Toilet odor when driving

Keep the water inside the pipes, tanks, and sinks
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Mark
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Re: Toilet odor when driving

Post by Mark »

I just want to report that after a few weeks of having the new vent and having driven around with a full black tank and having the windows wide open, I am no longer getting ANY sewer smell in my rig.

If you are having this problem, cut right to the chase, order and install the weather vane vent that I’ve recommended. above.
If it ain't fun - it ain't done!
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con5
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Re: Toilet odor when driving

Post by con5 »

OK so our rig is smelling when we run the fan which we do a lot because we prefer to boondock.


When we first started doing this we noticed it smelt pretty bad like stinky tank odor.

Step1. We replaced the vent with the weather vane style (side note here: our 1998 has a combined vent from the black and gray systems), but obviously, this won't help much when the van is not moving or there is no wind.
Step 2. Started regularly cleaning the black tank with one of those wand things.
Step2. Replaced flange seal on the toilet.
Step3. Replace toilet lip seal on blade mechanism (this was a nightmare due to wrong parts in the kit but that's another story), and yes it holds water.

Still, it smells bad, better but still bad.

The smell is certainly coming from the wet bath area at the back of the van. I tried plugging the sink valve, taping the air admittance valve on the sink closed, and plugging the shower drain. Nothing seems to make much difference. After replacing the toilet seals, I am fairly certain the smell is coming from behind the fiberglass where the spare tire sits.

I'm sort of at a loss for what to do next. Any thoughts?
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Millennial Falcon
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Re: Toilet odor when driving

Post by Millennial Falcon »

con5 wrote:
Thu Jul 01, 2021 12:59 pm
I'm sort of at a loss for what to do next. Any thoughts?
The easiest fix that I did, and it solved it instantly, was to install a MaxxAir fan which has reversible airflow. So, I open a window inside (usually the window behind the couch) and set the roofmount fan to suck air in as opposed to blowing out.

Especially if your windows are closed, and you create a vacuum inside the space with an exhaust fan... it can pull air backwards through the waste tank vents. So, it could suck air from the vent, blow it over the waste-water, pull it up through a drain... and put stinky air inside the living space. Reversing the fan-flow can fix this, or opening several windows in order to prevent air being pulled from inside waste tanks. I have found it can also help to dump some water into the tub every once in awhile (especially if you never use it). Just to fill it's P-trap and prevent grey-water smell from coming up through the tub drain.
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con5
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Re: Toilet odor when driving

Post by con5 »

Millennial Falcon wrote:
Thu Jul 01, 2021 1:08 pm
The easiest fix that I did, and it solved it instantly, was to install a MaxxAir fan which has reversible airflow.
We thought about going that route but the fantastic fan works ok, especially since I installed a PWM speed controller, and we don't want to put more money into a new fan. I guess I might be able to rig up a simple switch to change the direction of the fantastic fan?

Also, I will try dumping some water into the tub drain (we never use it). Where is the p-trap for the tub, under the van somewhere?
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skater
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Re: Toilet odor when driving

Post by skater »

Is the plumbing vent pipe okay? Not clogged? Problems with that pipe can cause odors in unexpected ways.
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con5
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Re: Toilet odor when driving

Post by con5 »

skater wrote:
Thu Jul 01, 2021 6:18 pm
Is the plumbing vent pipe okay?
Well, I don't know for sure. It certainly smells stinky when I go up on the roof so I assume there is some airflow there. It is a pretty long and torturous run of pipe from the black tank vent to where it combines with the grey tank vent in the closet area before punching through the roof. I don't know why they didn't just go straight up behind the fridge to the roof !!???

I'm not sure how a water test would be very conclusive with this combined vent system. I am welcome to suggestions.
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con5
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Re: Toilet odor when driving

Post by con5 »

I went ahead and installed a reverse polarity switch into the "fantastic" fan. With the PWM speed controller I installed a few months ago we now have a "vantastic" fan. So now if it gets too stinky I just reverse the flow. Mostly we still keep it on exhaust flow but since we recently made some screens for the front windows we are not getting much tank odor. We still get some stank when we drive with the windows down but at least there is an easy solution for that.

Here is our ugly “vantastic” fan:
AB8C7AD0-7FDB-47F2-9099-15A338F208BA.jpeg
AB8C7AD0-7FDB-47F2-9099-15A338F208BA.jpeg (2.18 MiB) Viewed 3871 times
One of these days I’ll take it all apart and repaint…
silvertrooper
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Re: Toilet odor when driving

Post by silvertrooper »

I've also put the enzyme tablets/packets used in the toilet down the sink, to control odors in the gray water tank. Agreed on keeping all the traps full of water, including the terlet.
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