Sewer smell

[TimeOnTarget]

Does your septic tank have a filter?

Negative.

 

[VAspeedgoat]

I lived in a house in college that had the hidden floor drain that dried. Filled with water and the same issue. In that particular case what happened was that the drain cover had rusted and wasn't to proper depth into the trap and would let the smell through. It was an older house and the landlord replaced all of them in the basement and that was the end of the sewer smell. It was a great *!?% blocker with girls. I still panic if I get a wiff of sewer!

 

[BackofBeyond]

Any chance you ended up with a loop vent somewhere in the walls of the basement?

 

[OntarioHunter]

Only time I have noticed a sewer smell is after I switch to raisin bran cereal, especially in the morning ... when I first throw back the sheets to crawl out of bed. Also no longer need to turn on the electric blanket at night. Hmmm.

 

[kansasdad]

We had mysterious sewer gas smells in our downstairs that was difficult to identify the source. The smell went away after running the never used shower, so I thought it was just a dry trap. It would still show up and fade away over the next couple of months. Hanging around for a couple of hours to maybe a day or two.

Finally a plumber determined that it was a cracked toilet flange that was allowing gaseous emissions without allowing liquid leakage. New flange and reseat the toilet stool and we’ve been fine ever since.

 

[44hunter45]

Depending on how tight your house is, maybe due to the cold weather, your furnace is working harder and turns on more often. It could possibly be pulling air through your vents/traps even though they have water in them.

Do you have a floor drain somewhere you haven't' looked? Like under a boiler, or water heater?

I have also had smells, and it was always a floor drain that dried out.

Check the floor drain for your furnace condensation. It should have a trickle feed to keep water in the trap.
Mine was backing up last year and while investigating I found an vent riser where the builder had just slipped an 1 1/4 into an 1 1/2 ABS. It had fallen down into the Tee and was blocking the drain.

I fitted it with a glued in 1 1/2 riser and a reducer and no blockage and no more swap smell.

 

[Bullshot]

Finally a plumber determined that it was a cracked toilet flange that was allowing gaseous emissions without allowing liquid leakage. New flange and reseat the toilet stool and we’ve been fine ever since.

I’d also be suspicious about the toilet flange/wax ring, maybe there is some cold expansion/contraction gap allowing gasses to burp.

On a side note, in still, cold weather I often get a waft of sewer smell in my yard, that I believe is caused by sinking air pulling fumes from roof vents downward. I never notice that in the summer.

 

[44hunter45]

I’d also be suspicious about the toilet flange/wax ring, maybe there is some cold expansion/contraction gap allowing gasses to burp.

On a side note, in still, cold weather I often get a waft of sewer smell in my yard, that I believe is caused by sinking air pulling fumes from roof vents downward. I never notice that in the summer.

We have a pond rather than a leech field. A pump lifts the tank outflow up to the pond.
When air conditions are right sometimes smell will drift down the hill toward the house.

 

[LuketheDog]

Alright guys, you’re a group of smart guys so help me out with where to start/ continue my search for why I have a sewer smell in my house.

Every time it gets cold out(today is about -5) I get a sewer smell in My house. My roof vents are not froze over and my traps all have water in them. I’m on a septic system. It started happening about 3 years ago when I finished my basement and installed a full bathroom. The basic plumbing/drains for the basement bathroom had been there for 10 years prior as it was installed in the concrete when the house was built. Obviously the venting for the bathroom was plumbed in at the time of finishing the basement. I’ve read some about the cold air basically creating a down draft and not letting the warm gases escape out the stacks, settling back down the stacks instead. I never have this problem until it gets cold.
Give me your ideas and solutions.

Floor drain in the mechanical room is a common culprit, especially if your humidifier isn't running and the trap dries out. I also found that our basement shower drain trap would either siphon out or dry out and allow septic smell back up into the house. Either tape over that drain when not in use or use the shower more to keep the trap full.

 

[LuketheDog]

When I read sewer smell, this was the first thing that popped in my head , I know , I’m not much help
View attachment 309844

As an American man, this is the first thing that should pop into your head...

 

[Butcher]

I had a similar issue. Ripped out my basement shower and it didn’t get rid if it. I took the toilet out and replaced it with new wax ring. Didn’t fix it either. I put a plug over my toilet drain. So I no longer have the toilet hooked up but its plugged and its fixed. Lol on further investigation it was rhe floor flange, it had a crack in from over tightening

 

[Nick87]

@TimeOnTarget woke up this morning wife told me same thing about a sewer smell coming from the bathroom. Went up on the roof. All 3 vents were completely iced over. Might wanna check that.