Black Water Tank Vent Pipe Question

[Suncircles]

The vent pipe from my black water tank has pulled itself down from out of the roof flange about 2" and now vents tank fumes directly into the coach. On my '05 Journey 36G this vent pipe is behind the control panel next to the toilet room, so it can be readily accessed by removing the panel. I can pull up on the pipe and insert it back into the roof flange, but, apparently the plastic tank has distorted enough that it pulls the pipe back down when I release it. I called Winnebago Customer Service to see if there was a fix. Their suggestion was:

Cut the vent flange from the roof; cut a bigger hole in the roof so that a 1 1/2" coupler can be inserted over the vent pipe; insert 1 1/2" pipe into coupler that is long enough to go up through the flange. Replace the flange and re-seal it.

I am uneasy in breaking the seal between the flange and the roof top. I am also uncomfortable in cutting a bigger hole in the roof to accommodate a coupler. Basically there must be an easier solution to extending the black water tank vent pipe back through the roof. Has anyone had/fixed this problem without having to do a lot of cutting?

Suncircles
2005 Winnebago Journey 36G with 2006 CRV tow.

[bdpreece]

Since you have access from inside cut the pipe off down far enough so that you can install the coupler well below the roof line then remove the roof flange and drop a longer pipe down through the hole. I would not be nervous about removing the roof flange in fact I would want to remove the old vent cap and install a cyclone vent while I was at it.

[wa8yxm]

Flange is most likely soft rubber. You can slip a coupler down in no problem

If the inner pipe is black PVC the coupler fits INSIDE the pipe by the way

You only need to remove the top of the flange,, ,Likely one screw holds that to the visible "pipe"

[DancinCampers]

There is a rubber gasket in the tank that seals around the black pipe. There is supposed to be an attachment holding the pipe from falling thru. Mine was a cable screwed to the wall, attached to the pipe with a hose clamp.

I think you will need to replace the gasket and then secure the pipe.

If you just extend the pipe, it will fall to the floor of the tank and you will not have a vent.

If you secure the pipe so it stays in the tank AND is above roof line, you MAY or MAY not get fumes from around the gasket.

In my case the pipe was too short, and it was attached so it was above roof line, but not fully thru gasket. This allowed fumes to circulate in the basement are, being pulled into coach when a/c operating. I extended the pipe with a coupler and pipe.

[ROMAD]

Had the same thing happen on my 06 Voyage 33V, but both the black and the grey vent stacks sank below the roofline. Winnebago repaired them both at GNR last year but it took 2 1/2 days! Was lucky as Winnebago covered the cost as a defect. Got to love that kind of customer service!

[SoIlBoy]

I had the same problem on my 36G, black tank vent pipe only. Today I cut the pipe in the space behind the control panel and inserted a 4 inch piece of pipe. The bottom of the pipe would not move up or down, or turn when I tried to move it, so I assume it is sealed ok at the tank, it looked ok when I looked down at it. I was able to push the upper piece of pipe up through the roof without any modification to the roof.
When you cut that pipe, be ready for the smell to get very strong.
I now have the vent fan going and a window open and will close it up and turn on the A/C tomorrow.
About a 1 on the difficulty scale.

[Suncircles]

Thank you for all the input. It seems that I am not the only one who has had this problem. Cutting the vent pipe and inserting a 2 inch extension seems to be the simplest solution.

I believe the factory installed the black water tank vent pipe correctly. The gray water tank vent pipe is in the correct position. Since the black water vent pipe seems to be firmly connected to the tank (i.e. it has not fallen in), the tank must have deformed downward over time, pulling the pipe down out of the flange on the roof. (I found residue of silicone sealant around the pipe about 2 inches down from the top.) The rest of this sealant is on the inside of the roof flange hole. The factory did not attach the black water vent pipe to the wall in my coach, so it flops loosely compartment behind the control panel. After installing the extension I will then reseal the pipe in the roof flange with silicone sealant.

The cyclone vent on top of this pipe sounds like a good idea. There are many different models on the market and I have not found a good comparative evaluation of the various models on the internet. I may consider such a vent down the road should odors persist in the coach after the repair is complete. If you know where I can find such an evaluation I would appreciate hearing more about them.

Thank you again,

Suncircles
2005 Journey 36G with 2006 CRV toad

[GENECOP]

The simplest solution is to install the Cyclone now, The most popular and original Cyclone has a 5" extension sleeve at the bottom, it also comes with a flange, simply place the flange over the hole, slide the Cyclone down over the short pipe, (if your current pipe is 2" below the roof, the new Cyclone will now be about 3" above the roof line), Now lift the flange, run a bead of sealant around the new cyclone pipe that comes through the roof, Then a bead under the flange, set the flange in the bead, then lastly run a bead at the seam between the flange and the pipe coming through it. This is the best way to deal with your situation, you will make the repair, and at the same time upgrade your vent cap, Gene

[JC2]

Originally Posted by GENECOP

The simplest solution is to install the Cyclone now, The most popular and original Cyclone has a 5" extension sleeve at the bottom, it also comes with a flange, simply place the flange over the hole, slide the Cyclone down over the short pipe, (if your current pipe is 2" below the roof, the new Cyclone will now be about 3" above the roof line), Now lift the flange, run a bead of sealant around the new cyclone pipe that comes through the roof, Then a bead under the flange, set the flange in the bead, then lastly run a bead at the seam between the flange and the pipe coming through it. This is the best way to deal with your situation, you will make the repair, and at the same time upgrade your vent cap, Gene

I agree. We have one on our black tank roof vent and also have one to put on the gray water roof vent. They can also get testy.

[Suncircles]

GENECOP and bdpreece;

Thank you for the Cyclone suggestion. I went out today and bought a Cyclone Vent System from CW. I will climb up on the roof and do the "fix" when the temperature drops below 100. What would be the best all-weather caulk to use?

Suncircles
2005 Journey 36G with 2006 CR-V Toad

[GENECOP]

I like PARLASTIC, Its a flexable rubber based sealant available at RV supply stores, comes in white, just clean the surface well with acetone or equal, good luck, Gene