Help with Basement Stinky Sink

[sburns]

Hi all

First time posting here, this site always comes up in searches and has been a great resource. Usually I've found the answer without having to create my own thread, but this time I need some more direct help.

I've been dealing with a issue in my 2 piece basement bathroom. The sink when first turning on the water will stink up bad from the drain, after a bit, sometimes the water will start to fill the sink as it backs up, then slowly drain. I've tried to add an AAV valve under the sink. It sometimes helps but not always. I may have not put it together properly. I was thinking of trying again, but before I did I thought I would get your input.

Here is the current configuration under the sink

Here is what I'm thinking to try next (excuse the crude drawing)

Let me know if this will work, or if you have better suggestions, or questions?

Thanks!

 

[GReynolds929]

Have the drain cleared there's most likely a blockage somewhere downstream.

 

[Sponsor]

 

[Reach4]

1. Can you lift the stopper out? If you lift out the stopper, does the sink drain slowly or does it drain better?

2. Did this work fine for a few months or more, or has it been like that pretty much from the beginning?

3. Did you put this sink in?

4. If you close the stopper, will water go down the overflow if you raise the water level?

 

[sburns]

1. Can you lift the stopper out? If you lift out the stopper, does the sink drain slowly or does it drain better?

2. Did this work fine for a few months or more, or has it been like that pretty much from the beginning?

3. Did you put this sink in?

4. If you close the stopper, will water go down the overflow if you raise the water level?

Thanks for the reply.

It's always been like this. I had another config under the sink, but changed it to what is in the photo.

The drain is a pop up stopper. I can't remove it.
But when the water does fill up in the sink I can "pump" the stopper and it helps flush out the water in the sink and drain better, even while the water is running.

I put the sink in, and drain under the sink.

I haven't tried that, actually I just looked there is no over flow on this sink. My other bathroom sink has one.

 

[sburns]

Have the drain cleared there's most likely a blockage somewhere downstream.

There could be some underlying issue below. I will look into this.
Do you think the AAV setup under the sink is ok?

 

[Reach4]

AAV setup looks fine, and even if it did not, that would not cause slow draining.

What I am wondering is if your drain pipe does not connect to the overflow on the sink. The overflow on the sink should also vent the area below the stopper, and that prevents air pressure from building there. If you had the wrong drain hardware, and the water that went down the overflow but did not drain water or pass air, could give stagnant water that could develop a smell.

I am not concluding that is your problem.

If you run a soda straw down around the open stopper, does water drain better?

 

[sburns]

AAV setup looks fine, and even if it did not, that would not cause slow draining.

What I am wondering is if your drain pipe does not connect to the overflow on the sink. The overflow on the sink should also vent the area below the stopper, and that prevents air pressure from building there. If you had the wrong drain hardware, and the water that went down the overflow but did not drain water or pass air, could give stagnant water that could develop a smell.

I am not concluding that is your problem.

If you run a soda straw down around the open stopper, does water drain better?

Interesting, lemmie give it a try, Iet me get back to you.

 

[sburns]

Hey all, been meaning to follow up with this.

I had a problem with my basement shower it was backed up for a while. Different chemicals didn't work, neither did the 2 drain snakes I have. I had to rent a powered drain snake and finally got the clog removed.

With that fixed everything seems to be in better working order, as the shower drain is connected to the main stack which everything else goes into. The so maybe that clog was impacting the sink. IT seems to be flowing/draining better. But it still stinks from time to time, and I'm worried what else, vapour wise coming out of there.

Now I'm not sure what else I should do with the stinky sink.

 

[Reach4]

Hey all, been meaning to follow up with this.

I had a problem with my basement shower it was backed up for a while. Different chemicals didn't work, neither did the 2 drain snakes I have. I had to rent a powered drain snake and finally got the clog removed.

With that fixed everything seems to be in better working order, as the shower drain is connected to the main stack which everything else goes into. The so maybe that clog was impacting the sink. IT seems to be flowing/draining better. But it still stinks from time to time, and I'm worried what else, vapour wise coming out of there.

Now I'm not sure what else I should do with the stinky sink.

Maybe the snaking did clear where the sink and basement shower drain lines joined. If there was primarily a clog downstream of the joining, the shower would have overflowed before the sink backed up.

1. Sniff under the sink to make sure there is not a smell there. Replacing a leaky AAV should be pretty easy.

2. When is the sink stinking? -- when you have not used it for a while, when you shower, when you start using the sink, after you drain a sink full of water quickly?

