Black water odor while driving

[Windowsofaspen]

I have a 2016 Mercedes Galleria and everytime I drive it it smells like black water inside the unit the bathroom doesn't smell I'm not sure where the odor is coming from? If anyone has any tips or help please help. Thank you
Is there some type of valve on top of the tank?

[DUTCH in Atlanta]

Originally Posted by Windowsofaspen

I have a 2016 Mercedes Galleria and everytime I drive it it smells like black water inside the unit the bathroom doesn't smell I'm not sure where the odor is coming from? If anyone has any tips or help please help. Thank you
Is there some type of valve on top of the tank?

There's a vent up top, but no way to close it.

Try adding one of the commercial black tank additives that has odor control properties. Some folks say that Downy fabric softener, when added to the tank, will help control odor. I've never tried it, as I have not had an odor problem with mine.

[InterBlog]

Originally Posted by Windowsofaspen

I have a 2016 Mercedes Galleria and everytime I drive it it smells like black water inside the unit the bathroom doesn't smell I'm not sure where the odor is coming from? If anyone has any tips or help please help. Thank you
Is there some type of valve on top of the tank?

Do you mean a Coachmen Galleria built on a Mercedes Sprinter?

It would assist your question if you could tell us the make and model of your commode that was installed (it's in your paperwork). Your issue may have less to do with the vent, and more to do with the lower plumbing. Some of us have had this type of issue on other models.

[Davydd]

Grey tank water smells pretty bad and that comes from the floor drain. You have to keep the U trap filled with water as it evaporates out or more likely jostles out from driving especially in hilly or mountainous country.

If your toilet tank holds a modicum of water it shouldn't smell unless you haven't cleaned around the toilet. Using a toilet number 1 or 2 can produce mist that lands on surrounding surfaces. If you don't use your wet bath to shower in, both these conditions can arise quickly.

The vent could be the culprit, but that is the last thing I would check.

[avanti]

Originally Posted by DUTCH in Atlanta

There's a vent up top, but no way to close it.

Try adding one of the commercial black tank additives that has odor control properties. Some folks say that Downy fabric softener, when added to the tank, will help control odor. I've never tried it, as I have not had an odor problem with mine.

I disagree.
The LAST thing you would want to do is to close the roof vent. It is there to prevent odor problems, it does not cause them.

A properly-operating sewage system (in your van or in your house) will not smell. If yours does, either you have dry traps or there is a leak. No magic additive will fix the problem. You need to track it down and fix it. Your holding tanks do not need additives. They are palliative at best.

[avanti]

Originally Posted by DUTCH in Atlanta

Did I advise closing the roof vent? Please try to read my response without getting your ego and emotions in the way! Thanks.

Originally Posted by DUTCH in Atlanta

There's a vent up top, but no way to close it.

Please consider taking responsibility for what is plausibly inferred from your choice of words and not just their literal meaning.

And, please consider refraining from responding to an attack on an idea with an attack on a person.

[Davydd]

Originally Posted by Windowsofaspen

I have a 2016 Mercedes Galleria and everytime I drive it it smells like black water inside the unit the bathroom doesn't smell I'm not sure where the odor is coming from? If anyone has any tips or help please help. Thank you
Is there some type of valve on top of the tank?

I see you have a run on sentence that confused me. I answered for inside the bathroom. Are you saying it smells while driving from where you are seated in the cab? Or are you saying it smells inside the bathroom?

Avanti is right. There is nothing you can do to mitigate the smell by dumping additives in the tank. That's like running a marathon and putting on under arm deodorant.

[InterBlog]

OP has not yet responded re: his equipment. I have no idea what model of pottie his manufacturer is using. That is an important question.

For the benefit of others who may be interested in this question, some of us have had big trouble with certain models of toilets, especially Thetford. A small and carefully-curated collection of horror stories:

(1) The Roadtrek Life account here (note that this is the venerated DIYer, not the Wendlands).

(2) My account here.

