Siphoning Diagnosis

[Zane Vaughn]

Trimming a new bathroom currently. Second floor bathroom, dedicated 3” stack. Had to make a couple goofy turns. This was laid out by a plumber, installed by myself (carpenter) and inspected by the county.

Toilet is filling fine, but bowl empties in less than 10 minutes after a flush. No water on the floor. Floor is level. Flange is mounted on top of the tile. Kohler Elliston toilet. Sink trap and shower trap hold water fine and there’s no gurgle. Have done 15 or so bathrooms, but this is the first time this has happened to me.

County requires same size vent out the roof. Haven’t tried really any troubleshooting yet I just wanted to get initial ideas before I pull the toilet, climb up on the roof or rip anything apart.

 

[Zane Vaughn]

Update:

Got on the roof with a hose. Vent is clear. It gobbled five minutes of water at full blast with no issue. Had thought that I could have a nest or something in the 90s but that doesn’t seem to be the case.

 

[Sponsor]

 

[Reach4]

Seems to me that it has to be a cracked toilet.
Is there a flaw showing in this picture, or is that something discarded into the toilet? Does the water drop to the bottom, or does the water stop dropping at some higher point?

 

[Sylvan]

I never would service or install a kohler toilet as I rather have quality /working toilet then going for the "bold look"

I lost count on how many Kohler Rialto toilets I replaced with Gerber or Crane toilets which cost a lot less BUT they do not need a plunger next to them

The Kohler flushmate was another bomb looking to explode IMHO

Toilets must have water visible usually as this is the trap seal

How far away is the vent from the toilet?

 

[Zane Vaughn]

Seems to me that it has to be a cracked toilet.
Is there a flaw showing in this picture, or is that something discarded into the toilet? Does the water drop to the bottom, or does the water stop dropping at some higher point?

Kinda what I was thinking. In the process of pulling it now. We’ve bought three of the same toilet for this remodel but already had to swap a white for a biscuit to match an old crane sink. So I have two toilets waiting in the wings.
Gonna drop in another and cross my fingers.

No visible flaw that I can see from top or bottom and I had a good seal on the flange.

 

[Zane Vaughn]

I never would service or install a kohler toilet as I rather have quality /working toilet then going for the "bold look"

I lost count on how many Kohler Rialto toilets I replaced with Gerber or Crane toilets which cost a lot less BUT they do not need a plunger next to them

The Kohler flushmate was another bomb looking to explode IMHO

Toilets must have water visible usually as this is the trap seal

How far away is the vent from the toilet?

I never would service or install a kohler toilet as I rather have quality /working toilet then going for the "bold look"

I lost count on how many Kohler Rialto toilets I replaced with Gerber or Crane toilets which cost a lot less BUT they do not need a plunger next to them

The Kohler flushmate was another bomb looking to explode IMHO

Toilets must have water visible usually as this is the trap seal

How far away is the vent from the toilet?

Noted. I will keep that in mind in the future. Vent takes off on the wye just before the closet bend. No more than a foot.

 

[Sylvan]

A trap seal can be lost by oscillation meaning wind effect

An example would be air blowing down a vent stack causing the bowels water seal out

Poor venting , such as a toilet above being flushed and it cases back pressure

Capillary action (attraction) such as a a string will drain the trap

 

[Zane Vaughn]

A trap seal can be lost by oscillation meaning wind effect

An example would be air blowing down a vent stack causing the bowels water seal out

Poor venting , such as a toilet above being flushed and it cases back pressure

Capillary action (attraction) such as a a string will drain the trap

That was my fear. Only thing on that stack is a single bathroom group, but thought it could be something atmospheric because the top of the vent is close to the toilet which is the last thing on the line.

Turns out it was a junk bowl. Swapped it out and it’s holding water fine. Bathroom was so swamped with gas it took all day to clear it and I was convinced I had a bad seal. Smelled fine this morning and it’s pushing waste well.

Thanks