Forum Discussion

augustpilot's avatar
augustpilot
Explorer
Sep 25, 2013

Sewer odor, help please

First time. Tonight we have a strong odor of sewer. It is not coming from Toliet area but from under the lav cabinets Checked under cabinet, no leaks, the only thing I do not recognize are 2 pipes. The both come from under floor. They meet near bottom of counter. Where they are joined is a small white plastic container. It is round with a cap on top. They both go straight up from floor with this container at top. The odor is coming from under cabinet. Going to camping world in morning for new awnings so can have looked at. Thanks

Jim
Class A
  • garry1p's avatar
    garry1p
    Explorer
    Sep 25, 2013
    The thing with the cap on top is a one way vent and they do go bad and become a two way vent.

    Unless glued on the top pulls off and can be replaced easy fix.
  • Executive45's avatar
    Executive45
    Explorer III
    Sep 25, 2013
    Your grey tank needs flushing. Make sure all your "P" traps are full. Most likely cause is the ASTVD...:B...which is short for Anti-Siphon Trap Vent Device...Its purpose is to allow air into the drain system to help drain the sink while prohibiting gases and odors from coming in from the holding tank and drain piping. They are inexpensive and easy to replace. They are spring loaded with a rubber diaphram. Often this spring breaks or simply wears out. Available at any RV parts store. Also known as a vacuum breaker.....Dennis

    Here's a picture of one. There are others, of course.
  • Fishinghat's avatar
    Fishinghat
    Explorer II
    Sep 25, 2013
    garry1p wrote:
    The thing with the cap on top is a one way vent and they do go bad and become a two way vent.

    Unless glued on the top pulls off and can be replaced easy fix.


    X2

    These one way valves allow air to follow the waste water to the tank so the sink and shower will drain. When they fail, they become a two way valve (or no valve at all) and allow sewer gas into the coach. They are cheap and very easy to replace. ACE hardware has them in stock.
  • rockhillmanor's avatar
    rockhillmanor
    Explorer
    Sep 25, 2013
    More often than not if the smell is coming from the bathroom sink area the p-trap is empty. This water does evaporate if not used. It dumps into the black tank. Fill the sink up with water to fill p-trap.

    If you have not been using the RV, run water in your shower also. Gray water tanks DO smell also. Good Luck.
  • augustpilot's avatar
    augustpilot
    Explorer
    Sep 28, 2013
    Update, thanks everyone for the good information. I have two of these vents, kitchen sink and bathroom. As you advised , I went to,Lowes and bought the screw on vents.
  • zman-az's avatar
    zman-az
    Explorer
    Sep 28, 2013
    rockhillmanor wrote:
    More often than not if the smell is coming from the bathroom sink area the p-trap is empty. This water does evaporate if not used. It dumps into the black tank. Fill the sink up with water to fill p-trap.

    If you have not been using the RV, run water in your shower also. Gray water tanks DO smell also. Good Luck.


    He said under the sink so its most likely the anti siphon.
  • Bobbo's avatar
    Bobbo
    Explorer II
    Sep 28, 2013
    augustpilot wrote:
    Update, thanks everyone for the good information. I have two of these vents, kitchen sink and bathroom. As you advised , I went to,Lowes and bought the screw on vents.

    So, did it fix the problem?
  • rocmoc's avatar
    rocmoc
    Explorer
    Sep 29, 2013
    Thank you thank you thank you. Did not know about the vents. Went to Home Depot today and purchased two vents like these, http://www.lowes.com/pd_24372-143-85539K_0__ for $2.92 each plus tax. Replaced in minutes. When I looked at my old ones the rubber had swelled and did not lay flat sealing the gases in the gray tank. While we did not have a major odor problem, when we turned on the overhead vent fans gas was also sucked out of the gray tank. Thank you again to the OP for asking and the posters that responded.

    rocmoc n AZ/Mexico

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