Yikes! Hot Day Black Tank Stinky...

[aztex]

Howdy,

 

This is the second time when weather ramped up into the 80's my black tank just reeked!

 

What I've been doing up to now is Happy Camper with a 1/2 cup of Calgon and 3/4 cup of laundry detergent. If some bleach at hand ~3/4 cup of that. Today was the worst though!

 

Oddly the Happy Camper has been miraculous is cleaning the tank. Last time and this time I filled to 80% (the stink started with 30%) and drained and following flush brought out clear with no debris, slightly tinted.. I peeked inside last time and could see clean plastic bottom of tank... SO I'm getting it clean and am baffled with the odors...

Vent must be working as the odor was stronger out side!

Any hints for an emergency odor removal? Dumping the tank seemed to work ok. I was considering a good gallon of bleach and fill tank with fresh water over night...

 

It's a new coach only 3 months of use and meticulously maintained.

 

Thanks,

 

Az Tex

[2gypsies]

Is your seal always covered with water?  Is there a smell inside all the time?  Do you have a fan running in the roof?  Try turning off the fan.  Perhaps all your concoctions along with 'stuff' are creating to the smell.  We just used plain water and never had a smell.

[sandsys]

Don't turn the vent fan on while flushing the toilet--it draws the odor into the room. Wait until completely done before opening then vent fan.

Linda

[aztex]

Just now, 2gypsies said:

Is your seal always covered with water?  Is there a smell inside all the time?  Do you have a fan running in the roof?  Try turning off the fan.  Perhaps all your concoctions along with 'stuff' are creating to the smell.  We just used plain water and never had a smell.

Seal is fine... holds water. Always has a cup or so

No smell 99.9% of the time...just today and once before when it got hot.

Fantastic Fan as needed, usually off. 

My concoctions are pretty mild but as I said a look inside down the hole looks pretty "clean"...

Seems like the odor wafted out and drifted back in via fan out let which is only ~3 feet from the vent as it was as bad or worse outside..

[chirakawa]

6 hours ago, aztex said:

Seal is fine... holds water. Always has a cup or so

No smell 99.9% of the time...just today and once before when it got hot.

Fantastic Fan as needed, usually off. 

My concoctions are pretty mild but as I said a look inside down the hole looks pretty "clean"...

Seems like the odor wafted out and drifted back in via fan out let which is only ~3 feet from the vent as it was as bad or worse outside..

Most of my rv's I never had a problem with odor.  On my last one, anytime it got good and warm, upper 80's and above, I would get a belch of nasty smell .  It's not necessarily about a bad seal or whatever.  It might be due to a poor plumbing design, but may not be also.

When it's hot out, the black tank can really get to cooking up a brew.  Most of the odor should go out the roof vent.  However, on a still day with no wind to draft the odor out of the tank, when you flush it can cause a problem.  Understand that when flushing, you have a quart or more of liquids and/or solids going into the tank.  That action requires an equal amount of gas to leave the tank.  It will generally take the path of least resistance.  The drain in the bottom of the bowl is 3", compared to the roof vent which is only 1 1/2" and is 8' or so tall.  It's only natural that some of the gas will come back up into the living space through the flush drain.

It doesn't take much of a belch to create a pretty good smell in the bathroom.  The solution, of course, is to seek cooler climates.  🙂

[Kirk W]

Are you sure that the problem is the black tank? In my experience, I have found that the gray water is often more odorous than the black and we almost never use any product of home-brew in our waste tanks, except for occasional cleaning. Remember that you wash all sorts of cooking grease, body grease, soaps, food particles, and such into the gray tank where it then sits and accumulates. The gray tank has several routes it can easily vent into the RV. If you allow the P-traps to lose their water seal the will vent inward and under each sink, there is a plumbing vent which if stuck closed will cause the P-trap to lose its water and if stuck open it will vent the tank into the RV. I suggest that you check out these possible issues.

