I just moved to China about a month ago to live with my relatives in an apartment complex on the 16th floor. Now, there has been a sulfur problem near their washing machine, and sometimes their bathroom too.

What happens is that randomly, the smell of sulfur starts spreading around the washing machine and eventually stinks up the whole apartment. The solution to getting rid of the sulfur has been doing laundry. Once we do a load of laundry, the smell of sulfur goes away.

This leads us to believe that there is some pre existing chemicals in the water pipes. And that everytime the upstairs apartment (17th floor) uses the water pipes, it somehow pushes the sulfur into the pipes near our laundry machine. (The people on the 17th floor moved in last month as well. Before they moved in, there was never a sulfur problem). Currently, the only way to rid of this smell is push the smell further down by washing clothes.

How can we fix this sulfur problem? Washing clothes is only a temporary solution, but sometimes the sulfur comes back immediately after the load of laundry is finished.

Any information about the causes or solution to this problem would be greatly appreciated.

EDIT: Our clothes are not washed with sulfur contaminated water. Honestly I have no idea what exactly is going on with this sulfur, because using the washing machine makes the smell go away, but the sulfur isn't actually in the water the machine uses.

EDIT 2 : Keep in mind this is in China. This stuff looks bootleg. Here is a brief description followed by pictures. The laundry machine is in the corner of the bedroom. The washing machine has a small dark gray hose that outputs the water. Then there is a white tube sticking out of the ground that is the building sewage. All that we do right now is stick the gray hose into the white tube. We tried stuffing the tube with towels when we weren't washing anything, but the sulfur smell still got through.

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  • No Experience here, but it sounds so interesting I tried google.. maybe this helps sheboyganhomeinspector.com/helpful-links/solutions/…
    – Hightower
    Nov 13, 2013 at 6:16
  • Interesting but terrible problem lol. And a lot of google results say to call the apartment or water services, but this is China and they won't do nothing about it. I have to figure out a solution that doesn't involve them. I'm thinking the cause now is bacteria and the solution is some sort of chlorine filter.
    – krikara
    Nov 13, 2013 at 6:39
  • I might suspect you're getting the sulfurous smell from the sewer connection. In most places there would be a gas trap (dip in pipe) to prevent gas coming from there, but I don't know about your building.
    – mgkrebbs
    Nov 13, 2013 at 7:08
  • Oh I forgot to say that the guys on the 17th floor moved in last month too. Before they moved in, there was never a sulfur problem.
    – krikara
    Nov 13, 2013 at 7:29

1 Answer 1


Your problem is the sewer, not the "fresh" water.

Activity on another floor is almost certainly sucking water out of the sewer trap at your laundry and/or bathroom sink. The dry trap then has no resistance to rising sewer gas. Doing laundry fills the trap back up. Here's what it might look like in the wall behind your laundry machine. For proper operation the U shaped part must be full of water at all times:

plumbing trap

We're talking China, so shoddy design or construction are a possibility. If the sewer trap is not vented, or is S shaped rather than P shaped ,it is vulnerable to siphoning dry. See https://en.wikipedia.org/wiki/Trap_(plumbing)

Test this next time you have the smell. Slowly pour about 1 liter of fresh clean water down into the drains near the laundry, and see if the smell starts to dissipate.

You can fix this by crudely mounting a second waste trap between the washer and the building's trap. This could even include an "automatic air admittance valve" just to act as a vent without the need to penetrate the roof or reach a window.

  • Can we rule out that it isn't the water pipes going into the Laundry machine since the clothes that are washed are fine? This means that it has to be the water going out of the washing machine, which is the pipes?
    – krikara
    Nov 13, 2013 at 7:53
  • 1
    And by pipes, I mean sewage pipes. Also, if this is indeed the problem, how can I fix it? Do I need a new trap entirely? If I understand this correctly, then that means there would be a leak in this pipe at the bottom of the U, letting the water get out and the gas get back up.
    – krikara
    Nov 13, 2013 at 8:05
  • @krikara: it may not be a leak in the trap, it may be that the waste-water system is badly designed and that the passage of waste water from other apartments through a communal outlet pipe elsewhere is causing low pressure that causes water in your trap to be sucked out, the trap is designed to hold water to block smells coming up your waste-water pipes. The communal outlet pipe may have a blocked or inadequate external air vent. It might help to fit your own external air vent downstream of the washer outlet trap. Nov 13, 2013 at 12:11
  • It's not just a matter of an unpleasant smell -- sewer gas can be flammable, so this could be a safety hazard if sewer gas is backing up into the house. The "sulfur" smell could be hydrogen sulfide, which is flammable -- it's commonly described as smelling like "rotten eggs".
    – Johnny
    Nov 13, 2013 at 18:53
  • 1
    @krikara warning: that can of great stuff will clog about 2 hours after you use it! I was wrong when I said it would not solve the problem. I should have written "it will not solve your problem" then "it would also lead to flooding or backups in the washer". The washer hose is loosely placed in the drain hole for a reason: air admittance.
    – Bryce
    Nov 24, 2013 at 2:25

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