Sewer Smells

[tnmotonana]

We are new to motorhoming and need to hear from the experts! We have had a pull behind for years.
So my question....When we dump the smell is horrible inside the coach. I dont know if we are doing or not doing something right. We use the tabs/or liquid while parked and smell nothing, but the minute we dump the black tank it will almost make you sick. Please help

[boston_blacky]

'Good to Go' says Hemi RT! I just installed a new roof vent; i.e. 360 degree swivel type. I'll see if this improves matters. BB

[Hemi_RT]

If you are running water into the toilet/tank when it is being dumped this is where your smell is coming from. Don't do this and you shouldn't have the smell, leave some water in the bowl while it is being dumped. Also use a GOOD tank chemical all the time and you should be good to go.

[carringb]

coolmom42 wrote:

carringb wrote:
This happens to me, and I realized its from the water getting sucked out of sink trap in the kitchen. I don't have a permanent solution, other than I immediately run the water and add some lemon tank deodorizer, and this does fix it, be does't prevent it the next time I dump the tanks.

You should have an air admittance valve in the drain line between the sink P-trap and the gray tank. They are usually under the sink. It's a little device that sticks up about 3" from the drain line. The purpose is to allow air into the line so the water doesn't get sucked out of the sink trap. But it shouldn't let odors from the line back into the RV.

If you don't have one of these, (but you should) or it isn't working correctly, that's why the water is being sucked out of your trap allowing the odor inside.

I do have something that looks like that. I've been wondering exactly what and how it works. It does effectively stop the sink from draining when the tank is full so it doesn't back up into the shower (my old Jayco's tub was basically overflow for the sink... Yuk!).

On that note.... it seem to work this morning after I dumped the tanks. I'm stumped....

[SteveM1990]

I've used 2 or 3 bags of ice into an empty black tank to clean. This slides around and scrubs the insides.

Works best on short journeys with corners or start-stop traffic.

I guess it could damage the level sensors if they're a protruding type, but I haven't found that to be the case with mine.

Steve

[coolmom42]

carringb wrote:
This happens to me, and I realized its from the water getting sucked out of sink trap in the kitchen. I don't have a permanent solution, other than I immediately run the water and add some lemon tank deodorizer, and this does fix it, be does't prevent it the next time I dump the tanks.

You should have an air admittance valve in the drain line between the sink P-trap and the gray tank. They are usually under the sink. It's a little device that sticks up about 3" from the drain line. The purpose is to allow air into the line so the water doesn't get sucked out of the sink trap. But it shouldn't let odors from the line back into the RV.

If you don't have one of these, (but you should) or it isn't working correctly, that's why the water is being sucked out of your trap allowing the odor inside.

[GMandJM]

That's a hard-earned picture! Really nice.

[Wishbone51]

GMandJM wrote:
In your signature picture it looks like your camper has a big rock instead of tires. Did you "re-invent the wheel"? Very cool picture!

Thanks! I took that at Yellowstone, one of my stops on my Portland (OR) to NYC trip a few years ago. Climbed a hill to take that picture, and sprained my ankle really bad on the way down 🙂

[GMandJM]

Wishbone51 wrote:
I've been lucky I guess. I don't seem to have any smells, even if there's no water in the bowl. I'm pretty anal (pun intended) about rinsing my tank. Maybe that's the reason.

Haha! Good one.

In your signature picture it looks like your camper has a big rock instead of tires. Did you "re-invent the wheel"? Very cool picture!

[Wishbone51]

I've been lucky I guess. I don't seem to have any smells, even if there's no water in the bowl. I'm pretty anal (pun intended) about rinsing my tank. Maybe that's the reason.

[carringb]

This happens to me, and I realized its from the water getting sucked out of sink trap in the kitchen. I don't have a permanent solution, other than I immediately run the water and add some lemon tank deodorizer, and this does fix it, be does't prevent it the next time I dump the tanks.

[klutchdust]

Had the same problem, made this to fit garden hose, insert way down into tank, a few drops of dawn dish soap and the smell is gone. The end is bent over and 2 -3/16 holes drilled into it

[GMandJM]

If you are dumping your black tank without having water in the toilet bowl, you are essentially turning your toilet and camper into a vent system for the campground's sewer system.

Make sure the black tank dump gate/valve is CLOSED before you flush the toilet during your dumping procedure.

[lanerd]

Yes, you do need to change your procedure. Never open the toilet while dumping as that will act as a vent for the vapors. Always keep water in the toilet bowl at all times. When flushing the toilet, do it quickly...very quickly, and then put about a quart of water back into the bowl.

FWIW...you don't need any chemical additive to contain odors. If you have an odor, you have a problem that needs to be addressed either with a repair or procedure. All chemicals do is mask the odor...doesn't fix it.

After dumping, put at least two or three gallons back into the tank. If you will be traveling after you dump, put in a cup of your favorite laundry detergent and it will slosh around in the tank and act as a cleaning agent. When you set up for the night, fill the tank with fresh water and then dump, flushing out all the soap and stuff. Add a couple of gallons back into the tank prior to using it again.

Others have reported great success in adding Calgon water softener to the tank along with the laundry detergent that supposedly will coat the inside of the tank and make it slippery. Sounds logical.

With rv black tanks....water (lots of water) is your friend.

Ron

[Halibut214]

Old-Biscuit wrote:


If water doesn't stay in toilet bowl you should be having odors from black tank all the time......not just when dumping.

Not necessarily. When you lift the lid at the dump station you are more times than not greeted with gas. The gas rises up through the hose, into the holding tank, through the bad seal and right up your nose.