(3) ClassBWarned's account here.

Notably, even though my husband and I upgraded our toilet, our problems still have not gone totally away. They are not as bad as they were with the Thetford, with it's horrific, unconscionable design.

But I still don't have adequate venting. We modified our vent line and upgraded our roof vent to one of those that is supposed to be better at pulling negative pressure via Bernoulli-type effect. As far as I can tell, the only way we can improve further is if we install an active vent (12 volt fan in it) rather than a passive vent. And the last time I checked, there were no longer any of those on the market that were reliable. Edit: And we have not yet prioritized the building of one ourselves (a few owners have done this). Too many other van mods have been in our queue.

[Phoebe3]

If the OP's Galleria has the same toilet as the Crossfit/Beyond, it is the Thetford Aqua Magic STYLE II.

[GallenH]

Getting some bathroom oder. Have visited the other threads in this blog on this. Can't seem to pinpoint it. Smelling around the base, I can't detect an odor. It's strongest when I open the lid to the bowl. Bowl holds water so it seems improbable that it's a faulty flapper seal. Not sure if odor can get in
where flush water inlet is.

Thetford Aqua Magic IV. I know, I've read about junk splattering into the body.
Went down into the post-flapper region with a tire brush. Cleaned up some. Didn't help odor.

Vent. My RV often sits under trees in the shade. Desert trees typically have very fine leaves (1/4" and smaller) that drop continuously. My vent tube is open at top. Can stuff plug that tube? Has anyone ever "cleaned" that. Perhaps with compressed air from the top?

Advice ALWAYS welcome!

thx.glenn

[peteco]

Roof vent: I have never cleaned mine but I did put an aluminum screen on top to prevent debris, especially acorns, from dropping in. I was concerned an acorn could damage the macerator impeller.

Traps: the water in the traps can evaporate. The smell from the gray tank can be bad like the black tank. Fill the trap occasionally with water or RV antifreeze.

Black tank: I try not to leave waste in there when I am not using the vehicle for a while. I recently had a smell and realized I had not emptied and flushed the tank since our last trip, where we did not use the toilet much. I installed one of the tank sprayer fittings in the tank. This sprays water all over the tank and helps get more of the waste off the walls. I find I have to do several spray and drain sequences to get the water coming out reasonably clean.

Gray tank: I am considering adding a tank spray fitting like I did on the black tank. Otherwise I should do more fill, drive, and drain cycles than I presently do.

Toilet: yes the Thetford design is nasty inside. I have cleaned the inside once and the stuff is really hard to remove.

Overall I do not have any major smell issues when I do all of the above, though occasionally a minor smell issue.

[GallenH]

Roof vent: Yes, regardless of the source I really need to do something like you've done to keep stuff from getting in the vents. Were yours originally just the pipe sticking up through the roof? How did you make the cover?

Traps: That was the first thing I did; fill all the traps on the sinks and shower with water.

Tank sprayers. Didn't know that was something you could add. Heard of them on As. Where do you source them?

Toilet: You mentioned that you did clean once. Did you eventually replace? I've thought about just pulling it, cleaning and replacing seals parts. It has been in the RV since new without anything being done to it. That's 22 years.

Perhaps it's cheaper just to buy a new one. Thetford claims the toilet has been "newly redesigned" on their site. Anyone know what that means? The IV is no longer available. Only the V.....plus some others including ones with china bowls.

Thx, peteco.

[InterBlog]

Originally Posted by GallenH

... Thetford claims the toilet has been "newly redesigned" on their site. Anyone know what that means? .....

Nope. I did not see any such auspicious claim here. (Edit clarification: They do use the word "redesigned" but in the context of flush, not construction. There never was anything wrong with the flush - it was the construction that caused so many problems.)

Note that the porcelain bowl varieties are no less notorious for their inability to be air or water tight. They tend to develop leaks at the seam between the china and plastic.