 

[sburns]

Maybe the snaking did clear where the sink and basement shower drain lines joined. If there was primarily a clog downstream of the joining, the shower would have overflowed before the sink backed up.

1. Sniff under the sink to make sure there is not a smell there. Replacing a leaky AAV should be pretty easy.

2. When is the sink stinking? -- when you have not used it for a while, when you shower, when you start using the sink, after you drain a sink full of water quickly?

Thanks for the quick reply

I'll have to check that.

It stinks in the morning usually at first use. After a bit of water it seems ok. Then off and on. IT does stink up after using the shower as well.
Sometimes I keep the push drain down and leave some water in the sink so the stink doesn't keep making this fowl smell.

 

[sburns]

@Reach4 I want to show you something and get your input. I was going to make a new thread about my stack.

Here is the stack behind the wall. I had to correct this as the original setup the fixture between the ABS to the rest of the stack wasn't connected properly. The rest of the stack upwards is galvanized steel pipe.
When I redid this I've added more airflow and isolated each drain pipe into the stack.
It works well everything basically drains well, but something about it bothers me. Part of it I think is related to the sink drain and how it stinks. The only way I can explain it is, almost like there is too much air coming back from the main drain in the floor and flowing back into drain pipes and possible back into the house. Only the sink stinks up like poop/sewage, but what I am worried about is other vapours in a drain system like ammonia or methane gases I can't smell.
Does that make sense?

Take a look

 

[Reach4]

I am thinking that putting in a trap adapter, and using a slip-joint reversible trap could help. It would give you a port for snaking with a small snake, but it would also let you turn the trap around to give you a 2-inch "water seal" (AKA trap seal) instead of a 1 inch water seal. https://forms.iapmo.org/email_marketing/codespotlight/2017/July20.htm has a picture of how to measure the trap seal.

What I am concerned about is if there is room for the trap adapter, but it looks to me as if there is.

For diagnosis, once you have the trap adapter, you could try a clear p-trap. That way you could see any pressure differences.

Google Search

Those may not be as robust as the standard plastic (typically white or black polypropylene) p-trap, but probably more than durable enough.

 

[Reach4]

Here is the stack behind the wall. I had to correct this as the original setup the fixture between the ABS to the rest of the stack wasn't connected properly. The rest of the stack upwards is galvanized steel pipe.
When I redid this I've added more airflow and isolated each drain pipe into the stack.
It works well everything basically drains well, but something about it bothers me. Part of it I think is related to the sink drain and how it stinks. The only way I can explain it is, almost like there is too much air coming back from the main drain in the floor and flowing back into drain pipes and possible back into the house. Only the sink stinks up like poop/sewage, but what I am worried about is other vapours in a drain system like ammonia or methane gases I can't smell.
Does that make sense?

Air coming up thru the floor drain is odd, and could be related to the floor drain trap drying out.

That clear p-trap could be useful for diagnosis.

Your picture has some weird things going on IMO. That tee to the upper left... is the left port blocked? Is that just intended to add extra venting, or is there drainage coming into that from left to right?

The tee in the upper right is also odd. Just trying for extra venting?

There is a way to measure the pressures/vacuum in your pipes, other than using the clear p-trap. https://terrylove.com/forums/index....+manometer+tubing&c[users]=Reach4&o=relevance has various posts where I have posted about that.

 

[sburns]

Air coming up thru the floor drain is odd, and could be related to the floor drain trap drying out.

That clear p-trap could be useful for diagnosis.

Your picture has some weird things going on IMO. That tee to the upper left... is the left port blocked? Is that just intended to add extra venting, or is there drainage coming into that from left to right?

The tee in the upper right is also odd. Just trying for extra venting?

There is a way to measure the pressures/vacuum in your pipes, other than using the clear p-trap. https://terrylove.com/forums/index....+manometer+tubing&c[users]=Reach4&o=relevance has various posts where I have posted about that.

Thanks for the feed back

The Tee upper left is suppose to be extra venting, it's was that only way I could think of to get a fitting in place with how cramped it was in the corner. And the same for the right side, just more venting.

Is there suppose to be a p-trap in the floor at the bottom of the stack? I'm not sure what you mean.

Right in front of the stack is the toilet (not seen in the photo)

 

[Reach4]

Is there suppose to be a p-trap in the floor at the bottom of the stack? I'm not sure what you mean.

No. I had misunderstood.

The only way I can explain it is, almost like there is too much air coming back from the main drain

I had somehow thought you were saying there was air coming out of the floor drain. Read too fast. I see my mistake. So please ignore my comment about a floor drain. I edited my post to cross that out. A floor drain would have a trap.