Complicated Sewer Smell

[Gilo]

https://photos.app.goo.gl/D7QNb8PD8MRmaaNj8

Hey everyone, so we have a basement bathroom and main bathroom. The basement is only under part of the house. Under the rest of the house, including the main bathroom, is a crawl space.

A few months ago we noticed a sewer smell coming from the main bathroom every time the basement bathroom sump pump fired. We cleaned out the vent pipes which didn't help. I went into the crawl space and noticed the toilet wax seal was leaking. I fixed that and the smell disappeared for a week and is now strongly back. I can't find any other water leaks in the crawl space.

The smell is not coming out of the bathroom any more but clearly the crawl space. There is this pipe coming up from the sewer line downstream that has this gap, see picture. It is hard to localize the smell but could this be the source? What is the purpose of the gap, to bring air into the sewer line? I think this pipe ultimately vents to the roof. Also could a partially clogged sewer line cause this? No water is backing up anywhere that I can tell.

I am trying to avoid a smoke test because of the cost but may have to do one ultimately.

 

[Geofd]

I cant see tne pics im sure its my computer,but if you have a gap in your sewer/vent piping fix that 1st then see what happens

 

[Diehard]

From what it sounds and looks like, that gap is a joint that should be connected with NO gap.
That's likely the source of the smell.
Reconnect it.

 

[Gilo]

It's weird, it seems purposeful, the gap. Is the link working? If not, I can try to share another way

 

[Diehard]

It appears pretty obvious that the joint came apart.

If there is no trap between that joint you're showing and the sewer or vent pipe, that's where the smell is coming from.

However it may have happened, that joint simply came apart.

 

[Jeff Handy]

Diehard is right.

Just loosen that hose clamp, pull the pieces back together, and firmly tighten the hose clamp.

If they won’t reach, then the pipes have settled or shifted, but it should be easy to extend them to reach each other, and keep the stink contained in the vent where it belongs.

 

[Gilo]

Thanks everyone! I will do it this week.