Gray tank rotten eggs smell - galley tank - only 2/3 full?

[pilotchip]

We've had our new Rockwood Mini Lite 2506S for about a month or so. On the third trip one day the kitchen smelled really bad of rotten eggs. Assuming it was the galley tank (2nd gray tank) I emptied it and the odor went away.

We just got back and it did the same thing on 2/3 full indication.

There is no AAV under the sink. The plumbing goes out to the side cargo compartment and then one line goes to the tank I guess, and a second line goes through the sidewall and there's a little cap with a cover on the exterior. The cover is screwed on and there's silicone all around it.

Is this normal? Why would it stink so bad at 2/3 full? I was not leaving the line open to drain into the sewer. What if we wanted to dry camp? Thanks!

[Old-Biscuit]

Not real strange that galley tank vents via that exterior vent cap

WHAT is strange...w/o an AAV how is the SINK getting back inside the RV?
* Kitchen Sink 'P' trap loosing is water...no vapor barrier
* Are you SURE there is NOT an AAV on kitchen sink drain line
* Kitchen sink drain line has a crack
* Roof Vent ON in Exhaust Mode and pulling stink inside
* Batteries being overcharged/boiling causing that rotten egg stink

[SKP Kirk]

I am thinking that the picture above is the floorplan that you have with the kitchen sink in the front? It does seem strange for you not to have some type of vacuum breaker under the sink and those can sometimes stick open. It might help if you could post a picture of the plumbing under the sink. I am guessing that there is no roof vent for the tank either and that whatever that is on the side is intended to perform both the vent and the vacuum breaker functions. To me it sounds as though that is not working properly and the water is being drawn out of the P-trap under the sink. I would complain to the dealer you got it from, and if you use it before that, try adding a couple of cups of water to the trap after the sink is empty each time you use it.

It is actually quite normal for the gray tank odor to be as bad or worse than that from the black tank but it is normally vented out the roof so we don't experience it.

[Gary RVRoamer]

The amount of liquid in the tank has zero to do with smell. A little bit of the right (wrong?) kinds of food waste in a pint or two of water can generate a lot of stink. That's why sink & shower drains have P-traps and air-admittance devices have flapper valves. The P-trap should keep odors from exiting the sink drain into the interior, so need to investigate it to be sure it is retaining enough water to block gas feedback.


I too am guessing that outlet thru the sidewall is an air-admittance vent for the drain line. It should have a flapper in it - you wouldn't want an open gray tank vent right on the patio! It could be stuck either closed or open. Open would allow the stink outside and be noticeable there; closed could cause water to be sucked from the sink P-trap, thus allowing odors to the inside.

[Bob_C]

That is the vent for the galley tank.......no roof vent.....mine's the same way, but never gets smelly outside....

[SlowJoe]

Maybe it is missing the flapper that is supposed to be there. Manufacturing defect?

[shootist]

Originally Posted by Gary RVRoamer

The amount of liquid in the tank has zero to do with smell. A little bit of the right (wrong?) kinds of food waste in a pint or two of water can generate a lot of stink. That's why sink & shower drains have P-traps and air-admittance devices have flapper valves. The P-trap should keep odors from exiting the sink drain into the interior, so need to investigate it to be sure it is retaining enough water to block gas feedback.


I too am guessing that outlet thru the sidewall is an air-admittance vent for the drain line. It should have a flapper in it - you wouldn't want an open gray tank vent right on the patio! It could be stuck either closed or open. Open would allow the stink outside and be noticeable there; closed could cause water to be sucked from the sink P-trap, thus allowing odors to the inside.

This! Nothing smells worse than rotting vegetables and grease in a grey tank. I learned the hard way too. I now wipe all my dishes clean before washing them. I never put any kind of food waste in the sink. Not even a leftover cup of coffee.