Black Tank Venting

**Second Chance** · 04-30-2022, 08:33 AM

Originally Posted by Grandesigner

Looks like the bathroom gray tank and black tank share a vent and have an AAV under the sink. The galley sink does not have one, I guess since it has its own vent.
I'm jealous and confused as to why and how not using black tank solution does not result in normal human biological 'smells' for some...what is the secret?

I would be extremely surprised if there is not an AAV on the galley sink... it may be tucked up somewhere not easy to see or access.

Rob

**Grandesigner** · 04-30-2022, 08:41 AM

I will have to pull out both under sink drawers to take a closer look...maybe today. Anyway, the source right now is not AAVs from what I can tell.

Edit; pulled both drawers and stuck my head in there...found it.

**DragonDriver** · 05-04-2022, 03:05 PM

Are you remembering to turn off the fan BEFORE you flush? I even close the roof vent since a fair breeze will "siphon' air up out of the black tank when the "ball is dropped. "

**Grandesigner** · 05-05-2022, 08:30 AM

I guess anything is possible after 30 years of doing this, lol
The thing is, before the eco friendly black tank solution, I don't recall having this problem...

**DragonDriver** · 05-05-2022, 08:39 AM

Originally Posted by Grandesigner

I guess anything is possible after 30 years of doing this, lol
The thing is, before the eco friendly black tank solution, I don't recall having this problem...

So mebbe the "new to you" blank tank solution is leaving some "debris" behind? I know that some folks have reported that when they used the Geo-method they started experiencing foul odors, especially during and after the dumping process. At least one person switched to "Happy Campers" brand and now they swear by it.

I'm very interested in how you (HOPEFULLY) finally resolve this.

**JimHie** · 05-08-2022, 07:55 PM

Had same issues even burping…tried various things. Even called GD. …
Finally decided I had TP stuck in vent tube.
Filled all tanks to absolute max
Pulled all valves at same time…hopefully to suck paper out.
Must have worked…no more stink

**Grandesigner** · 05-09-2022, 08:04 AM

^ that's what I thought also and did the same after using black tank blaster. I won't know until go out again, finger's crossed.

**rottekatz** · 08-27-2023, 08:12 AM

Use Banana oil. That is what the Army uses show effectiveness of protective (think gas) masks. It won't harm the system.

**BillandLisa** · 09-19-2023, 08:33 PM

I have a new 2023 367 BHS and we have a similar issue but only when the tank fills up to the 2/3 level. At that point we go from no smell to strong spell in a single flush. I "believe" the issue is that the vent pipe that is connected to the tank that connects with the other tanks and goes to the roof vent extends too far into the black tank and once the liquid level in the tank gets high enough the opening of the pipe is submerged and the gas vents into the rig when the flush valve is cycled. Once I drain the tank below the 2/3 level smell goes away. Any other ideas on what could be causing this intermittent issue?