For more about this problem, read this article.

[jpcoll01]

Kirk  hit what I was going to say.  

 

[FULLTIMEWANABE]

Kirk has a very valid point.   Grey can really hum over time of crud collection, but you say your coach is only 3 months old = hmmmm.    Just a thought but the vent, does it have a swivel on top to move as wind changes direction?  OR, is the pipe disconnected lower down in the wall???     We had similar on our unit many, many years ago when new and discovered that our vent pipe wasn't sealed properly within the wall.   We replaced upper piece with swivel on top that rotates as per the wind and never had issues since.  

Like 2Gypsies we use water only, unless boondocking for more than 2 weeks at a time in higher temps, then will add some masking odourizer (better to empty more often and black flush tank though than use that we've found!).

Also check for any leaks (shower, sinks and toilet drainage) at any areas where there is a joint/connection/fixing - it's amazing where things can escape from if not properly sealed. 

[rynosback]

8 hours ago, Kirk W said:

Are you sure that the problem is the black tank? In my experience, I have found that the gray water is often more odorous than the black and we almost never use any product of home-brew in our waste tanks, except for occasional cleaning. Remember that you wash all sorts of cooking grease, body grease, soaps, food particles, and such into the gray tank where it then sits and accumulates. The gray tank has several routes it can easily vent into the RV. If you allow the P-traps to lose their water seal the will vent inward and under each sink, there is a plumbing vent which if stuck closed will cause the P-trap to lose its water and if stuck open it will vent the tank into the RV. I suggest that you check out these possible issues.

For more about this problem, read this article.

I had a gray tank vent go bad.

[Barbaraok]

aztex

Where was the odor and when did you smell it?  

There will be a slight order when you begin dumping as the contents of the black tank hit that pocket of air as they enter the sewer system.   It doesn't last long, and on really warm days you will smell it a little more.   But it should quickly dissipate as the tank contents continue down the sewer.   

Now if we are talking about odor when you flush, depending upon things like how full you fill the bowl with EXTRA WATER (you do that, right) before you flush and how hot it is, you may again get a fleeting 'sewer' smell which will quickly go away as water flows down.  Or, if the odor comes down (in) from an open window/vent in the area, then you need to look at the vent for the tank.   We use a swivel vane on top of the vents for both tanks and in most cases never have any smells.  

 

[rynosback]

You could also change your diet....😉

[ms60ocb]

From prior advise I suspected the Grey Tank just a couple weeks ago. I tried a couple of the items listed above, I really thought filling the Grey tank by doing the laundry  and taking long showers and flushing would help. But the Grey water was not the problem.

I found the toilet seal at the base of the toilet to be leaking gas.  When I lifted the toilet off the floor the old  (approx 3 1/2 years old) seal fell in pieces to the floor. Installed a new wax seal and my problem solved.

Clay  2016 DRV MS 38PS3

[jean_rockyroad]

To get rid of odor, we use the washing soda trick: we put it down the shower drain now and then as well as the kitchen sink drain. I just empty a packet of it into the sink or shower base and pour hot water over it when the waste tanks are empty. Out comes lots of gunk the next time we empty the tanks.

[FL-JOE]

You could have a removable black water tank and have it steamed cleaned every week and it will still have odors if you are making regular deposits in it.  Really there is only two things that can cause you to get black tank odors inside your RV.

1.  Your roof top vent is plugged or if it is working you are pulling odors from it back into the RV.

2.  Either your black tank has a crack/hole in it or some pipe, seal, or connection is bad.

I agree with others that gray tank odors can occur but you should be able to tell the difference.

[Ray,IN]

Dave said it first,

The key to preventing/reducing black tank odors is WATER!  Add enough water to the black tank to insure all solids are completely covered. Remember your black tank is a holding tank only, if there is not adequate water you are inviting the consequences.

