Help - Sewage smell coming from kitchen sink during showers

[gbp1s]

Hello,

I have a kitchen and bathroom that shares plumbing/drains from a common wall. Every few weeks, my tenant has complained of a sewage smell that seeps out of the kitchen sink when someone is showering in the adjacent room. There is no odor seeping into the bathroom. The kitchen odor appears first thing in the morning or the evenings.

I've checked (and done) the following things to troubleshoot but cannot seem to get rid of the issue.

1) Check and snaked vent pipe along connecting wall - all is clear
2) Kitchen P-trap is clear and working as expected. I see water being trapped (using a clear p-trap connector) to keep the sewage odors from the main drain. I also cleaned out all the piping underneath the sink.
3) Bathroom P-trap is clear and working as expected.

Anyone have ideas of what is causing the smell? I'm ready to call a plumber but would like to understand what the issue might be before hiring one. Any help would be greatly appreciated.

Kevin

 

[dschae1]

Is there a garbage disposal in the mix? If you can post a picture of the pipes under the sink, it might help to identify the issue. A P-Trap with water in it indicates it is not coming from the kitchen sink btw, unless the water is backing up into the sink somehow.

 

[gbp1s]

No garbage disposal in this mix. I took apart and cleaned all the inside of all piping leading up to the p-trap. Here's a pix

 

[Mr_David]

Sewer odors can be difficult to locate even when I am actually in the room. Something an experienced eye might see that you don't.
Is the piping all original are is something added in to an existing system and hidden in the walls. Is the drains and vent really old like cast iron.
Can you draw a simple sketch of how you think it might be plumbed?

 

[gbp1s]

Thanks for the replies. No garbage disposal in the mix and there's no new piping from original construction. I've tried to post an image but it is not showing up. Let me try again.

 

[gbp1s]

Here's a quick shot of the cabinet base. I just replaced both sink strainer/body yesterday (not shown in this picture) and even cleaned the inner lining of the pipes leading up the the p-trap. The p-trap is clear PVC and shows the water sitting inside the trap.

 

[gbp1s]

The smells resonates on the right side. The tenant was using a wire mesh strainer on this side so perhaps, the odor was leaking out ? The left drain was using the traditional strainer and she didn't complain about any odors. Since the drain/strainer bodies were pretty old, I swapped them all out for new ones.

 

[SHEPLMBR]

The strainer shouldn't matter. You should not be getting smell regardless if there is a strainer in it or not.

 

[gbp1s]

Anyone out there with suggestions with what I can investigate as a probable cause? Still having issues. Just to note, the bathroom sink and the tub sits on the other side of the wall where the kitchen sink is located. Perhaps, there is not adequate draining on the tub side and the water is backing up? I'm stumped...

 

[SHEPLMBR]

The problem could be a faulty vent in the wall. As stated earlier those kinds of smells can be hard to trace. Is this a condo or a house?

 

[gbp1s]

This is a single story home.

@SHEPLMBR - What do you mean by faulty vent? Could it be cracked or clogged - is that you are thinking? I don't think it is clogged as I ran a hose from the roof vent. Drained without issues.

I was back at the property yesterday and snaked the bath tub. The drain was running without issue but the tenant mentioned that it was slower to drain water out in the last two days. I ended up pulling out a nice wad of hair and pipe scum from the overflow cover.

This had me rethinking the odor issue... The tenant complains that odor comes from the kitchen within 5-10 minutes of when someone showers. Could it be that water backs up from the shower drain due to this hair clog and causes the gases inside the pipe to seep out of the kitchen sink?

The tub drain was working OK prior to snaking it. It drains great now! Hopefully, this was the culprit...