Installing Zoeller Laundry Sink Pump with basin (venting?)

[Charlie Mattina]

Hi all!

New to the forum but have a few plumbing questions for everyone. Any help would be appreciated.

The house I'm in has some odd(ish) plumbing going on, from a sewer tank system because we are below grade to a 250 lb concrete laundry sink we're (planning on) using. I bought a m53 Zoeller pump with a plastic basin to use for the laundry sink. Not a lot of lint or anything will be going through it, but just want a sink for dirty stuff in the basement.

The installation seems pretty straight forward, and i can tie into the drain pipe for the washing the washing machine, but tying the pump basin vent in the main vent is more difficult as the main vent is the opposite side of the house. I was wondering why the drain basin needs a vent at all? Could I stick a vent pipe on it and and let it vent into the basement? I do not see how any sewer gas will be coming back through it, as the discharge pipe is just going to be discharging into the same pipe that the washer dumps into, and no sewer gas is coming through that.

 

[Jadnashua]

That probably would work, but that tank can start to grow some nasties inside, and then it could start to smell. Without a vent, the pump basin wouldn't let waste water in after awhile...as there would be no way to expel the air that is displaced. That also means that an AAV won't work, since it only lets air in, and won't let it out. The best way is to tie the vent line to an atmospheric vent. Then, as the tank gets filled and emptied, air can move in/out to allow it to work properly.