Does the soil stack in my attic need an AAV?

Discussion in 'Plumbers' Talk' started by Lansbury, Sep 13, 2017.

  1. Lansbury

    Lansbury New Member

    Rented flat at the top of a converted house. Only recently moved in, usual story - flush the loo and the bath trap syphons... bad smell in bathroom etc. etc.

    Went into the attic, took the AAV off the soil stack and flushed the loo - problem solved. Also noticed when turning the AAV upside down that it takes a few seconds and maybe even a bit of a jiggle before the seal moves at all.

    So seems reasonable the AAV is knackered?

    But what I can't establish is... what happens if I don't replace the AAV and just leave the stack venting into the attic space?

    Im feeling conflicted. The poor landlord will get ripped off by the management agency if I complain about the syphoning drain and they send out a plumber to investigate and fit a new valve... but I equally know the agency won't take my word for it and just pay for a new dergo for me to fit.... but I'm also loathe to buy a new one for a property I'll only be living in another 11 months when I don't feel it's my job as a new tenant to sort rubbish like this out.

    so what happens if I just leave the soil stack venting into the attic... just a bad smell in the attic or am I going to accidentally blow the roof of or cause some sort of natural disaster?
  2. KIAB

    KIAB Well-Known Member

    The purpose a of AAV is to seal off the vent pipe from any smells, & only operate when there is negative pressure,& then opens drawing in air to equalise the pressure.

    Last edited: Sep 13, 2017
  3. Lansbury

    Lansbury New Member

    Yep I get what it does.

    So if I take the AAV off... the worst that happens is the attic smells?
  4. KIAB

    KIAB Well-Known Member

    Yes, & you another thing with negative pressure, it can draw the water seal out of bath/basin traps allowing the smell into bathroom.

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