We bought a 1920 house about a year and a half ago and occasionally we can smell a sewer gas odor and I’ve been trying to figure out what the cause is. Whenever we smell it, it’s coming from either the second floor bathroom or the kitchen below it on the first floor. Sometimes it smells bad in the dish washer when I open it up right after running it.
The house was replumbed by the previous owner. It has those red and blue plastic pipes. The sewer pipes (at least in the basement) appear new as well.
Last night, I figured out something new which may be related: when the tub in the second floor bath is stopped, the toilet does not flush well. We had started smelling the odor last night in the bathroom when the toilet wasn’t flushing. My wife took a shower and realized the tub wasn’t draining well and we figured out that the stopper was engaged. After disengaging the stopper, the toilet would flush fine.
I have been looking for a pattern that can explain every time we smell the odor, but nothing seems to fit. Running water to fill traps doesn’t seem to fix anything. I have a couple theories:
- The vents are not done correctly
- There’s a siphoning issue
- There’s a crack in a vent
- Toilet seal is breeched (toilet is slightly wobbly)
Do any of these make sense?
Other notes: the previous owners added 2 bathrooms: one on the first floor and one in the basement that has a pump in the floor to pump waste water up into the sewer line. I don’t know if this is relevant. The kitchen was expanded and the kitchen sink moved. There’s a vent under the sink. I can’t figure out where the vent for the second floor bathroom is. It’s definitely not through the roof and the only think I see outside on the exterior wall is the air vent for the ceiling thing.
Does anyone have an idea what could be going on here? What could be causing the sewer gas smell? And why doesn’t the toilet flush well when the tub is stopped? Is that a telling sign of what the issue is?