Originally Posted by B and B
But i have the same Problem with closed tanks., fan on, smell. I replaced the galley air valve last year, need to do the bathroom next.
Brian, these valves typically work great. I am willing to bet you have a different issue going on. I wish you had mentioned it at the rally, as I (or the tech team) could have looked at it.
Things to check:
Buildup between the toilet base and the flush valve plate (pressure wash or remove and clean - use new rubber seal to reinstall)
Bad seal between toilet and black tank fixture (reseal with new gasket)
Moldy damp hand towel under sink (found mine after an odor search)
No (or low) water in shower trap
No (or low) water in vanity sink trap
Slow water leak causing rot and mold
Cracked holding tank plumbing (not enough antifreeze in traps during winterization)
Running the fan creates a negative pressure in the camper that will pull air from whatever source there is. In a sealed plumbing system, the negative pressure should pull the flapper closed in the valve; not open it.
They are pretty simple devices and it stretches the imagination that you have (had) two bad ones in a year.