Location: Orlando FL. City sewer, PVC mainline, 30-year old house. Toilet backing up is the one closest to the cleanout. Toilet, sink and tub are backing up into each other. Disclaimer, I am not a DIY-er.


One toilet started repeatedly backing up. Plumber snaked and used camera. There was a soft clog very hard to clear out. Afterward, I was able to watch the camera follow the entire line out to the cleanout and it was completely clear: no roots, no other obstructions, no breaks. Clean as a whistle.

Two weeks later, toilet experienced same issue. I used Green Gobbler and it cleared out. Two weeks after that, same issue again. Green Gobbler is not resolving the issue.

Water level rises upon flushing and only slowly goes down, after 6-8 hours. Flushing causes poopy water and mostly-dissolved toilet paper to rise into tub. Running water into the adjacent sink causes vigorous, large air bubbles in toilet. Then clear water gushes into the tub. Tub drains only very slowly--after 6-8 hours.

Other toilet in the house--much further away--is not experiencing issues, although same amount of poop/toilet paper goes into both.

Next input down the line (going towards the street) from the affected bathroom (kitchen sink) also has no issues. So the clogging appears to be between the bathroom fixtures and the kitchen sink.

Inputs:
I'm the only one who uses the toilet so I can state with certainty nothing unusual is going into the affected toilet. No flushable wipes, feminine products, no food/grease, no hair/dental floss, etc. Quantity/size of poop is not excessive and is the same as what goes into the other toilet, which has no problems. I use average amounts of single-ply Angel Soft septic-friendly toilet paper and flush between wiping.

Timeline:
* Original toilets in the house were 2+gallon. Never had any problems.
* Replaced both about 5 years ago with 1.6-gallon flush.
* Had problems with the other toilet backing up about a year after, remedied by installing pressure-assist toilet. It's been fine ever since.

February 2023: New roof/roof vents installed.
March 2023: Clogging problem started happening.
May 2023: The toilet in the now-affected bathroom was a 1.6 modified to use more water to flush and it worked fine, but the modification broke and toilet was replaced with the same pressure-assist toilet as in the other bathroom, which has been working fine for several years.
June 2023: Serious, repeated problems started.


Theories:
The same amount of toilet paper/poop goes into both toilets, but only one has a problem. Everything was working fine until recently. Since roof and new toilet were installed within a few months of each other....can't determine which one it might be related to (if either).

Theory 1: Pressure-assist toilet is too robust and, when there isn't enough water from the lower-flow flush to completely fill the pipe. This causes the water to overshoot the waste…which eventually builds up. Although, the same pressure assist toilet/pipe size exists in the master bathroom and there isn't a problem there. So maybe that's not it.

Theory 2: Roof vent blockage. I don't have the ability to get up on the roof myself to look at the vent, so need to get someone to do that.

I've spent over $600 getting this unblocked once. I don't want to spend a bunch more again and have it not resolve the problem permanently.

Anyone have any useful input?

Replace the toilet with the same model as the other that gives no problem.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

"Plumber snaked and used camera"

Where was the snaking done? Did plumber pull toilet to snake and cam? Or from the roof? If from the roof then roof blockage is unlikely. Is there a cleanout on the vent above or below the drain connection? Difficult to see all the way down a roof vent even with a flashlight to determine if it's blocked.



Edited 1 times.

if the plumber cleared the blockage and the video showed a clean pipe, then it seems impossible for it to clog again in two weeks.

get someone on the roof to be sure Bird poop is not blocking air from entering the vent pipe. Put a garden hose with a balloon that has a hole in the end to blow out the vent but be careful to not overdo it. Be able to tell your helper to turn off the water very quickly if necessary.

its hard to believe that the vent is blocked.
he said he cleared the stoppage with a chemical but it came back two weeks later.
a blocked vent would not do that.