Forum Discussion

Dogpa's avatar
Dogpa
Explorer
Jul 17, 2013

Sewer Smell

I have a 2005 Mandalay 40B and have owned since 20,000 miles, has 34,000 now. It has always had a bit of a sewer smell when driving. I do not run with vents open, both tanks have been bleached but on recent trip I received smell through dash A/C, crazy right? I had in shop and they replaced the pop vent valves,(3), saying they were bad and that was the problem. Drove away 20 miles to next destination and same thing. Any suggestions? I did call the repair facility and they advised to clean tanks, which I had already done.
Class A
  • 1492's avatar
    1492
    Moderator
    Jul 17, 2013
    Welcome to the Forums! :)



    Moved from Forum Technical Support
  • Dogpa's avatar
    Dogpa
    Explorer
    Jul 17, 2013
    Thanks for the quick response ans I will research.
  • SkiingSixPack's avatar
    SkiingSixPack
    Explorer
    Jul 17, 2013
    On our much older motor home, what I thought was sewer smell turned out to be my coach batteries boiling away creating a sulfuric smell that I and others blamed on the sewer. My converter was bad and overcharging the batteries.

    Maybe it is a bad alternator over charging your chassis battery??? Just a thought and something that is probably pretty easy for you or a tech to check out.
  • Jim's avatar
    Jim
    Explorer
    Jul 17, 2013
    You can get plastic plumbing 'T's for $3 each, in the bathroom repair section of Home Depot. Works just as well as the commercial device made for RVs at 1/10th the cost.
  • barnaclebill's avatar
    barnaclebill
    Explorer
    Jul 17, 2013
    SkiingSixPack wrote:
    On our much older motor home, what I thought was sewer smell turned out to be my coach batteries boiling away creating a sulfuric smell that I and others blamed on the sewer. My converter was bad and overcharging the batteries.

    Maybe it is a bad alternator over charging your chassis battery??? Just a thought and something that is probably pretty easy for you or a tech to check out.


    Good idea!
  • Wheel_Estate's avatar
    Wheel_Estate
    Explorer
    Jul 17, 2013
    there are 'vacuum breaks " like what goes in near washer or dish washers in the home, on some MH .... time allows them to dry out and seep odor from the GRAY tank
  • mlts22's avatar
    mlts22
    Explorer
    Jul 17, 2013
    I'd check the AAVs (air admittance valves) which likely are near sinks. These allow air in, but not out, and sometimes the diaphragm fails. Fairly easy repair, just unscrew the old one, screw in the new one, call it done.
  • Executive45's avatar
    Executive45
    Explorer III
    Jul 17, 2013
    Finally, check the "P" trap in the washer....if you haven't used the washer in awhile, the water evaporates and will allow a sewer smell back into the coach....Dennis

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