Hmm.. very good point - where it goes into an elbow, it may have pulled open or broken at the top from settling.
I guess the question is - is this a trickle, or small leak or does it look like a whole big pipe emptied at once through the fixture? the former is a small leak. If the latter, then a gush out of a truncated stack.
When it goes, the entire toilet empties all at once. It is not a trickle. I really think the venting explains it. It may be combined with a clogg that suddenly releases. My wife said that my daughter had been stuffing toilet paper down that sink the other day.
I think you win the thread. It’s the first thing we did, because I knew we were due anyway and cost wise it beats everything. It’s a bit strange that this happens on the second floor first rather than the first.
:dubious:
Occurs “once in a blue moon.”
Bubbles rising up the toilet.
Gurgling noises.
Self flushing toilet.
Liquid seeping onto the first floor.
…
Sounds like your plumbing is possessed by a ghost or demon.
Guess it’s time to call the Ghost Busters or an exorcist.
:eek:
Bonus points if you manage to get Keanu Reeves to do the job.
Well, best of luck to your plumbing issues.
d(^.^)
OK, so it sounds like your overfull septic tank fills with (generated) gas until it blows. At first bubbles come out the drains. One big powerful overpressure lets go, it forces the slug of water in an improperly slanted drain uphill. The water reaches a leak in the top of an elbow joint, oozing into the ceiling and out the light fixture.
Eventually the bubble pushes out (to a vent or out the toilet or drain) outbound pressure releases, and the slug of water goes or is sucked downhill. Likely due to bad venting, a big slug of water going down sucks the water out of the uphill toilet above it.
Check the toilet is properly vented close by; and that a bird has not built a nest on the vent pipe top.
Sounds like a poltergeist to me.