I went camping in my 24 foot 2017 Thor Synergy RV Class C with Mercedes sprinter chassis for a few days and during the travel back to our home wife and I both smelled a bad odor while driving. Upon arriving at home, I went into the bathroom and smelled the toilet, the shower and the bath sink. No bad odor. I smelled at the kitchen sink- no bad odor.
I drove from home to storage facility and smelled more bad odor while driving. I dumped the Black and Gray Water tanks and ran fresh water thru black tank. I took it for a drive - no bad odor.
We don't think it is a propane leak. Suggestions or ideas about what may be causing bad odor
Look in the bathroom cabinet; you should find a pipe with a cap on it. The cap is an air admittance valve (it is a one way valve: lets air into the black plumbing but not out). Check that it is on tight and not loose.
Thanks for comments. Not sure how I would be creating negative pressure. Will follow up with RV repair here in St George and will look into fancy air vent caps and will check bathroom cabinet for loose cap.
If the ceiling vent in the bathroom is open when you're driving: it can pull air up and out of the bathroom... This creates a slight negative pressure in there, and that can draw the fumes up out of the tank.
If the air admittance valve is loose: it's just a natural way for the "ugliness in the tank"; to find it's escape route...
The fancy vent caps are cute... but certainly not a necessity.
(They just appealed to my sense of humor! )
"What: me worry?"
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW