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dutchev's avatar
dutchev
Explorer
Nov 23, 2014

**** foul odor ****

We have been fultiming for 4 yrs. and have a 2007 fifth wheel. We don't have a sani-flo system so i use a Flush King gate valve to back wash my black water tank. After every dumping i refill the back tank with fresh water at least 2 times. I have a clear elbow so that i can see it flowing. My question is that lately i have been getting a foul odor from the toilet when we flush. I also use the odor liquid every time. Whats up with this?
  • wolfe10's avatar
    wolfe10
    Explorer
    Nov 23, 2014
    I would suggest your approach is incorrect. You will never succeed in making a gray or black tank contents "smell good" or "not smell".

    Instead, concentrate in keeping the odor in the tank from getting into the interior. This is done by keeping air pressure in the tank lower than that inside the RV. There are several venturi-based devices that mount on the roof vent for the tank that help.

    Also, check the air admittance valve under the sinks. Their rubber can dry out and allow gray tank odor into the interior.

    Of course, there could be a physical reason for the change. For example, the vent pipe may have slipped down into the tank, a bird or insect nest may be blocking the roof vent, etc.

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