I am a maintenance supervisor and I have a resident that is complaining about a "sewer gas smell" in her apartment but she only smells it between 6:00pm to 8:00pm. I have looked at all drains and reset the toilet with a double wax seal an set the toilet in plaster of paris. I have looked at everything that I can think of. I am looking for all and any suggestions.

plumbing smoke test..
[www.google.com]

Any recent work in her apt, or the one below, above or next door to her that might account for the odor? Any new tenants near her that might be doing something different? Does her kitchen stove have a vented hood or her bathroom have a ceiling exhaust fan unit that might be letting in odors from outside the apt? What about the washing machine drain pipe trap? What about common plumbing drains between the wall to next door apt, maybe an oversized hole in the wall where the pipe goes thru, letting in odors from a dry drain trap next door. If any apt around her's are empty might want to check the drain traps in them.

Might be good to arrange to visit her apt around that time of evening and see first-hand what she is sensing. Maybe you can pinpoint the source.



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Is someone in the building using cleaning acids in their waste lines?

Best Wishes

Do the units have individual heat/A/C units? That is probably about the time they turn on the heat in the morning.



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They do have individual heat units. When the heat is on that is when it dissipates.

Do I have to pull toilets and block off sewer lines to perform this test? I have never done this. The buildings are 10 unit buildings.

No, leave the toilets as they are. The water in the trap will prevent the smoke from exiting the bowl. You might even find a faulty wax seal or 2 if the smoke starts coming out from between the bowl and the floor. If smoke can escape so can sewer odors.

I would check to see if you have any plumbing vents near windows or HVAC intake air openings. If this is the case you can try extending the vent up a couple of feet. Sometimes, barometric pressure can push sewer gasses down low to the ground, into the window and/or door openings or HVAC vents.

To verify that it is actually sewer gas, buy a combustible gas detector. These can be purchased for around the $150 to the $300 dollar mark. Since sewer gas consists of hydrogen sulfide and methane the combustible gas detector can be used. Your tenant may think they smell "sewer gas" when it could be something totally different, like smelling garbage. Check all around your tenant's apartment, check around all of the AC vents, around windows, around the bases of toilets, and around plumbing traps. This little tool will save you the aggravation of pulling toilets and replacing p-traps unnecessarily.

Make sure all of the p-traps have water in them. Do not overlook any floor drains that may be in mechanical closets.

The smoke test will show you if you have any openings or breaks in your drain lines or plumbing vents. Just be prepared for a room full of smoke if there is a break in the piping. A smoke test uses theatrical smoke, just like you would see at a concert or sporting event. Essentially it's a fog machine on steroids. Leave all of your plumbing fixtures in place when performing this test. Its probably best to call in a company for this test.

If you have plumbing vents near AC intake air openings, they could be pulling in sewer gas when your AC air handlers turn on. You would not always notice this issue, the barometric pressure and outside conditions would have to be just right.



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Maybe it's not sewer smell. Maybe it's neighbors smoking some funny stuff. Have you been in there during those hours?

Why horrible sewage gas smell from ejector pump in basement only when it's very hot - humid outside?
No bad smell in winter or on cool, low humidity days.
Please help?