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Sewer Ejector Pump

nycpa Member Posts: 108
Hi guys,

I wanted to know how to vent a Liberty 370 sewer pump.  Its located in the basement slightly below the sewer line.  Can I vent it with a Air Admittance Valve or can I vent it by attaching it to my main vent?  The one that came with the house has this little black thing on top called a trap vent but once in a while it smells pretty bad around that area, like rotten eggs.  If I can use a Air Admittance Valve, what DFU do I need?  I see 20 and 160 on online stores.  Or if I attach it to the main vent, will it cause a disruption to the other plumbing in the house?

Thanks for the responses. 


  • Alan (California Radiant) Forbes

    In my area which uses the Uniform Plumbing Code, we always ran a vent through the roof or tied it into another vent, properly sized of course.  But it's been awhile since the last time I installed one and codes have changed.  Check with a local plumber or supply house; the best would be to call your local inspector.

    I don't think you want to use an air admittance valve.  I've used them on small ejectors and they create a pressure build-up that causes the system to malfunction.
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    Two btu per sq ft for degree difference for a slab
    STEVE PAUL_3 Member Posts: 126
    sewage ejector venting


    Most sewage ejector manufacturers disapprove of using automatic air admittance valves for venting the sewage ejectors and laundry tray pumps. The reason is that they will in fact open when the pump is running to relieve the vacuum in the vessel, but they will also close and create an air lock when the vessel is filling. This air lock will cause slow fixture drainage and gurgling. Best to run an independent vent through the roof or connect to the building vent system. As an aside, why do they call the "vent" a "vent"? It actually is a "vacuum relief". 
  • nycpa
    nycpa Member Posts: 108

    Thanks for the replies guys. I know what to do with the vent.
  • clarasmithh001
    clarasmithh001 Member Posts: 1
    Sewer Ejector Pump

    Sewage ejectors are generally found in households and office buildings with basement or underground toilets.Sewage leaving basement toilets is collected in a tank containing a pump and float.

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