Bathroom sink drain question

[Emmitt]

Hello,

First time poster here. Can anyone tell me if there is anything wrong with this bathroom drain? My concern is that the slight drop off, after the trap, is not correct.



(This is a close-up view of the slight drop off after the trap)


In the wall, the drain makes a 90 degree turn down.

Thank you.

 

[Jeff Handy]

It looks like it should work all right.

 

[Emmitt]

I am wondering if this slight drop off is causing a "S" trap scenario, and if it is possible that there is not a deep enough trap seal? Below are more detals about the issue we are facing with this sink ...

On some mornings, when we first use the sink, there is a "rotten egg" smell ... this smell is only there while the water is going down the drain, and it only occurs for about 5-10 seconds (again only while the water is going down the drain, and it is mainly in the morning ... the smell is not there all of the time).

Here are a few other things that we have learned already ...

• We know that the smell is coming from drain, and not from the water itself ... we know this because we tested by blocking the drain and filling up the sink ... then we released the drain ... and immediately when all of the water drained from the sink, the smell was there.
• We know that the sink is properly vented within 5 feet of the drain, and the vent goes up and out through the roof.
• This is the only drain in the house that is having this issue.
• We have "snaked" out the main house vent (which this sink vents into) and there is no obstruction in that vent.
• We use the shower and sink in this bathroom every night, and we use this sink several times throughout the day.
• This is the only drain in the house that is having this issue.
• There is a slight sunctioning noise while there water is draining, and if you run the water full blast for several seconds, the water does back up a small amount in the sink ... but once the water is turned off, the water drains fairly quickly.
• Lastly, the smell is not there every morning.

Thak you for reading all of the above ... and any suggestions to help diagnose are apprectiated.

 

[frodo]

Hello,



In the wall, the drain makes a 90 degree turn down.

Thank you.

the 90 turn down is an s trap



how to fix

 

[Rickyman]

The smell is most likely from muck buildup in the pop up assembly

 

[Emmitt]

Frodo - thank you for image with your notes. Do you think this S-trap could be the cause of the smells?

Rickyman - we have thoroughly cleaned the muck buildup in the popup assembly. Also, this smell started within the first week of installing this brand new sink with all new fixtures ... I wish the smell was coming from the popup assembly.

 

[frodo]

Frodo - thank you for image with your notes. Do you think this S-trap could be the cause of the smells?

Rickyman - we have thoroughly cleaned the muck buildup in the popup assembly. Also, this smell started within the first week of installing this brand new sink with all new fixtures ... I wish the smell was coming from the popup assembly.

s traps are notorious for causing suction that pulls the water out of the trap
which then lets the gas into the house.
this is the reason s traps are illegal

 

[Emmitt]

Frodo,

I just realized that I probably caused confusion with my earlier comment "the drain makes a 90 degree turn down". I neglected to also say that the pipe in the wall also makes a 90 degree turn up for the vent (see picture). So, I assume there is no need for the AAV right? But would you still say that the rest of your suggestions would be a good idea?



Thank you greatly for this dialougue.

 

[Diehard]