is a known issue on some of close vintage.

The kitchen sink drain is tee'd into the vent pipe. When a large amount of water is dumped by pulling the drain plug on the kitchen sink, the large slug of water occludes the path of air being forced out of the gray tank.

The next easiest path out of the tank is the shower drain. This bubble of air forces the contents of the shower trap into the shower floor.

There is a special valved device that can be used to replace the trap that slows the flow of water and helps with the problem, but I can't remember the name. Maybe someone will chime in.

Regards,

JD

HowieE · 10-15-2013, 08:55 AM

Sounds like you have pinpointed the location of the clog. If his trailer does in fact have a WET WENT, plumbing term.

If that is the case and it takes a half sink of water to produce the effect one might just cut down on half filling the kitchen sink with water.

jdalrymple · 10-15-2013, 12:25 PM

The name of the device I mentioned is a HEPVO valve.

It is a P trap alternative that has the side effect of slowing down the drain flow a little.

Regards,

JD

murreywalker · 10-15-2013, 01:21 PM

Quote:

Originally Posted by jdalrymple

The name of the device I mentioned is a HEPVO valve.

It is a P trap alternative that has the side effect of slowing down the drain flow a little.

Regards,

JD

AND, in the instance of at least the 25 and 27 FC FB, installation of the Hepvo valve buys you a bit more cabinet space under the sink.

It's win, win. No more glug, glug, and the wife thinks you're a hero for giving her that extra bit of room to store more jun…er stuff.

TG Twinkie · 10-15-2013, 06:32 PM

Obviously A$ has no one in their design department that knows anything about DWV systems.
If they did, these problems would not exist.
Backing up into the tub/shower with a full GW tank is one thing. But when you can't drain the galley sink without water coming up in the tub/shower. It's just poor design!

Silver Goose · 10-15-2013, 07:19 PM

Quote:

Originally Posted by jdalrymple

... The kitchen sink drain is tee'd into the vent pipe. When a large amount of water is dumped by pulling the drain plug on the kitchen sink, the large slug of water occludes the path of air being forced out of the gray tank. The next easiest path out of the tank is the shower drain. This bubble of air forces the contents of the shower trap into the shower floor ...

I have an '07 27FB and this confirms my suspicions. If I dumped a full sink, water momentarily bubbled up in the shower, a lesser amount did not. As I recall this was only noted if the GW dump valve was closed regardless of the tank level. If the valve was open, the open ended sewer line offered no restriction for this volume of water flowing into the tank, acting as if the vent was restricted. I verified the vent was clear from the roof down and with the hook on the end of the tape measure confirmed the pipe was't sitting low in the tank. My conclusion was that the galley and possibly the bath sinks used a wet vent to simplify the design, but the limited length and diameter of the pipes could not absorb that volume of water without finding relief through the shower drain.