WOW! What a stench - almost gassed us out!

[Mike_LeClair]

Hello All!

Admittedly, I am not the sharpest knife in the kitchen drawer. Also, the entire topic of back flow prevention valves and the mysteries of the poop/holding tank stacks completely escape me. If some of you would care to 'splain all of these things to me I would be grateful. Please type really slow cause I can't read too fast!:B

Here is the need for my query:
Last week the black tank back flusher crapped out and does not spin at all - at least AFAIK. I used the search function and found a couple of solutions that seemed to revolve around a anti-drain back "thingy" under the sink in the bathroom?

Tonight we had water back up the pipe under the galley sink and when I looked under there it was evident that the water was coming up through the vertical black stand pipe just behind the actual sink drains. There was a cap on this stand that was apparently loose and when I examined it I found that it had a spring loaded rubber stopper in the top portion of the cap. I screwed this cap thing back into the stand pipe, hand tight, yet tight. I then went out and pulled the drain for the galley tank.

Then into the bathroom to search for the ambiguous anti drain back thingy. I found this funky looking device with two pex pipes running into it which I assumed was the thingy that I was looking for. I removed it from the two pex pipes supplying it, examined it, scratched my head and other anatomical parts and immediately put it back together because I didn't have a clue what it was or did.

By the time I got back into the galley to finish cleaning up the mess on the floor from the standing pipe spill over the stench was enough to almost knock both the bride and I out cold. The dog was at the exit door scratching for all he was worth to get out. I opened windows and turned on the fan in the bathroom and the stench eventually dissipated although even now there is a residual odor that is not very pleasant.

So, then, can y'all please explain to me, in simple language, how all of this works? What did I do wrong, or to cause this most foul odor event and how do we prevent the smell and the water overflow in the future? Also, how does all of this internal plumbing somehow relate to the black tank back flusher?

Thanks for reading and hopefully responding!

Cheers!

Mike and Carol

[byronlj]

Your gray water tank hooked to your galley drain is not part of the black tank system, so it never gets flushed. Make sure you keep it drained so it won't back up. I've also found if this tank starts smelling badly, a half cup of bleach sloshing around in some water clears it right up.
Dave

[Old-Biscuit]

The 'thingy' you found under the kitchen sink is call an 'Air Admittance Valve'

It is on the kitchen sink drain line to grey waste tank to allow air in when draining grey waste tank. It prevents the water in 'P' trap from getting sucked out. Water in 'P' trap is a water barrier so 'stink' from grey waste tank doesn't enter RV.
They are just hand tight....sometimes loose. Also the flapper/spring over time weakens and doesn't properly close. Cheap to replace. Hardware stores carry them. $3-$4

Should also be one on bathroom sink drain line.



The 'funky thing' you found in the bathroom is the 'black tank flush'
anti-siphon backflow preventer. It allows water to flow from water supply into black tank rinser but stops backflow of black tank water into water supply system
When water is turned off air is allowed to enter breaking any vacuum in system so no siphoning can occur. Can drip when turning water ON/OFF (Vacuum Breaker Model 571 by B&B)
Much more expensive.....$50+


YEP......GREY waste water STINKS!

How to prevent this from happening again.......dump tanks before they overflow.

I use the K.I.S.S. principle cause the tank monitor level indicators don't always work
When toilet 'burps'....time to dump black tank
When sink or shower stats to drain slower than normal.....time to dump grey tank(s)
For US..that is once a week. But I have 128 gallons of total waste capacity

[DavinD]

Hope you get it figured out.

[jmtandem]

By the time I got back into the galley to finish cleaning up the mess on the floor from the standing pipe spill over the stench was enough to almost knock both the bride and I out cold. The dog was at the exit door scratching for all he was worth to get out. I opened windows and turned on the fan in the bathroom and the stench eventually dissipated although even now there is a residual odor that is not very pleasant.

I don't know how to fix your problem but you are a good storyteller.