[chirakawa]

2 hours ago, Ray,IN said:

 

Add enough water to the black tank to insure all solids are completely covered.

If your turds don't float, you aren't eating enough fiber.

[Barbaraok]

There’s a difference between solids in toilet bowl and after 1 day in holding tank.  Water is the universal solvent, and floaters actually disintegrate rather quickly.  Dense material sinks and covered with water, disintegrate over A slightly longer period of time.  Either way, WATER, and a sufficient amount, is what is needed. 😉

[chirakawa]

3 hours ago, Barbaraok said:

There’s a difference between solids in toilet bowl and after 1 day in holding tank.  Water is the universal solvent, and floaters actually disintegrate rather quickly.  Dense material sinks and covered with water, disintegrate over A slightly longer period of time.  Either way, WATER, and a sufficient amount, is what is needed. 😉

I totally agree that lot's of water is very important in the black tank.  However, you can't put enough water in the tank to prevent odors from breaking the surface. 

[RV_]

I agree with all the above about only needing water. Especially not getting concerned if you only get a whiff on flushing. However for odors that persist there can be two other culprits. One is the black and gray tank vent tubes themselves. If the factory worker had a hangover he may have pushed your vent pipe down all the way to the bottom so no gas can escape but a tiny amount. This can cause a burp every time you flush but that isn't always diagnostic.

Another member here was down in Cabo and only got black water odors when the Air Conditioner was on. I had just sealed my Air unit's sheet metal as there were all kinds of screw holes in it that were not taped up. He went up, removed the shroud, found the same thing and using duct tape patched the holes and sealed the seams and voila' no more odors when the A/C was running. Your home toilet has a pea trap builkt in sealing gases and odors from under the toilet out while flushing. ON RVs it is a straight shot with no water seal so there will always be an odor from the tank from flushing briefly.

If all the other ways to get odors aren't your issue try checking those.

Oh forgot another. Check that dirt daubers have not blocked the vent with a giant mud nest or a bird made one in the vent. You can test it by running a piece of wood trim down it or running a hose from the top and see if the water goes through as fast as it should for that diameter pipe. (don't run the hose down to the tank, just fill the tube from above to see if it is obstructed)

Safe pooping from odors!

[sandsys]

Um, I don't think any of us have asked if you leave your dump hose attached. If so, it could be the problem.

Linda

[Roadtrek 1]

3 hours ago, sandsys said:

Um, I don't think any of us have asked if you leave your dump hose attached. If so, it could be the problem.

Linda

Linda, my dump hose is permanently attached.  It's designed this way and it would only be removed to replace the entire unit.  I had a hose crack early on and it was replaced.. I realize that many people have to attach and remove their dump hose each time it's used, but, mine is always connected. 

Thankfully, I don't have a current problem, but, I had a rotten eggs smell in my water and used a product called Purogene to get rid of it. It took very little product and was effective immediately.   Just sharing this with all of you. 

My problem occurred during the hot summer months.. Maybe it's in your black, grey or fresh water tank?   

If you can't figure out where the source is, but my problem was in the fresh water...

Good luck.

https://www.amazon.com/Treatment-Concentrate-Preparedness-Treatment-Concentrated/dp/B07B68XLCG

[Kirk W]

13 hours ago, RV_ said:

One is the black and gray tank vent tubes themselves.

Since the RV involved is pretty nearly new, this would be high on my priority list of things to check. After a career of repairing things, I will always look to the least difficult possibility first which is my reasoning on the plumbing vents but this issue is not terribly difficult to check as well and happens more often than it should. The vent pipe can sometimes be too long and extend down into the tank too far, or it can also not reach high enough into the vent cap on the roof. I have even seen at least one case where both problems existed because the pipe was not well anchored in the wall or sealed to the tank top and the pipe actually slipped down during the early travels to cause both problems. The result was that odors didn't reach the vent cap and the tank wasn't vented if the level in it reached withing about 6" of the tank top.