I searched high and low for a higher-quality model. Nothing would fit in our wet bath. By the time we get up in price and quality, they assume that you are macerating and conveying to a remote waste tank (like on a sailing vessel). There's nothing "higher end" in the way of gravity toilets.

[peteco]

Originally Posted by GallenH

Roof vent: Yes, regardless of the source I really need to do something like you've done to keep stuff from getting in the vents. Were yours originally just the pipe sticking up through the roof? How did you make the cover?

Tank sprayers. Didn't know that was something you could add. Heard of them on As. Where do you source them?

Toilet: You mentioned that you did clean once. Did you eventually replace? I've thought about just pulling it, cleaning and replacing seals parts. It has been in the RV since new without anything being done to it. That's 22 years.

Perhaps it's cheaper just to buy a new one. Thetford claims the toilet has been "newly redesigned" on their site. Anyone know what that means? The IV is no longer available. Only the V.....plus some others including ones with china bowls.

Thx, peteco.

I made the vent screen out of some perforated aluminum sheet I had in my scrap pile. The holes are about 1/8". You could make something like it by drilling holes in aluminum sheet, or find something similar to use. I screwed it down with two aluminum screws.

Tank sprayer:
https://www.amazon.com/Camco-40126-T...94885142&psc=1

Toilet is original Thetford, 13 years old. If I replace I might get a Dometic as I think it has less area for crud to buildup inside the toilet. If yours is 22 years old i would replace rather than rebuild.

[GallenH]

Interblog: One would think that with both the RV and marine market that it would be a profitable market for some company to secure. Wonder what they put in "high end" Bs....and Cs....and As? Anyways, I saw your extensive post on your blog earlier and
can't remember if you ever found a way to have your feet reach the ground. Hate to be airborn too long. I'll have to check Dometic dimensions to see if one will fit in my old PW.

best.glenn

[GallenH]

Peteco: Looks good. Your pipe must be larger or there's a couple on the end? Mine is only 1.5" But it would be easy to get a 1.5->2 adapter on mine to give it more surface
area. It looks like a good solution where I wouldn't have to mount via screws something on the fiberglass roof.

Re the toilet: Yeah, I was thinking the same thing about replacing vs. rebuilding. Still would like to check the vent line, though. Maybe someone will respond who's cleaned out theirs.

glenn

[markopolo]

There's an overflow hole right where fresh water enters the toilet bowl on some Thetford toilets. That hole connects to a drain tube that also functions as a P-trap to stop odors.

If there's no water in that tube then odors have a direct path in.

Try adding water to the hole/tube to see if that helps. It's possible that the tube is cracked or has come off.

[GallenH]

You're right. I hadn't thought of that but I looked at the parts diagram for the Thetford toilet that I have and there is an overflow tube clearly bent in the shape of a trap. Ok, I'll go out and put some water in it; wait for a few hours and check it out.

thx.glenn

[Doneworking]

peteco mentioned checking the gray as well as the black. I don't know about PW, but RTs have an aisle shower in many models and if not used and kept sealed, smellies can sure come up through there as well.

Filling black and gray with water and adding a whole lot of Dawn dishing washing soap seems to help as well. Drive around in town with stop and go driving and it slushing in a few miles, let it set for a few days and dump and flush. That is how I sometimes do it.

We have kept our 2007 RT in the third garage at our house for a lot of years and never had an odor concern at all. You would think it would vent into the garage, but it never has smelled. Maybe just dumb luck.

[peteco]

Originally Posted by Doneworking

peteco mentioned checking the gray as well as the black. I don't know about PW, but RTs have an aisle shower in many models and if not used and kept sealed, smellies can sure come up through there as well.

On my 210 we never use the hall shower, just the enclosed shower. I had some sewer odor coming from underneath the vehicle. I went underneath and found the aisle floor trap attachment to the drain was messed up. It was hard to work on so after a while I gave up and sealed the aisle floor drain. No more odor problems coming from that source. Since then I have had some small leaks in my Sanicon hose that have caused a smell, but those have been easy to fix.