Gray water backs up into shower pan

[ClydesdaleKevin]

Sent: 5/16/2005 9:54 PM

Well, today I had to replace a pipe under the sink coming from the hot water heater that must have burst at one point in its life from not being winterized.  Replaced it, inspected all the copper lines, and no leaks!

While running all the faucets today, however, I noticed an interesting thing that I'm not sure is SUPPOSED to be like this (probably not), or if some PO just did a horrible job at (more likely).

My shower pan started to fill with water after about 5 minutes!

It was coming up from the drain!

So, I turn off the water, look down the toilet, and there was plenty of room in the holding tank.

Hmmmmmmmmmmmmm.  I go outside and look at my new sewer valve, and its closed.  So, I take off the cap to the sewer drain pipe, and am deluged with water from the drains!

I hook up the hose, open the valve, and the water in the holding tank (from the running toilet...had to check it for leaks too) comes pouring down the hose.

I try an experiment:  I put the cap back on, open the valve, and run the water.  It runs continually without filling the shower pan, and enters the holding tank.  I close the valve, and  a few minutes later the shower pan starts to fill.  I open the valve, and the shower pan drains into the holding tank!

I get under the rig and think things out.

AH HA!

There is only ONE sink that drains directly into the holding tank, and that is the bathroom sink.  It only drains into the holding tank because it is in line with the sewer vent pipe (there's a gas trap on it, so I'm not worried about it).  The kitchen sink drains into a main drain pipe, which for some reason goes to the back of the coach, and then back forward to a collection of drain pipes which meets under the shower pan drain next to the holding tank, and enters the big collection pipes that has my sewer valve and outlet.  There is a picture of it in the back of the Ark album The Ark, 1972 Futura

So, here is my dilemma.

My drain lines enter the big pipe AFTER the sewer valve!

My greywater just sits in the pipes, and is only held in by the cap that goes on when travelling!...lol

Is it supposed to be like this, or was the PO in reality Mickey Mouse?

I traced all the drain pipes, and there just isn't anywhere under the coach where a greywater tank might have at one time been placed.

I have three options:

Option one:  Leave it like it is, make sure the tank and drains are empty before travelling, and if any water is used in transit, deal with getting a little wet when taking the cap off before attaching the hose.  When boondocking, one advantage would be that only the greywater would drain out the hose.  I couldn't leave the valve open to let it run into the holding tank, because then it would be drainwater AND poop when I opened the cap...EWWWWWWW!

Option two:  Slightly modify it and install a ball valve right before the drains enter the big sewer outlet pipe.  This would keep me dry when I open the cap to attach the hose, with no poop residue.  This would severely limit my holding capacity when travelling, but I could still run the water a little bit on the road if I had too provided I start the trip with empty tanks and drain lines.

Option three:  Install another very short section of big drain pipe with the big square flange at both ends, and install another sewer valve, so there would be one before, and one after, where the drain enters the line.  Then I could use the holding tank for greywater and blackwater, and wouldn't get a nasty surprise when I remove the cap to install the hose.  Both sewer valves would stay open at campgrounds and with the hose attached, but in transit or while boondocking, the outside valve could stay close, the inner valve nearest the holding tank could stay open, and I would have the whole capacity of the single holding tank.  The drawback to this is PARTS!  I haven't looked yet, but I seriously doubt anyone makes a very short big drain pipe with TWO square flanged ends!  This seems to be the best and most cost effective option, but it have no idea where to find the plumbing!  If they make just a flanged end with a female input, I could buy two and glue a very short connecting male pipe between them.  This would work if I can find the parts!

Option four:  This isn't an affordable or time effective option at this time...I would have to purchase a greywater holding tank, and SOMEHOW find a place for it under the coach, replump the whole thing, and still have to tie it into the system with valving as described in option two or three.

Any suggestions, folks?  Are any of your rigs plumbed this stupidly?

Thanks!

Kev and Patti Smith

[DaveVA78Chieftain]

Sent: 5/17/2005 9:51 AM

While having a grey and black tank is convienent, you do not absolutly have to have them both.  Can you replumb such that all drains feed to the black tank?  The connection point would be to the black tank outlet pipeing before the discharge valve, it should back fill into the tank.  This way, there would be no water at the discharge cap until the valve is opened.  The traps at the drain should prevent oder from being an issue.

Dave 

[ClydesdaleKevin]

Sent: 5/17/2005 12:32 PM

That's what I was thinking, Dave.  Thanks for the suggestion!  Looks like I'm gonna have to go to an RV store on the next rainy day and buy some fittings!

Kev and Patti Smith

[ClydesdaleKevin]

Sent: 5/22/2005 7:00 PM

I replumbed the drain lines, and added a valve!  Its actually a pretty good system now...I can select exactly what drains to what, and what drains out the hose, just by changing valve combinations.  I now have a dual valve system, with the greywater drains entering BETWEEN the valves.  With the valve near the spout closed, and the one with the tank open, grey and black water now share the one tank!


Kev and Patti Smith

[Stripe]

Did this happen with the RV you had PRIOR to the HR?

I ask because I had the same grey water backup problem on mine only to discover I generate more grey waste than black and had filled the grey water tank faster than I did the black.  Would be nice to be able to divert overflow to the black tank.

[ClydesdaleKevin]

LOL!  That's an OLD post from our first RV, The Ark.  We use a composting toilet on our HR,and I replumbed the black tank to make it an additional grey tank.  We can hold a lot of grey water now!

Kev

[Stripe]

I thought as much. I had forgotten you had switched over to a Composting toilet.

Thanks!