Black Tank Venting?? 2019 Minnie Winnie 22R

[The Gabe]

2019 Minnie Winnie 22R
I flushed the black tank for the first time in this new to me motorhome, which I love, by the way.
With the black tank drain valve closed, I ran 20 gallons of water into the tank via the black tank flush port. I would then turn off the water and release the black tank drain valve so the black tank would get a rush of water driving the waste out. I did this 3 times until he exiting water looked clean.
When I was done, I went into the camper and found water had run from the bathroom into the rest of the camper. There was no sewage smell at all. I looked into the toilet and there was no water in it although I had left it approximately one third to half full.
My current theory is the pressure from filling the black tank forced air up through the toilet seal blasting the water that was in the toilet out of the toilet and into the camper. I read the Owners Manual and it states to flush with the drain valve open. Is there no vent for the black tank? Is my theory correct?
Thank you.

 

[Morich]

It sounds like there are a few points to check as there is a vent built into both the black and grey tanks!
But never fully trust info from the net as it can be as suspect as any story you read!

In this case Winnebago has given us a really nice tool to use to look at what they built! And we don't even have to go outside to take a look under the RV!

The interactive parts catalog is great for this:

Parts Catalog

If we go there and sort down to drainage, we can get a look at what we should find here:

Cortona3D Solo Universal Viewer

If we take a look at the holding tanks:

Black waste goes into the tank that shows brown here? Black waste should go in with air going up and out the vent! Ignore the loose parts as they are for options.
The black and grey tank vents are combined along the path somewhat near the roof?
In this view black on left, grey on right.

But if we take a close look at that venting and follow the pipes, I notice something a bit different as the vanity sink drains to the black tank!

So that brings the question about how and where the water gets in the floor! Flushing water in should make air go up and out the totally open vent before forcing through the seal as well as standing water in the stool?
The vanity sink trap should also hold water to trap gases from coming inside but make that go up the vent also!

Long story gets around to my thought that the vent is near totally stopped up with something! It takes a pretty good seal to let you blow water out of the stool or trap when air moves so much easier than water?

Assuming nobody has been on the roof and dropped a beer bottle down the vent, I'm betting there is a great big paper wasp nest blocking the vent???
Maybe time to take the vent cap off, shove a hose down and see if you clear it? Maybe run a fish tape with a hook on the end to see what you can snag out?

Don't we just love mysteries like this? ARRGH!

 

[The Gabe]

Morich, this is a totally awesome response. Thank you so much for taking the time to share this. I also suspect the vent is clogged. Thanks, again!!

 

[Morich]

I've even been to "nixie"!
Funny how small the world at times!

Let me add one more serious thought?
I was thinking about where and why wasps might choose the vent stack to build and it occurred that one of the things they seem to like is dry. Maybe there is a big old nest built all around under the cap.

Approach with care !

 

[The Gabe]

I've even been to "nixie"!
Funny how small the world at times!

Let me add one more serious thought?
I was thinking about where and why wasps might choose the vent stack to build and it occurred that one of the things they seem to like is dry. Maybe there is a big old nest built all around under the cap.

Approach with care !

Hey, Morich, Yeah, I used to live in Nixa, but have since moved to Wichita, KS - I've updated my Profile. I don't know if you know, but Nixa is the "home town" of the fictional character Jason Bourne.

 

[Morich]

Actually I was going on the thought that you might be related on my wife's side of the group! I think we have a Gabe in Nixa!

 

[The Gabe]

Actually I was going on the thought that you might be related on my wife's side of the group! I think we have a Gabe in Nixa!

Sorry, no relation. I'm "The Gabe" because Gabe was a nickname of my grandfather's whose last name was Gabel. Plus, it was a nickname of fur trappers who were respected and experienced, both of which I am not, but I like the fur trapper culture and history.

 

[Kelly k-WO]

2019 Minnie Winnie 22R
I flushed the black tank for the first time in this new to me motorhome, which I love, by the way.
With the black tank drain valve closed, I ran 20 gallons of water into the tank via the black tank flush port. I would then turn off the water and release the black tank drain valve so the black tank would get a rush of water driving the waste out. I did this 3 times until he exiting water looked clean.
When I was done, I went into the camper and found water had run from the bathroom into the rest of the camper. There was no sewage smell at all. I looked into the toilet and there was no water in it although I had left it approximately one third to half full.
My current theory is the pressure from filling the black tank forced air up through the toilet seal blasting the water that was in the toilet out of the toilet and into the camper. I read the Owners Manual and it states to flush with the drain valve open. Is there no vent for the black tank? Is my theory correct?
Thank you.

Ihad the very same issue 2weeks ago, clean water all iver the floor, heading the responses from your post awasp or mud dobber next sounds likely, we have a bunch of those here in Georgia, thank you for posting your question, l learned something valuable tonight!

 

[The Gabe]

Ihad the very same issue 2weeks ago, clean water all iver the floor, heading the responses from your post awasp or mud dobber next sounds likely, we have a bunch of those here in Georgia, thank you for posting your question, l learned something valuable tonight!

Hey, Kelly k-WO, I recently saw a YouTube video by Hillbilly RV Repair (I don't recall the original post date) where he says the cause of the problem is that you aren't suppose to fill the black tank with the drain valve closed - this is also stated in my owners manual. He said this will build pressure in the tank and possibly blow out the seals in the commode or rupture the tank. This really doesn't make sense to me because of the vents. I'm taking the camper in to have some other work done (not a Winnebago dealer) and I'll ask their opinion.

 

[Morich]

It would seem to make one wonder about the purpose of a VENT? If air doesn't go out the vent as water comes in, what does the vent to do for us? \
I'm afraid the internet and ease of anybody posting may have opened the information doors a bit too wide!
I had a report that we should not be swimming when the planes were making chemtrails! I thought we had a very pretty sunset last night!

 

[Kelly k-WO]

Hey, Kelly k-WO, I recently saw a YouTube video by Hillbilly RV Repair (I don't recall the original post date) where he says the cause of the problem is that you aren't suppose to fill the black tank with the drain valve closed - this is also stated in my owners manual. He said this will build pressure in the tank and possibly blow out the seals in the commode or rupture the tank. This really doesn't make sense to me because of the vents. I'm taking the camper in to have some other work done (not a Winnebago dealer) and I'll ask their opinion.

When you get their opinion please update! Great info, thank you

 

[lenore-WO]

We just recently had someone find a broken fitting from the washout. this allowed water over the floor.

 

[The Gabe]

We just recently had someone find a broken fitting from the washout. this allowed water over the floor.

I looked inside the camper during the first flush and there were no issues. I found the water on the floor after I had filled the black tank 2/3 full a couple of times.