Smell from kitchen island sink with "out" studor valve

[Richard Spackmann]

All - hoping you all can shed some light on my dilemma.

I have some smell coming from my kitchen island sink when I am only running water - and I'm pretty much convinced its coming from the sink and not the studor valve (under the sink smells fine).

I attached some primitive pictures to try and illustrate how things are configured (I can try and get picture from under the cabinet itself if that will help).

So the question is - why does the sink smell? did I not install the studor properly? Is the wye or the few 90s interfering with the operation of the AAV? Is there too much of a vertical drop that the trap is being siphoned?

A couple of additional details:

1. studor vent is pretty high in cabinet just above the bottom of the sink
2. its not entirely plumb - it is "close" but I am starting to question how sensitive they are to being level?
3. the drain coming out of the cabinet back has a slight upward pitch to it (it's nearly level)

Hoping its some sort of obvious issue without having to redo the drain.

Many thanks for all your help with this!

 

[WorthFlorida]

Real pictures would be better, if not;

Is it only happening at this sink?
When hot water or cold water only is used or doesn't matter.
Is this a single or double bowl sink?
Is there a garbage disposal?
Have you opened the p-trap and cleaned it?
Is the drain pipe PVC or galvanized steel?
When did the odor start?
Is there a dishwasher drain connection?

If there is a garbage disposal, the grinding chamber it's more likely the source. Remove the rubber diaphragm and the odor may increase while not running the water.
You can pour down a cup or two of bleach and let it sit a while? If there is a garbage disposal, run it a second or two to spread the bleach.

 

[Sponsor]

 

[Richard Spackmann]

WorthFlorida - thanks for the reply - answers in red.

Is it only happening at this sink? The smell is only at this sink and doesn't matter hot or cold water.
When hot water or cold water only is used or doesn't matter. doesn't matter
Is this a single or double bowl sink? It's only a single small stainless steel sink
Is there a garbage disposal? no garbage disposal
Have you opened the p-trap and cleaned it? not yet...but did put drain-o in this week (see below)
Is the drain pipe PVC or galvanized steel? PVC
When did the odor start? intermittent for a few months now - but seems fairly regular now (maybe we are just sensitive to it)
Is there a dishwasher drain connection? no dishwasher

This week I put some drain-o in the sink to try and clean anything out, so I'm not thinking I need to put any bleach?

I totally forgot to mention another key piece of information (I updated the original post), the drain coming out of cabinet wall is slightly upward (almost level), but the sink drains well - but this may be a symptom?

I'll try and get a pic...

 

[WorthFlorida]

Obviously water doesn't flow uphill and it will allow more water and crud to lay in the pipe and trap. When you remove the p-trap it should be full of water. Do you hear any gurgling whereby the trap is being siphoned dry? It could be the pitch is allowing the water to flow too slow and the AAV is not opening thus water is being siphoned out of the trap? Just guess for now.

I also have an island sink with a AAV, disposal and dishwasher. Never had an issue.

 

[Richard Spackmann]

WorthFlorida - of course, as I said, its slight and a short run, and the water never drains poorly. I'll pull the p-trap and take a look and see if I can get a picture.

 

[OLD TIMER]

The AAV,s go bad. I changed one the other day.

 

[Reach4]

What is the smell? Chemical? Decomposition?

If you close the stopper on the sink, and add some water, is the smell blocked?

 

[Richard Spackmann]

@Reach4 - it smells like septic - yes, the smell does not exist after filling up the sink with water. I'm about to pull the trap and have a look - I'll post back with progress

 

[hj]

The way you show the piping, you have pretty much negated ANY BENEFITS from the Studor vent and have installed a "perfect" "S" trap which will usually ALWAYS siphon and smell.

 

[Richard Spackmann]

@hj that's interesting...I'm not following how it creates an "S" trap however...can you elaborate?

The only difference (and I'm not saying its an insignificant one) between my setup and this picture https://terrylove.com/forums/index.php?threads/sewer-gas-smell-at-kitchen-island.78381/ is that I have the studor vent on the vertical rather than the horizontal....

I'll post back an actual picture shortly...

 

[Cacher_Chick]

Post a couple photos of the drain and vent piping and then we might be able to tell you how to fix it.

 

[Richard Spackmann]

pictures of the piping under the sink - you'll see the right elbow coming out from the sink back going vertical and the AAV installed on top of that pipe to the right of the sink drain

 

[Reach4]

Your AAV is not hooked up properly. HJ figured it out. Too, me a while.

Your AAV needs to hook up at the level of the trap arm or above.

If you post a photo of the backside, somebody may offer a way to fix this more easily.

 

[Richard Spackmann]

@Reach4 - I think I see what you are saying, I installed it with the wye lower than the p-trap to prevent siphoning the drain - are you saying that's the very behavior I ended up creating?

 

[Reach4]

@Reach4 - I think I see what you are saying, I installed it with the wye lower than the p-trap to prevent siphoning the drain - are you saying that's the very behavior I ended up creating?

Yes. You want the vent to be able to supply air to the trap arm to spoil the vacuum.

 

[Richard Spackmann]

@Reach4 thanks - so I'm assuming if I just follow the install here: https://terrylove.com/forums/index.php?threads/sewer-gas-smell-at-kitchen-island.78381/ I'll be fine? My plan is to turn the current locaton of the AAV into a cleanout (I'll remove the bend and put a cleanout in its place)

 

[Reach4]

Yes. That would be one of the right ways.

 

[Terry]

The way you show the piping, you have pretty much negated ANY BENEFITS from the Studor vent and have installed a "perfect" "S" trap which will usually ALWAYS siphon and smell.

Thanks HJ, I've been busy this week, and this is the perfect response. He should add an AAV on the trap arm between the p-trap and the wall. The existing AAV is doing nothing.

 

[Richard Spackmann]

I modified the plumbing in the manner illustrated by @Terry and so far everything smells great - and I think it drains faster too! (which would make sense). Thanks everyone for the help!

 

[hj]

quote; I think it drains faster too!

Actually, it might have drained faster the old way. Improper venting CAN cause drains to drain faster since gravity is helping if there is nothing to break the siphon.