Bathroom venting

slarsen wrote:
See, Thomas, the odor went completely away when I 'plugged' the under-counter vent. And given that there are three tanks, what would be the purpose of connecting the sink to the black tank? The sink is right adjacent to the shower, closer even than the toilet. It may be that some sinks are connected to the black tank, but I see no evidence of it in my Mountaineer. I just wondered if the plumbing might share the venting.

Several hundred more miles today, still absolutely no odor issues. No question in my mind after more than a week of travel: the vent was the issue. I'm going to find a better quality replacement; I see they are available for about $20, even from Amazon.

Old-Biscuit wrote:
Some bathroom sink drains are connected to black waste tanks....

slarsen wrote:
GMC4ME, I can virtually guarantee you have at least one, in the bathroom alongside the sink. It has to be as high up as it can be, to work properly. There was just room enough for me to unscrew mine to inspect and 'plug' it temporarily.

I too have three holding tanks because of the rear kitchen. I've never noted any odors from the kitchen sink, but maybe someday . . . I can imagine the kitchen sink smelling, because of the small scraps of food that end up going down the drain.

I'm still shocked at the notion that the grey water that serves only the bathroom (shower, sink) could smell so bad, but I guess it is what it is.

Thanks, Old Biscuit, for providing the picture. That's exactly what mine looks like.

GMC4ME wrote:

slarsen wrote:
Having read and contributed to a couple recent threads about horrible odors in the bathroom, and noting that I closed off the vent alongside the sink which completely eliminated the odor for me (yes, I'll replace the vent when I have the chance, I'm in tiny town CO now) I am wondering:

Is it possible that the vent is actually connected to the black tank, even as it is intended primarily to prevent sucking the water out of the P trap under the sink?

I ask, because the stench was horrible. Raw sewage smell. I just find it hard to believe that the silky white water that comes out of the grey tank could smell like that. All it is, is shower water and hand-washing water. I haven't gone on the roof to count vent stacks, but I just wonder if the manufacturers might be connecting the venting together somehow. It isn't as if the vent by the sink could result in actual water/waste coming in, and if the vent was working properly, there shouldn't be any fumes or problems . . .

Just wondering.

I have three holding tanks on my Arctic Fox fifth-wheel. I am not aware of any "vent alongside the sink". Can you explain what/how you did? I might have one and don't know it. Always willing to learn!

Thanks - Wes

slarsen wrote:
Having read and contributed to a couple recent threads about horrible odors in the bathroom, and noting that I closed off the vent alongside the sink which completely eliminated the odor for me (yes, I'll replace the vent when I have the chance, I'm in tiny town CO now) I am wondering:

Is it possible that the vent is actually connected to the black tank, even as it is intended primarily to prevent sucking the water out of the P trap under the sink?

I ask, because the stench was horrible. Raw sewage smell. I just find it hard to believe that the silky white water that comes out of the grey tank could smell like that. All it is, is shower water and hand-washing water. I haven't gone on the roof to count vent stacks, but I just wonder if the manufacturers might be connecting the venting together somehow. It isn't as if the vent by the sink could result in actual water/waste coming in, and if the vent was working properly, there shouldn't be any fumes or problems . . .

Just wondering.