Toilet bowl slowly leaks water

[Cburdick1]

Hello plumbing experts,

We have a toilet in a second floor bathroom that slowly loses water from the bowl. After flushing and allowing the water in the bowl to come back to normal, the water level slowly goes down over the course of a few hours until stinky air begins to come out of the toilet.

Some additional facts:

This doesn't happen to any other toilets.

I thought it might be a clogged vent, and pressure causing water to be sucked out of this toilet. However, when other toilets on the same vent are flushed, the water level in the suspect toilet doesn't move. Running shower / taps on the same vent don't do anything either.

There is no evidence that the toilet is leaking into the house as there are no water stains, drips etc to indicate a leak.

All of this leads me to believe that the toilet is defective and is somehow leaking water down the pipe.

Any advice would be appreciated.

 

[FullySprinklered]

Have you had the rooter man out lately?

 

[Sponsor]

 

[Cburdick1]

Have you had the rooter man out lately?

We had a plumber come out and snake the toilet, didn't find any blockages. He was mystified. Think s the toilet might need to be replaced, that it is just leaking water down the pipe.

I did notice just a minute ago that the water in the toilet is moving up and down (no other water running in the house), but it is a super windy day. Could that be the problem?

 

[FullySprinklered]

Is this a free standing house?

 

[FullySprinklered]

I've had two situations were the toilet bowl emptied itself. One was in a basement barroom in a ladies room where there were four stalls. Flush toilet #1 and step over one stall and watch the water disappear from toilet #2. This was a case of bad venting as near as I could determine.

Second situation, a recently rooted house had a toilet that would not hold water in the bowl. The water would stay a while if there was paper involved. I did some troubleshooting and came up with nothing. Pulled the toilet and flipped it over and found that a hole had been knocked in the bottom of the trap in the toilet, presumably by rooter therapy. Replaced the toilet, solved the problem.

 

[Gary Swart]

The problem has to be in the toilet bowl. Any leak from the tank would not affect the bowl and would automatically cause the tank to refill. I'd suggest you pull the toilet and look for a crack that would allow the bowl to lose water. Even if you can't find a crack, I'm pretty sure there is one so the solution is a new toilet. If you find a crack, don't waste you time trying to fix it.

 

[Jadnashua]

A super windy day could cause a little loss, but not (at least from my experience) enough to drain it. Positive and negative pressure can cause the water to rock a little bit as it changes, and since the outlet of the toilet is like a teapot...a little bit can slosh out the spout, but there are limits. A little bit of this is fairly normal, but may also be a sign that the height and location of your vent pipe on the roof may not be ideal. If it happens when you drain something else in the house, that's an indication of venting problems.