Ikea Siphon Atlant venting/air release problem. It smells bad

Hello Ikea fans, I am actually a total Ikea user, but with the siphon Atlant I have made a mistake: Under the kitchen sink I wanted to create space for 3 waste separation bins and built the entire siphon system Atlant accordingly slim. But if someone one floor below, for example, flushes the toilet or lets the shower drain, a vacuum pulls the water out of the siphon and it smells throughout the kitchen. It doesn't happen all the time, but quite often. We live in a three-family house and we are on the bottom floor (ground floor and basement), and it could also be a neighbor above us who lets the bathtub drain and thus "sucks out" the siphon. It then smells better but still somehow ... strange. Maybe you have a tip, Ikea service hotline no longer really exists, right? What did I do wrong? What do you think? I would be happy if someone shows their expertise. Best regards, Toll

Hello
I am not a plumber, but I think the siphon is too high, however I can still ask my plumber.

regards bergpriv

Hi!
I am also not a plumber, but you have to make sure that the siphon is positioned vertically and not tilted like in your case.
Regards

Hi!
I’m also not a plumber, but you have to make sure that the siphon is positioned vertically and not tilted like yours.
Regards

Yes, I will try to get the siphon into the horizontal position. NORMALLY, the siphon is also deeper than the outgoing sewer pipe, but the user manual did not require this; rather, it was the opposite, crossed out as an option.

Do you think straightening the siphon will really be enough? Should that already solve my problem? There are more difficult ones.
Best regards, Uwe

Hi, not horizontal but vertical, so that the water level, which practically forms the water seal, is equally "thick" at every point. If you tilt your siphon sideways, the water (which is always horizontal) on one side is quite "thin," so that with slight pressure differences, the gases (bad sewer air) can escape. Regards

Hi, not horizontal but vertical, so that the water level, which practically forms the trap seal, is equally "thick" at every point. If you tilt your siphon to the side, the water (which is always horizontal) is quite "thin" on one side so that with slight pressure differences, gases (bad sewer air) can escape. Regards

I did it! And - it didn't help at all. It still smells terrible. I'm calling the plumber now. Thanks for your effort. Best regards, Toll