Basement Utility Sink Waste Pump - How to vent to gag the gurgle

[Garrett Spitzer]

When I finished the upstairs laundry room for my wife, I got the old laundry area in the basement so that I could wash all of my dirty clothes and jackets that she says I should just throw out - those holes in my Carhartts are great conversation starters. To make it more of a man space I added a utility sink, but it needed a waste pump. I started with one of those direct under the sink mount pumps and it worked for about a year. The washer setup never had a vent, not even a cheater, adding the pump was helping to vent and clean out the lines. I figured I would try a floor sump model instead of replacing the under sink unit but I am having some trouble with how to vent it well. I do know that a vent to the roof is the best solution. I am using an AAV because the roof is 3 stories away and all spaces above this room where I could cut into a vent are finished; plus this is not going to be a laundry area forever and the AAV is completely accessible. I have always vented to the roof but I figure that this is the one case where I can justify the AAV.

So I cut in the vent for the waste pump as outlined by the manufacturer but as you can see I have the washer drain right in the middle of the setup which gurgles when the pump shuts off. Not really a surprise in hindsight but a bit of wishful thinking on my part. So my question is which option would work best:

1) Move the washer drain to position #1
2) Tie into the horizontal vent line and cut into the drain line with it at position #2 or #3
3) Or is there another option that I am not seeing

Thanks for the great resource. I get a lot of great info from the old threads. And you guys really helped when I needed it on my kitchen island vent loop (see no AAV there!)

 

[Bannerman]

The discharge flowing through the laundry standpipe 'Y' connection, will be causing a vacuum on the side branch which will suck water out from the standpipe trap.

The vent line from the AAV would have been better connected to the laundry standpipe trap arm instead of position #1, but installing an additional AAV in the trap arm between the standpipe trap and the Y fitting will allow air to enter which will prevent water within the trap from being sucked out.