Editor’s note: This information is provided courtesy of Escapees Club.
Q. I would like to know what would cause odor from the bathroom to come up into the RV during travel. When we stop, you can smell an odor when you step inside the fifth-wheel, but when stationary there is no odor. — Bill
A. Several possibilities come to mind. Do you travel with any vents or windows open on the trailer? One roof vent slightly open will create low pressure inside the RV and can cause sewer odors to be pulled into the coach.
Some of the older, less-expensive RV toilets don’t make a super great seal on the tank. Does the toilet bowl retain a small amount of water after flushing? If it doesn’t, then the blade seal or flushing valve mechanism is not sealing, and that can allow odors back into the coach.
It could also be an issue with where the black tank’s roof vent cap is located. The wind pattern over the top of the RV may create a high-pressure area at the roof vent, causing a slight positive pressure in the holding tank. Many odor problems of this kind can be remedied by installing one of those weathervane-style tank vent caps, like the Camco Cyclone or the Vac-U-Jet.
The Siphon 360 Fume Extractor is also a good solution to black tank odors. A Let’s RV blogger wrote a review of this product which you can read by clicking here.
These replacement roof vents create a low-pressure area at the roof vent opening and will help prevent tank odors from entering the RV while traveling. Most RV parts stores carry them.