DonPd wrote:
If your problem is with the sink drains or vents check this out.
http://www.hepvo.com/
If your problem is odor from the tanks check this out.
https://360productsnorthamerica.com/site/
If you remove the outside cover for the fridge and see any yellow stains your fridge has a leak. The only fix is to replace the fridge or the cooling unit.
http://www.rvcoolingunit.net/servlet/StoreFront
well i replaced the 'cheater valve' and so far so good, I even did a tank flush and a had no odors however I ordered the hepvo.com valve for the gray tank for insurance. I assume my two gray and one black tank all have independent roof tank vents? I only ordered one as I smell the super foul odor from under the sink and seems like it only happens when I use the kitchen sink gray tank.