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Bathroom stench after flush and chemicals

kyonu
Explorer
Explorer
I'm sure this has been a topic many and far, but I have to ask again as many of the issues I've seen regarding this weren't completely answered. But...

With my recent purchase of my new Class C RV, the previous owner left a holding "pyramid" (to put it lightly) that we could smell every so often when using the bathroom (primarily when we flushed, letting up all the stench).

Well, I did a thorough flush, which involved a high-powered nozzle on the hose, through the open window, directly into the toilet (since we don't have a dedicated flush valve). After about an hour of filling the tank and flushing it out, blasting etc, the water finally came out clear!

As an added bonus, the holding tank meter always showed "2/3 full", and after the deep flush it was showing empty, meaning we got out a lot of what was in there.

I added chemicals per instruction (1 bottle of chemicals = 40g tank cleaning), with water as per instruction as well. (it is a 40g tank)

That night, the same stench from before returned like a phantom. It was horrible, but we had not used the bathroom since we flushed it and chemicalized it. The tank still showed empty.

Any earthly idea as to why it would still be stinking? It comes and goes, so I know it's not burned into the walls. We open the vent, close the door (toilet is sealed off with it's own door and room) and after 5 minutes it doesn't smell anymore. an hour later, a stink bomb comes back and we repeat step 1.

ANY ideas whats going on? Tips, suggestions? I am knew at this but willing to try anything. I scouted the bathroom, took out the toilet and wall fixtures and there doesn't seem to be any issues. The stink comes in regardless if we're flushing the toilet (yes, there is about an inch or two of water in the toilet as a "stink barrier" per recommendations I looked at before.)

Please help! (and thanks!)
31 REPLIES 31

Bumpyroad
Explorer
Explorer
Bobbo wrote:
Ramair wrote:
http://www.uniquedistributing.com/product_info.php?products_id=94

I have used this and its the best for controlling odors and when dumping everything is liquid. It claims it will remove the poop pyramid with 24 hrs.

http://www.uniquedistributing.com/product_info.php?products_id=94

Made clicky


at $19 a quart it better work.
bumpy

Jim_Shoe
Explorer
Explorer
Check this first, before you spend money. If your toilet has two foot pedals, one opens the opening to the holding tank and one pumps water into the toilet to flush. After stepping on both pedals to flush and then releasing them, only push the pedal that lets water into the bowl. A couple of inches will keep the fumes from rising up into the bathroom. That may not be the problem, but if that's what's happening, its a free fix.
Retired and visiting as much of this beautiful country as I can.

Bobbo
Explorer II
Explorer II
Ramair wrote:
http://www.uniquedistributing.com/product_info.php?products_id=94

I have used this and its the best for controlling odors and when dumping everything is liquid. It claims it will remove the poop pyramid with 24 hrs.

http://www.uniquedistributing.com/product_info.php?products_id=94

Made clicky
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

Ramair
Explorer
Explorer
http://www.uniquedistributing.com/product_info.php?products_id=94

I have used this and its the best for controlling odors and when dumping everything is liquid. It claims it will remove the poop pyramid with 24 hrs.
Andrew & Donna Reyes
2012 Georgetown 378 XL

hershey
Explorer
Explorer
Does the toilet hold water between flushes? If it doesn't, then the odor will seep upwards and cause the bathroom to smell. And for goodness sakes, quit using chemicals. Your just adding yet another smell to the tank. 10 years of fulltime and never used any chemicals. Only time we ever get a smell is when the toilet seal fails to hold water in the toilet. Then its time to add some vinegar to the toilet and let sit, it removes the calcium.
hershey - albuquerque, nm
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rvdudes2
Explorer
Explorer
Despite diligently and thoroughly cleaning our black tank we had the exact same stinky problem until we installed our Cyclone Sewer Vent. We haven't had any problems since.......
2005 Ford F350 Dually, Crew Cab
2009 Fleetwood Terry
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Pangaea_Ron
Explorer
Explorer
Remove the cap for the roof vent, as others have said, the vent line could be blocked, but don't do what I did.

I placed a ladder beside the MH reached over and removed the cap. When it was removed, I could see that a wasp nest was blocking the vent, so I reached in and grabbed it with my bare fingers (without thinking). Fortunately the wasps were slow to react, and I was able to retreat down the ladder. I had the visual of me laying on my back in the driveway, bleeding, with the ladder toppled over me, and being stung by wasps.

A bit of wasp spray later, and a thorough cleaning, the smells were gone. I also installed a Venturi rotating vent cap to increase the draw.
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CaLBaR
Explorer
Explorer
jplante4 wrote:
kyonu wrote:
Thanks everyone for your quick responses! I will definitely check the AAV under the bathroom sink.

The smell only occurs in this space. It's worse with the lid open, and we typically will not smell it unless we open the door (as shown in the pic). If it's NOT the AAV, how should I go about cleaning the vent pipe?

Thanks again!


Climb up on the roof with a running water hose and stick it down the vent. If it's plugged, it will fill up and overflow. Jam the hose in as far as it will go, jiggle is around and when the vent drains you're done.

Yeah, you can do it with a snake, but this is much more fun. And you already have a hose, probably not a snake.


I had the exact same problem with the smell and did the hose water trick and voila no more stink. This is easy to do and if the smell is still there look further.
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txdutt
Explorer
Explorer
buy a flushking connector & backflush your tank since you don't have a flush fitting, you may have gotten rid of the "pyramid" but there's probably lord knows what still in there (yecchhh!!)
---another thing to try are enzymes---you can get them at any rv supply place--Rid-X might do the exact same thing---fill your black tank at least half full & put a few enzyme packets in there & let it sit for at least 24 hours & then dump/flush it out
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coolmom42
Explorer II
Explorer II
Are you 100% sure you got rid of the pyramid?
Single empty-nester in Middle TN, sometimes with a friend or grandchild on board

352
Explorer
Explorer
More fiber ???????????????????????
The manatees of Halls river Homosassa Springs Fl

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salem
Explorer
Explorer
Thanks for posting the photo.

Old-Biscuit
Explorer III
Explorer III
salem wrote:
Do all models have an Air Admittance Valve under the sink? I don't recall ever seeing one under mine, either kitchen or bathroom.


All.......No

Most....Yes (very common)

They are used to keep 'P' traps on sinks from getting sucked dry when draining grey tanks.

They are downstream of sink 'P' traps on a short stub pipe.


Is it time for your medication or mine?


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salem
Explorer
Explorer
Do all models have an Air Admittance Valve under the sink? I don't recall ever seeing one under mine, either kitchen or bathroom.