Laundry Room Sewer Smell After Sink Addition

[sskicker23]

Hi All,

I recently remodeled my kitchen and laundry room in a 1970's ranch. I hired a highly reviewed master plumber (who completed the work) to rough in the supply and drain line for a new undermount sink. The laundry room is on the front left corner of the house near the entry walkway. The sink is on the front wall and the washer and dryer are on the left wall on the back side of the room. The plumber opted to use an AAV in the sink base cabinet and tie in the waste line into the washing machine drain after the p-trap. The washer tied into a 3" vent pipe (that goes thru the roof) after the p-trap and now after the laundry room sink drain.

The picture makes it looks like the pipes arent sloped correclty but they all have a downward slope of quarter bubble or more

After a couple of months the laundry room now smells like sewage. The room did not smell at all for the first year before the remodel.Both the sink and the washing machine drain without issues or gurgling sounds. I have snaked all of the drain pipes and the vent pipe. Water flows freely down all of the pipes. The smell comes from the washing machine and not the newly added sink.

My original thought was that when we used the laundry room sink, it created a siphon and sucked out the water ptrap. However we tested not using the sink and yet it still smells.

Does the current plumbing setup look ok? Did the plumber tie into the correct spot or should it be further down?

 

[WorthFlorida]

Cold be mold growth in the washing machine. Google "washing machine moldy smell" that is if you have a HE machine particularity a front loader.

To be sure plug the sink drain and fill it with a little water to seal it as a possible source of the odor. You can remove the washing machine drain hose and stuff a wet rag in the pipe to also seal it off and then wait. You might be able the screw off the AAV and check that it is closed and not stuck open. If you cannot remove the AAV cover it with a plastic bag and tape it shut. These are for items that cold be the source.

 

[Sponsor]

 

[Reach4]

I am not a plumber. Washer p-trap should not be under the floor in the US. New sink drain should join the waste going the correct direction. It looks like that drain pipe is pointing upstream at its exit, but should point downstream. If "Vent" were the vent for the p-trap, the sink would need to tie in downstream of that vent.

The washer tied into a 3" vent pipe (that goes thru the roof) after the p-trap and now after the laundry room sink drain.

It is not clear what you are saying there.

So I think your question is whether the pictured hookup could explain the smell. I am not sure. Your washer trap riser is very long. However washers typically end up with dribbling at a low rate, so could refill the trap that got siphoned out due to the too-long riser. So I don't know.

 

[Terry]

It looks like you don't have venting for your washer, and I can't see how the added sink was done.
The p-trap for a washer is on the same floor and vented like this.
In this picture, there is a vent from the floor below that ties in above the height of a washer.