[Solved] Unpleasant Sewage Odor from 1960s Sink: Tried Hot Water, Kreta Granules & Enzymes – What's Next?

I live in a block from the beginning of the 60's. For some time the sink has been giving off an unpleasant odor from the sewage system after flushing the tap water. I tried to run hot water for half an hour, then I sprinkled Kreta in granules but it did not help. In the end I used Kreta Bio with enzymes, poured in 100 ml as instructed and left it overnight, then rinsed It seemed that the problem was gone, but after a few days it returned. What's next?

Check the siphon under the sink if it has the right level, maybe you have pushed too much of a pipe inside and there is no level so the air passes through.

Often muck remains in the tubules from the overflow. Sprinkle a mole there, preferably as a solution.

berthold61 wrote:

Check the siphon under the sink if it has the right level, maybe you have pushed too much of a pipe inside and there is no level so the air passes through.

The vertical tube enters 0.5 cm, the horizontal one approx. 3 cm

palmus wrote:

Often muck remains in the tubules from the overflow. Sprinkle a mole there, preferably as a solution.

And how to secure it so that it does not run off?

Htomas wrote:

berthold61 wrote:

Check the siphon under the sink if it has the right level, maybe you have pushed too much of a pipe inside and there is no level so the air passes through.

The vertical tube enters 0.5 cm, the horizontal one approx. 3 cm

I do not know if I understand you correctly, but this tube from the top is to be submerged below the water level by at least 3 cm.

berthold61 wrote:

I do not know if I understand you correctly, but this tube from the top is to be submerged below the water level by at least 3 cm.

Irrelevant. Siphon and it will be so. This chamber is divided inside.

@piracik

Exactly as you're saying.

The solution may not be practical, but I will write. Block the sink with the stopper and the problem will disappear, unless the stench hits the overflow.
Doesn't it smell from other sewage holes? Can you hear gurgling in the siphon? Various things can happen.

Perhaps it is worth cleaning the siphon itself.

@CapitanSTS

This step should be done first.

palmus wrote:

The vertical tube enters 0.5 cm, the horizontal one approx. 3 cm

Vertical too little !!! it must be at least 5 cm below the water level in the siphon - then the buoyant odors from the sewage system will not overcome the liquid.
It is very common that in the sewage riser (there is always a vent pipe above the top floor), for example, a pigeon settles and the gases compress a bit.
5 cm of water = 0.005 bar. 5 m of water = 0.5 bar

If what you write about immersion of the tube made sense, this drawing would be wrong.
The manufacturer states that we can pull the tube as much as 110 mm when the water surface is about 90 mm?
Does he not know how the siphon works?



Added after 30 [seconds]:

ziemek56 wrote:

Vertical too little !!! it must be at least 5 cm below the water level in the siphon - then the buoyant odors from the sewage system will not overcome the liquid.

Htomas wrote:

And how to secure it so that it does not run off?

You're not securing. The thick solution will do its job. You can repeat that later.
I have already seen 3 "modern" sinks, where the water flowing down the drain ran into the overflow from the bottom, then just a few hairs and it's starting to make a nest there ...

This is a drawing - a view. It does not show the interior. You would have this cross-section.
I put some on the drawing and you can see how the water goes.

piracik wrote:

The manufacturer states that we can pull the tube as much as 110 mm when the water surface is about 90 mm

Because that's how much you can extend and maintain the mechanical rigidity of the connection. For the manufacturer, it is a sedimentation tank, and whether it will be a siphon depends on the immersion of the downpipe.

piracik wrote:

This chamber is divided inside.

Yes, the photo above shows another one, and it can be with a partition.
In my apartment, the settlers' chambers are not divided and there is a free passage in the "pear".
I have exactly the ones in the drawing.
The baffle in this model would have to be like a green line and ... it would be a bit tight at outlet 32

ziemek56 wrote:

For the manufacturer, it is a sedimentation tank, and whether it will be a siphon depends on the immersion of the downpipe.

Good. You have a fantasy :)

You see, I don't need a cross-section to infer from the documentation that the manufacturer siphon allows the tube to be pulled out so that its end is about 110 mm above the bottom of the glass siphon if at the same time this height is half the height of the drain, i.e. higher than the water level, a siphon must be structurally provided in the center. For example, through a partition or a tube as in the photo


Settler

did you clean the pipes and the sewer inlet in the wall? hairs etc. often settle there and then it stinks, if you poured plaster into the wash basin, then take it apart carefully and clean it

There is one more, unlikely reason, but still possible: my friend had a faulty wash basin and water was getting between both sides of the ceramic cast (!). The cause of the stench was undetectable until the sink was disassembled and dissected ...
I didn't believe it until he showed me the pictures.

hugonot11 wrote:

did you clean the pipes and the sewer inlet in the wall? hairs etc. often settle there and then it stinks, if you poured plaster into the wash basin, then take it apart carefully and clean it

The problem was probably the transfer. I blocked the sink with a stopper and turned on the hot water for half an hour. And then I remembered that I have K2 foam for cleaning car air conditioning somewhere. I peed, waited, rinsed and it's probably OK. Of course, I unscrewed the siphon and cleaned it thoroughly.

The topic seemed to be resolved, but not quite as it turned out. The slight stench continued to emerge. I put a wire into the sink drain, when I pulled it out, there were gray fragments of some goo stuck on it. Since the screw fastening the siphon inlet could not be moved, I opened it and dismantled the siphon. As the screw in the vice could not be unscrewed, I took it all to a DIY store and it turned out that you had to buy a whole new siphon. I felt sorry for less than PLN 30 and bought it. Having access to the drain from below, I covered it with foil and poured Kreta Bio for a few hours. Then I rinsed. I installed a new siphon, blocked the sink with the plug included in the set and let the water run for several minutes. Then I put the wire in the drain again. This time there was no muck. Smells too. So it looks like the problem is finally solved to the end. But let's wait until tomorrow

A several-year-old washbasin or sink siphon is sometimes worth unscrewing and thoroughly washing all parts, because despite the fact that it cuts off odors from the sewage system, it is / can cause unpleasant odors in itself.