On a 5 week long western swing from Tullahoma, TN.. We have a 2017 Flagstaff 832 IKBS. Three days into our trip noticed a bad smell coming from under the kitchen sink. Called Flagstaff Tech Center and was told it maybe that the "stink" pipe for gray tank had come lose and slid down into the tank allowing the odor to come back into the kitchen area. The tank then would have to be removed and repairs made. But I called the dealer and the service manager suggested removing the "flapper cap" under the sink ad cleaning it. The cap screws off - so I did. Replaced the cap and bingo no more oder - until two days when the tank was about 2/3s full and there it was again. Been unable to locate a new flapper so put duct tape over the opening after removing the flapper cap. It maybe that a new cap will fix the issue. Along just for general info there's another cap just like it in the bathroom. So why didn't I switch the two since they most likely on the same drain line - not sure.. Just wonderful anyone else has run into the same issue.
that is the air vent for the plumbing not the tank. If you tape it up yes the smell may go away but the fixtures being serviced by that air vent won't drain properly. Replace the camp with a good on. Give some thought to installing a cyclone vent on the gray stack on the roof to help eliminate the smell and also read up on the geo method good luck
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Retired Navy
Jake my sidekick (yellow Lab) 10/04 - 05/20
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho
As Seadog mentioned , the cap that you replaced should be an air admittance valve. You might have one under your bathroom sink as well. I would replace them all. They do go bad and allow the gases back in.
I've been lucky and have never had this issue (uh oh, I probably just jinxed myself )!
But I have read from others that have and a temporary fix until you can get a new part is to put a plastic baggie over that vent under the sink with a rubber band or zip tie to seal it up.
Thanks, planning on heading to Home Depot as soon as we make it back home and pick up two new vent caps. I do the geo about every 3rd dump for both gray/black tanks. Thanks again..