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Pangaea_Ron's avatar
Pangaea_Ron
Explorer
Sep 29, 2014

Gray tank smells

I've posted about my problem before, and here is what I think is happening.

The gray water vent was installed low into the gray water tank, and did not project through the roof. I have corrected the issue as it projects through the roof plane and have installed a rotating venturi vent, which helps.

I have tried pulling the thru roof vent line upwards (as others have suggested), but it is restrained by a lateral shower drain, and cannot be raised.

When the tank fills (about 2/3 full), the bottom of the vent is submerged below the water level in the tank, and gases find another way to escape, and that is usually through the kitchen sink drains. If I close the drains, and fill the sinks with a bit of water, the smells do not occur. The "P" trap below the sinks does not seem adequate to prevent the smells. I have replaced the under-counter vent frequently.

I am considering putting a "T" in the vertical line to the under-counter vent and running a vent line downwards through the floor level to the exterior below the chassis. It's not a perfect solution. but running a vent line to the exterior is not possible through the roof or wall. It seems like the gasses should follow that route rather than upwards through the sink drains.

Dropping the tank to investigate seems like a formidable task.

Any thoughts?
  • I have seen a new option, can't remember where, but it replaces the P Trap with a self closing kind of sleeve....it can be mounted Horizontally or Vertically, and had great reviews, I think It would solve your problem....search around, if you can't find it post back and I will hunt around....
  • Your issue is 'physical' in that the vent line gets blocked by level in tank.....chemicals/foo-foo odorants won't resolve your problem

    When vent gets blocked off pressure builds every time you put more water in (sink/shower etc.) as water is heavier than air so the air has to get pushed out.

    The air admittance valves are designed to CLOSE under pressure (unless worn out and don't seal) so the air gets pushed up thru 'P' trap.

    Tying into the vent line portion (not drain line section) will allow air to escape tank as water drains into it....even if it goes downward and out thru floor.
    Not the most ideal corrective or conventional measure.....but easier than dropping tank, pulling vent line and cutting it off then reinstalling vent line/tank PITA!!!

    Is there enough room on vertical section of stub pipe where air admittance valve is installed to cut and put a 't' in???

    Mine stub pipe is very short
  • Ours was pretty stinky, so we tried some of this stuff:

    TST Gray Water Treatment

    No more stink. Before you go to a whole lot of labor, you might try using some of this odor controller first.
  • Can you run a vent line from the area of the Ptrap to the vent tube, son that the gas travels up to the T fiting before the P trap and onto the vent tune?

    navegator

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