23BHE Sewer Smell from Under Bathroom Sink

[FT4NOW]

Update. Replaced the air admittance valve recently. Out camping now and still getting the sewer smell from under our sink if I leave the grey valve open while hooked up. I don’t know what else it can be. Only solution for now is to leave my grey valve closed all the time except when dumping.

It's a good practice to leave the gray valve shut anyway, that ensures you have water available to flush the line/sewer hose after dumping your black tank.

The only other thing I can think of is if your shower doesnt use a traditional p-trap. On my Momentum the shower used a Hepvo trap which looks more like a rubber duck bill and if that is clogged even a little bit I could see it allowing gases back through the shower drain which could give you the smell you are experiencing.

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[Second Chance]

Update. Replaced the air admittance valve recently. Out camping now and still getting the sewer smell from under our sink if I leave the grey valve open while hooked up. I don’t know what else it can be. Only solution for now is to leave my grey valve closed all the time except when dumping.

We leave the gray tank dump valves closed all the time, anyway. This is so we have plenty of gray water to flush the stinky slinky and pipe tailings after dumping the black tank. Leaving the gray valves open can also result in sewer gas backflow from the park's septic or sewer system if that's not adequately vented (and sometimes sewer flies from the same source). We've experienced this in a couple of locations. As to the initial suggestions (AAV), both the kitchen and bathroom sink AAVs were so loose on our new Solitude that they were about to fall off and were causing the smell! Tightening them up fixed the problem.

Rob

[Dana H]

Update. Out camping now and still getting the sewer smell from under our sink if I leave the grey valve open while hooked up..

We had the a similar problem with ours except it was the gray tank for the kitchen which doesn't have an AAV but directly vents out the side wall, we too left our gray valves open but now we close them. I tried to attach a file of the plumbing schematic from GD for our Imagine 2450RL it will give you a perspective if nothing else.

The AVV in the bathroom system was very loose so I had to tighten it up, too.