Journey 36M 2012 Bathroom Plumbing Issue

Richard907 · 11-22-2012, 11:47 AM

Does anyone have the below described situation.

The bathroom lavatory empties waste water into the black water tank. The lavatory pressurizes the black water tank and when you use the toilet it blows air thru the toilet and splashes on the toilet seat, and the floor. The situation gets worse as the black water tank fills. We have had this issue since purchase; however it is worse since we are now full timing.
I called Winnebago they told me they thought the vent is blocked and sent me a picture on how the venting was accomplished. I have snaked the lavatory drain to the black water tank and there is no blockage. I have filled the lavatory and drained the bowl. You can physically hear the water drain quickly into the black water tank. I pressurized the lavatory with air (using a wet vac) and the vent tube to the roof is clear.
There is no Anti-Siphon Trap Vent on this line. On the grey water tank, each sink and washer has a vent.
Does anyone have a suggestion as how to eliminate this probleme?

John Hilley · 11-22-2012, 12:38 PM

It doesn't seem possible that it could pressurize if the vent to the roof is clear. How did you check the vent to the roof when you pressurized with the vacuum?

ernieh · 11-22-2012, 12:46 PM

My 03 Journey used to do the same thing when the "dreaded pile" partially blocked the toilet outlet. The other things that you might check are if the vent pipe has slipped down into the tank or the toilet transition piece is extending into the tank too far.

rvrepairnut · 11-22-2012, 01:03 PM

Quote:

Originally Posted by Richard907

Does anyone have the below described situation.

The bathroom lavatory empties waste water into the black water tank. The lavatory pressurizes the black water tank and when you use the toilet it blows air thru the toilet and splashes on the toilet seat, and the floor. The situation gets worse as the black water tank fills. We have had this issue since purchase; however it is worse since we are now full timing.
I called Winnebago they told me they thought the vent is blocked and sent me a picture on how the venting was accomplished. I have snaked the lavatory drain to the black water tank and there is no blockage. I have filled the lavatory and drained the bowl. You can physically hear the water drain quickly into the black water tank. I pressurized the lavatory with air (using a wet vac) and the vent tube to the roof is clear.
There is no Anti-Siphon Trap Vent on this line. On the grey water tank, each sink and washer has a vent.
Does anyone have a suggestion as how to eliminate this probleme?

maybe the pipe from the toilit to the BWT is too small and air locks as it trys to drain.I had this happen in a house I had built.when the washing machine discharged into the drain pipe it was too small in diameter to accept the flood of discharge water and would blow back.larger pipe fixed it

rream · 11-22-2012, 04:45 PM

Same motor home and no problems, had it one year, 7000 miles and 144 days of camping.

lwasouth · 11-23-2012, 09:13 AM

Have 2005 Itasca Horizon - Had the same problem plus water from wash basin going into the black tank tended to fill black tank to quickly. Some people camp with the sewer hose drain open and end up with all the solids still in the black tank. Under my sink cabinet were 2 drain pipes. One was the vent pipe for the black tank which my basin drained into. The other was the drain pipe for the shower. I moved the basin drain to the shower drain pipe. Had to remove most interior parts of cabinet to access pipes, but worth the effort.
Solved both problems

rvrepairnut · 11-23-2012, 10:42 AM

Quote:

Originally Posted by lwasouth

Have 2005 Itasca Horizon - Had the same problem plus water from wash basin going into the black tank tended to fill black tank to quickly. Some people camp with the sewer hose drain open and end up with all the solids still in the black tank. Under my sink cabinet were 2 drain pipes. One was the vent pipe for the black tank which my basin drained into. The other was the drain pipe for the shower. I moved the basin drain to the shower drain pipe. Had to remove most interior parts of cabinet to access pipes, but worth the effort.
Solved both problems

how did moving a sink drain solve the toilit vent/blow back problem?

dengraham · 11-23-2012, 11:21 AM

I think Ernieh is on to the answer. If the vent pipe slipped down to far, then you do not have a vent after a certain amount of water (or other) fills the tank. Was the tank empty or full when you pressurized the tank to test the vent?? I have heard on this site of other vents slipped down. This would cause the blow back you are getting. (It may have stopped it for Iwasouth because the black water got as high up the tank after stopping the water basin from draining into the black tank.)
You will have to ask Winnebago how to determine if the pipe had dropped. If I remember you take off the top on the roof and you can tell if the pipe is loose or dropped. Let us know what you find out.

DancinCampers · 11-23-2012, 02:05 PM

There are only 2 connections to the top of the black tank, the toilet pipe, which is straight down, and the vent pipe. The vent pipe enters the black tank at a near 90 deg angle, so doubtful it fell into the tank, although the end could be too long. You should be able to look at this thru the toilet pipe with camera or mechanics mirror.

This vent pipe continues to the roof in the wall behind the one place panel. The bathroom sink ties into this vent pipe with a p trap, thus no need for extra vent.

The grey water vent pipe ties into this vent pipe just below roof line. When you pressurize with wet/dry vac the roof vent outlet could still be blocked.

I would pull the toilet myself.

We have not had any such issue with ours, been fulltimng since Mar.

I do have a different issue with the toilet, the ball won't seal all the way, believe eith the shaft needs lube, or water valve sticking. Have been trying to get repair/maintenance doc from Thetford.

sellhomz · 11-26-2012, 07:06 AM

Do you have the Sani flush on your MH? Mine attaches to the Black tank and has a brass air release valve to the left under my vanity in my 2009 journey 34y. That could be clogged I think mine was when I got my this year.

Doug Sage · 11-26-2012, 08:16 AM

Mine only does that when the tank is nearing full. It does not do it when below half full. I just use that as my indication that it is time to dump the tank.

Richard907 · 12-02-2012, 10:01 AM

The plumbing issue is resolved. The bathroom sink drain/BW vent was installed improperly. The drain/vent was installed with an uphill angle and water remained in the drain/vent acting like the J trap on a sink. Winnebago had a dealer correct the drain pipe angle, and the vent/drain works as it should. No more pressurization of the BW tank. Thank you Winnebago!!