We noticed sewer gas coming from a basement bathroom. Made sure all the drain traps were filled with water but the problem persisted. Removed the toilet and saw that the edge of the flange was broken where the closet bolt attaches and that the break extended down about 1/2" down towards the drain. I'm assuming the sewer gas was leaking through this broken area.

I tried gluing the flange back together with some pvc epoxy and a heat gun but that failed.

Our conclusion was that the flange had been broken when it was installed. The plumbing is less than 2 years old.

The gas became noticeable after the septic tank was cleaned and the drain pipe going into the tank was repaired. The repair was necessary because the pipe was separated at a joint and was creating a trap that was evidently filled with water thus preventing gas to come back up the pipe towards the house. Which is why this problem wasn't noticed before.

The flange, besides being glued to the 3" PVC drain pipe is also attached to the concrete floor. The screw/bolts are flush to the flange and appear to be of some special manufacture that requires a special tool to install/remove.

I think the break in the flange that extends toward the drain compounds this problem otherwise maybe a simple flange extender would probably solve the problem.

Will a twist n' set flange fix this problem? If so do I saw off the old flange flush with the floor and then install the new piece? Or should I call a plumber?

Can you take a photo of it and post it ?

2 Photos. The 2nd is a close up of the screw/bolts.

Thanks for posting the photos...

The closet ring is broken in a place that doesn't effect drainage or the way the toilet is attached to the closet ring. In other words, all the important parts are intact. The closet ring is glued OVER the pipe so it should not cause leak when toilet is flushed. You can set toilet over it and ignore the missing part of the closet ring.

Use "fat" wax ring to install toilet. You have to feel it is being compressed when you are setting toilet over it. This will make positive seal. I understand your theory about origins of the smell but doubt the smell came out of that broken closet ring.

It would be hard to remove because it is glued to the pipe. You would have to carefully cut the ring off at around the pipe entrance but leave the Hub of the ring glued to the pipe. I would not attempt to remove it since there is a good chance you would break the pipe itself. Then you could either install closet ring that fits INSIDE the pipe and glue it in. Also, and as you mentioned, you could use "Twist'n'Set" ring.

Milo,

Thanks for the response.

The toilet never leaked but there was a sewer gas problem. Would it help to ensure that the wax ring was pushed down into the broken off area?

Attached is a photo of the broken piece.

Jim

The first picture is oriented with the top of the picture closest to the wall that the toilet is against.

Thank you for the second photo...

As I said in my previous post, the ring is installed on the outside. The way it is broken should not allow sewer gas in. In old houses they didn't use closet rings at all - they set toilets directly over pipe on wax ring and it made positive seal.

If you really feel like you have to remove it - than unscrew the bolts, take a skinny wood chisel, put tip of the chisel between the pipe and closet ring and slowly try to break it off piece by piece. If primer was not used during original installation than you have a chance it will peal off. If not, you will have to cut it off and proceed as I explained above.

But still - my opinion stays: The way it is broken, it should not cause sewer gas to escape to the bathroom. If it was in my house, I would not worry about it...