Sewer Smell

[Martinez]

Just went on our first trip with our 2017 toy hauler. While camping our neighbor told me not to leave the valves open for the black and grey tanks. Said the wste will stick and stink. Well now that we're on the road it stinks so bad in the rv. Any thoughts?

[Popfla]

You should never leave the black water valve open, or you definitely will get sewer gas/odors inside the RV. You'll also get much better emptying by letting the tank fill and only emptying it when it is nearly full, but definitely empty it before leaving the last campground of your trip.
Similarly with the grey tank. Personally, I leave it closed until it needs emptying, and you want to use the grey water to flush the sewer hose after you empty the black tank. It is possible to leave it open if you form a trap in the sewer hose to keep fumes from entering the RV.
And lastly, if you leave both valves open at the same time, you risk having 💩 backfilling into your grey tank.

[Bob Denman]

Are you leaving the overhead vent in the bathroom open, while driving?
That can often end up drawing gases up out of the blackwater tank (via the toilet), and into the RV...

[The_Breeze]

Originally Posted by Martinez

Just went on our first trip with our 2017 toy hauler. While camping our neighbor told me not to leave the valves open for the black and grey tanks. Said the wste will stick and stink. Well now that we're on the road it stinks so bad in the rv. Any thoughts?

Well, this problem stinks to high heaven.

Did you dump before you departed? If you left the waste in the sink, make sure to put the drain stop in to keep the grey vapors from backing up into bathroom and escaping through cracks (e.g. top and bottom of door).

As for the black, a lot of folks use a Camco Cyclone type vent cap to pull the sewer smell out of the black tank as they travel.

As for being stationary, yes - do not leave the valves open. The toilet waste will tend to pyramid, become nearly fossilized and you'll never get rid of it without having it power steam cleaned. If you already have this build up, then a toilet wand may help to exit the built up waste. Don't count on your black tank flush to do it. A 20yr full-timer told me about 4 'scoops' or a cup of Zinc Sulfate (think fertilizer) will deodorize and help breakdown the waste. If that's not your style, they sell special chemicals you put down the toilet after you dump.

Keep us posted and let us know what you decide to do.

[halfprice]

also check your air admittance valve. Should have one under the kitchen sink and one in bath vanity. If they are loose you will get smell

[mountainsam]

After emptying at the camp ground before hitting the road I like to add about 5 gals of water to the black tank and let it slosh around as I drive to the next camp ground or dumping station before arriving home. Some folks even add a little Blue Dawn to help clean things up. And as stated by others, keep the drain closed in the sink, many rv bathroom sinks drain into the black tank. Happy Travels

[16ACE27]

Originally Posted by Bob Denman

Are you leaving the overhead vent in the bathroom open, while driving?
That can often end up drawing gases up out of the blackwater tank (via the toilet), and into the RV...

Shouldn't be coming out of the toilet if a water seal is left on it, BUT:

Generally there is a heater vent in the bathroom
Generally there is a heater vent in the wet bay
If you have any stink in your wet bay it is easily drawn through the joined heater vents into the coach, especially if you are drawing a vacuum by leaving any roof vent open while driving.

[The Gritz Carlton]

Also, and something often forgotten/delayed, did you add chemicals back to the tanks with a little water after you emptied them? I always add a little chemical to the gray tank also. Make sure you run a little water in your sinks as well. Often, the vacuum from emptying tanks will pull the water from your P Traps, leaving them empty allowing fumes back up the pipes. There's also some type of anti-back flow vent under the sinks that you can adjust. Not sure of them but the factory service adjusted/replaced mine and have no more smelly issues since.

[JamieGeek]

I do hope you are not driving with the gate valves open !

[Miramar Owner]

I have found it is best to never travel with a full black tank and to always close the roof vents when heading out.

I did have a problem with sewer odors in the bedroom one time. My Miramar has washer/drier set up in the bedroom. I took everything from the closet and removed the panel on the back wall. That's when I discovered the stand pipe for the washer was missing its cap. When driving with full tanks from one camp site to the next it forced odor through that pipe.

I temporarily duct taped the pipe...problem solved.

Good luck on solving yours.

[TurnerFam]

you listened to your 'neighbor' ??

[TurnerFam]

I always take anything anyone says, without me first asking their opinion, with a BIG grain of salt - meaning, I don't believe them and carry on just as I always have.

...some folks just think that 'telling' you things they think they know is somehow important for you, their 'neighbor', to know, when in fact, they themselves may have only 'heard' it from someone else, with no facts or real reasons for it to otherwise be 'true'. Just because others say that you should do it, doesn't make it something you should do.

[Popfla]

Originally Posted by TurnerFam

you listened to your 'neighbor' ??

In this case, the "neighbor" was 100% spot on when he/she saw that the OP had both valves open. Not only are sewer gases stinky, they can be dangerous and unhealthy when they build up inside the confined space of an RV.


Ever seen a methane explosion ?

https://www.youtube.com/watch?v=0QV1zR9kIM0

[The Gritz Carlton]

Depends on what the 'neighbor' says. They are RVers also and I first would assume they speak with experience. Qualify their advice but don't just shun it because you didn't think of it first or haven't had first hand experience with it yet. There's tons of excellent advice on this forum...there's also tons of opinions based on what one may think is logical. The greatest benefit of this forum is the fact that, whatever subject comes up, we will eventually have a plethora of "knowledge AND opinions" to choose from. The truth always will surface in anything you do.

[K0LCB]

I always leave black tank valve closed until ready to dump. I use Happy Camper to help with odor. I usually leave grey tank closed until a couple days before ready to dump. Bu I’m still learning, I’ve only had RVs since 1976.

[The_Breeze]

Sewer rats are another one of our furry little friends from the animal kingdom we'd much rather not become friends with.

I wish I could find that vid again. Beattie little eyes staring back at you through the RV's toilet drain. We won't go into how they got it out.

[The Gritz Carlton]

Originally Posted by TheBreeze

Sewer rats are another one of our furry little friends from the animal kingdom we'd much rather not become friends with.

I wish I could find that vid again. Beattie little eyes staring back at you through the RV's toilet drain. We won't go into how they got it out.

And roaches, etc. Keep em closed, fill tanks up, then dump...repeat!

[climberbob]

We had a problem with smell and it was coming from our shower drain. Fill all you drains before leaving.

[roy stone]

POPFLA's 3/15/2019 5:24 PM post is sound, good advice and SOP for waste water hook-ups. Follow it and you can't go wrong. Don't forget to keep cleaner/deodorizer in your tanks also.

[Pittstop]

After emptying and flushing our black tank at the site, we always add a bag (or two) or ice into the tank thru the toilet for the drive home (or to next site). The sloshing of the ice while driving down the road will loosen things up and the ice melts to keep a small amount of water in the tank. By the time we're home (or the next site) - we add the deodorizer chemicals for storage.