Bathroom venting

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

Look under you kitchen sink and bathroom sink.......follow drain line.
Just after 'P' trap a sub pipe with a vent on it. Called an 'air admittance valve'. It opens when draining your galley/grey tank so that air can get into drain system and keep 'P' trap from getting sucked dry (water in 'P' trap provides odor barrier)



When they fail to close they allow tank odors inside rig.