Smells for a few minutes after dumping black tank

[Seabee]

I started using a "Y" connector this trip to hook both sewage hoses together so I could leave the front gray tank open and not have to crawl under the slide to empty it. When I emptied the black tank for the first time I got a bit of smell inside the camper. It only lasted a few minutes but was there none the less. I figured the smell had somehow come through the open front gray tank valve. So for the second dumping of the black tank I closed the front gray first but still got the smell. I did not have this smell before I started using that "Y". Any ideas on what could be happening?

[14george]

Are you flushing your hoses out or is air vents open letting smell dray back into your camper

[Seabee]

Are you flushing your hoses out or is air vents open letting smell dray back into your camper

I'm flushing the hoses.

[Javi]

I'm thinkin' that you are leaving the hose in the sewer hole and with a valve open the stink is being pulled up the hose by the vent on top of the trailer..

I learned a good while ago that even at full hookup sites it is less smelly to only open the tank valves to dump the tanks.. Yes it is a bit of an inconvenient, but better than smelling the sewer..

[hankaye]

Howdy All;

I leave my kitchen gray open until it's time to dump. After I
do my weekly chore, I get some odor in the RV for a short time.
The main reason, best I can figure is that I get some from the
roof vents (tanks), into the overhead vents(14"X14"), as the 2
are fairly close together. I take Rascal for his afternoon walk and
ball chase and when we get back, just smell I the Downey I dump
in the tanks.
Here's my full routine;
The kitchen gets closed while the black is being dumped, water is
shut off (I usually open the tap to full before I head out the door to do
the chore), and re-directed to the flush system, with a 'Y' fitting and a
back-flow preventer affixed to the flush hose (no flow to kitchen at this
time). Then after I'm finished with the Black tank, I switch the water back
to the RV at the 'Y' and while the Bath Gray is emptying the kitchen is
filling ... when the Bath Gray is empty, I close that valve and "Dump the
Kitchen. Close up the skirting, put the hose away and go dump 3 cap
fulls of Downey in the commode followed with 3 bowls full of water
then off to the exercise yard for Rascal...

hankaye

[Festus2]

I learned a good while ago that even at full hookup sites it is less smelly to only open the tank valves to dump the tanks.. Yes it is a bit of an inconvenient, but better than smelling the sewer..

x2 We usually don't stay at any one place for any length of time so this routine works well for us. Dump and then leave.

[sourdough]

We leave our valves closed until it is time to dump. We try to time it when the black and either of the gray tanks is full. Tried leaving gray 1 (shower/bathroom) open all the time for a month while in FL. When I pulled the sewer hose off the entire bottom of the ribbed hose had "goo" built up in it. It had never done that when we kept the valves closed and dumped when needed. The buildup happened even tho I dumped gray 2 each time I dumped the black tank and also ran the black tank flush. It looked like a buildup of soap scum from showering. Needless to say the hose got cleaned and I don't leave it open any longer.

[Seabee]

Figured out what it was. It wasn't the black tank at all. It was the rear gray tank. When I emptied the rear gray, it was coming out with so much force it was sucking the water out of the p-traps and the smell was coming out of the bathtub and bathroom sink drains. I removed the Y-connector and ran just the one hose when I emptied the rear black and gray, and voila, no more smell. I reckon I need to put an inline valve at the Y from now on to keep this from happening again.

[mcsearch1]

I empty my tanks one at a time and close one valve before I open another. I also have had the odor problem. I found it was coming in through the ceiling vent in the bathroom. If I close the vent or keep the fan running I have no issue. This is not surprising as the black tank vent comes through the roof right next to the ceiling vent.