Gray Water Backs-up into Shower!

[TravelHappy4]

Sent: 8/7/2004

I recently purchased a 1987 Winnebago Itasco and am having a problem with the kitchen and bathroom sinks backing up into the shower. The toilet (which is between the bathroom sink and shower) does not do this.
We have taken a snake and gone all the way through the pipes and found no blockage. We had to take a small portion of the pipe out (in order to get the snake all the way thru the line), and the shower drains fine. But, when we put the pipe back in - it backs up.
Any help or suggestions would be greatly appreciated.

[nailhead]

Sent: 8/7/2004

Check for mouse/birds nests going into the grey water tank, also, make sure vent isn't blocked.  I had the same problem.  Does the back up go down eventually or does it remain until the grey water is dumped?

[TravelHappy4]

Sent: 8/7/2004

We ran a snake all the way into the gray tank, even from the vent on top of the RV, and all through the system. Didn't appear to be any blockage and we got into the tank itself and was on the bottom so we thought. Water does not go down ventually! We haven't dumped it yet, plan on doing that tomorrow and see if it goes down.

With the small piece of pipe off, there is no problem with the water going out of the shower drain. It's just when we put that pipe back on that water stays in the shower. It's almost as though it were an air problem in the drainage system or something. (I really don't know what I'm talking about - I'm real new to RV's. Just looking for help!!!)
Maybe we should run the snake again with that piece of pipe back on???

Thanks,

[TravelHappy4]

Sent: 8/8/2004

Backup goes down with the grey water is dumped. But when you run water in the shower or in the other 2 sinks, it backs up again in the shower.

[nailhead]

Sent: 8/8/2004

I think you hit the nail on the head with the air problem.  Unless you have a rediculously small gray water tank and its full at the first washing of the hands, there's some sort of venting problem.  Are the previous owners available for comment?  If when you pull the grey water dump it goes down, then the lines must be free and clear.  Silly question, but are you parked on level ground?  I'm probably less knowledgeable than anyone when it comes to RV plumbing, but having been in carpentry the last seven years, I've dabbled in just about everything...just enough to give me the confidence to cause a world of trouble for myself and inspire a dozen trips to the hardware store before I have it patched and rigged together.  Check with the dealer on whether the tank itself requires venting.  It almost sound like you have a gigantic water cooler effect where the water is suspended until the air can vent the lines.  Did the snake show any signs of a blockage that may have just moved?   I'm at a loss, but somehow that water does not have a level path to the grey tank with proper ventilation.  I know, my advice isn't much help.   Let me know how you make out, good luck.

Matt

[DaveVA78Chieftain]

Sent: 8/10/2004 

Most RV's have 2 waste tanks.  Though before approximately 74 they may have only had one tank.   The black tank is used for the toilet and  the grey tank is typically used for sinks and shower.  As you found out, your grey tank was obviously full and backed up into the shower.  Usually, both dump valves (black and grey) feed into one common  sewer pipe connection.  Rule of thumb is to let your black tank get fairly full before dumping it.  Say 3/4 or more full.  This allows enough liquid to build up such that when you do dump the tank everything will be flushed out.  Depending on your rig and your usage, you may find you have to dump the grey tank a few times before the black tank fills up enough to allow proper flushing.  I know my grey tank is far to small for the size black tank I have.  I have seen many people complain about that no matter who built the rig.

  When you do dump your black tank, dump it first, then dump your grey tank.  This will allow the grey water to help flush the piping of any remaining material from the blank tank.  Be sure you close both dump valves after flushing.  One of the most unpleasant situations you will ever encounter is pulling off the dump pipe cover cap only to discover that the dump pipes are full and end up with the mess all over you and the ground (been there, done that).  Though I suspect it happens to most people at least once in their RV life.  I think thats one of the reasons dump stations typically have a large concrete pad area that allows the liquid to drain to the dump connection.

  BTW, there should be a monitor panel installed by Winnebago mounted somewhere in your rig.  You should be able to read the tank levels (grey, black, and fresh water) there.  Thats how you know when to dump the tanks or fill the fresh water tank.  The panel may also have the water pump switch and may even include the furnace thermostat.  Later models may even include battery condition indicator for the house battery.

Dave

[LVLFNXS]

Sent: 9/5/2004

Hey,
The reason why your *grey water* backs up into the shower drain is because the shower drain is the lowest of the grey water drains.  Also, there is probably no holding tank for grey water, as there is none on my as well, when you put enough grey water in the system with out draining it, it fills up, thus, the shower is the first drain it comes to.  The only way to make it so it doesnt is do one of two things. 1)  about the time when it backs up into the shower, open the vavle to the black water tank so most of the grey water goes into the black water tank(remember, NOT to open the sewer drain hose cap), or 2), hook your drain hose up and empty the system as usual.   If you want to see how your sewer is routed, there should be a schematic either through winnebago, or in your owners manual. Hope that helps.

Erik
Seattle, WA

[MSN Member]

From: TravelHappy4
Sent: 8/19/2004

Problem SOLVED!!!

I did say we were new to RV's! It helps to not only read the manual, but look at the pictures!!! We have two waste tanks. We were only aware of one. Anyway, after reading the manual again and looking at the picture, we checked to see if our had another tank and sure enough, it did. After emptying the 2nd tank we no longer have a backup problem. Talk about feeling stupid!

Thanks for your comments and help.

[Froggy1936]

Hi. On this subject, I purchased from Media camping Center 4 sensors for water level $ 1.75 ea (they are just a stainless bolt & nut thru a rubber grommit  tightening the nut expands the grommit and seals the hole) Then drilled 2 holes in ea tank 1 near the bottom the other about 3/4 of the way towards the top The lower 2 are ground connections The upper two i wired to indicator lamps with switches. When either tank reaches 3/4 full the lamp lights  This is an easy cure for vehicles without sensor panel installed at the factory  Frank

[ClydesdaleKevin]

Just a side note...grey tanks fill VERY fast!

Two showers fill our 40+ gallon grey tank in no time, what with washing dishes and shaving and whatnot.

We usually keep the grey valve open to the sewer line at all times, with the black closed.  When the black is almost full, I'll close the grey for a day or so until I'm ready to dump the black.  Once the black empties I open the grey.

Again, the grey fills VERY fast.  You'd be surprised how much water you use once you become a fulltime RVer!

Kev