water leaving toilet bowl

[franktank]

I had trouble with a old toilet loosing water in the bowl. The toilet was not running nor did it have any odor. I just replaced the old toilet with a brand new one and it is doing the same thing, only a little water will remain in the bowl. I have a toilet back to back with this one and that one is just fine. I have changed wax rings, added a ring and now am completely stumped!! I have asked many plumbers and all say the same thing.....never heard of that one before. Any suggestions??
Frank

[pushkins]

Does the water disappear from the toilet after you have flushed the other one ? or is it a slow decline in the level when no other toilet is flushed?

[ABP]

Sounds to me like a vent problem. Think of it this way, if you have ever put oil in your car with one of these new plastic quart containers you will notice that when you turn it upside down the oil comes out yes, BUT you will also notice that it "Glugs". This is because you are creating what is known as "Negitive Pressure" or in laymans terms, a vacume, now if you punch a hole in the bottom of the container, the oil comes out smooth and steady, this is because you broke the vacume and are now getting equal amounts of air in for amounts of liquid out. This holds true with your septic system too. What I would do is fill the offending bowl with water (Very slowly ) Once it is full, have someone flush the other toilet and see if the water "Moves" at all. The slightest movement no matter how little may indicate that the system is trying to pull air through the toilet. If the other toilet is not having an afect on it, then make sure the offending toilet is again full and try running the washer machine (As this is usualy suspect #2) If nothing happens, again make sure the toilet is full, fill your bath tub and kitchen sink, once full, have some one empty them at the same time and see it this makes the water move in the toilet. Come back with your results and I can guid you then to a repair

[pushkins]

Ahhhh I remember the days of a beer can, all shook up and a hole in the bottom just to help it go down, mostly bad memories, but memories just the same.

(layman terms for what probably is the problem)

[Phelps]

But, what is odd is why the other toilet that is back to back and presumably teed into the other toilet, is not doing the same thing. The fact that a replacement toilet does it almost...almost...eliminates the possibility of a crack in the trap of the toilet. Yet, we know SOMEthing is causing this. This is an interesting one alright.

[LazyPup]

I agree with ABP,,it sounds like both toilets are Wye'd into a common waste arm and probably that line extends a fair distance to the vent. In this configuration as one toilet flushes it will push the air down the line leaving a negative air pressure behind which is effecting the opposite toilet.

We must also consider that the toilet in question is a new 1.6gpf while the opposite one is an older 3.5 or perhaps 4.5gpf. This means the normal water level in the bowl of the new one is also much lower so even a small loss of water would be more noticable.

The solution would be to install a vent as close as possible to the point where the two waste arms are connected to each other.

[ABP]

AHH YESS the beer can memories! Just exacly when did those days end I wonder
Phelps, yes and no, I mean it really depends on exacly where the other toilet ties in at, above or below (Up or down hill) from the other, if it is downhill, why then yes it would attempt to pull air in from any were uphill from that point and since the offending toilet is so close, logic would say it is pulling air from within that toilet. Another thing we must consider is how much of the line is clogged, I mean the side walls of the pipe will build up with "Gunk" over a period of time there by reducing the inside diameter of the pipe. When this happens, it takes less volume of water to "Load" the main line ther by causing the vacume. Simple solution if it is that is to ream out the line. Now if you want to talk about a strange case of toilet problems, I once had a toilet that would fill completely to the brim and slowly decend, this did not happen before the bathroom remodel, just after, and there were about 5 different plumbers who could not figure out why, I even replaced the toilet, reamed the line and installed a vent close by, poured a 5 gallon bucket of water straight down the pipe with the toilet removed and the water went straight down, no problem, re install toilet, fills to the top and slowly desends. Figure that one, it still has me baffled, and yes, I sat the toilet outside on blocks, filled the tank, flushed, water ran just fine.

[Phelps]

ABP,

Per the last several lines of your post regarding your toilet; you still have that toilet hooked with the same problem going on? Do you lay in bed at night, wondering? This can be both therapeutic (lets your mind be occupied by something of a challenge), and a curse (being driven nuts by a problem you can't solve).

The fact you say it flushes outside up on blocks means it surely has to do with the waste or vent line, regardles of the bucket test, IMO. Did you pour the water from the bucket in the toilet as fast as what the toilet could flush it out? But regardless, don't forget that without the toilet hooked up, you are conducting a test without a trap (the toilet itself contains the trap)...meaning, it sounds like a vent problem if you ask me, because if the waste line allows the same volume of water, in the same amount of time, from the bucket, down the line...and the toilet flushes fine when not hooked up...it seems like the only thing it COULD be is the venting, as that is the only thing that can change by putting the toilet back in place (with there now being a trap in the line).

[Phelps]

ABP,

Oops, duplicate post (I now erased) due to me talking to someone in the other room.

[ABP]

Yes, I tried the bucket test with and without the toilet connected, and yes I installed a new vent as close as possible, someone told me once it may be that when they remodled they used a pvc test flange with a knock out and the knock out may have fallen in the pipe, and when water tried to run through it tilted the jamed disk sideways blocking the water were as the snake would simply slide under it. It's the only thing so far that makes sense. And no, I do not lose any sleep over it as we win some, and lose some.

Back to the problem at hand, franktank, had you tried it yet and what happened?

[mrcaptainbob]

Extra work...

I'd lightly stretch some saran wrap across that hole and seal it. Then observe if it looks like it wants to get sucked in when the other toilet is flushed. That would certainly prove the venturi issue....

[pushkins]

great idea !

[karolion]

atoh episode #323

I have seen a problem like this fixed on Ask This Old House. In this episode the plumbing expert on the show brings aportable video monitor connected to a diagnostic camera, which is mounted on a flexible motorized tube, and goes down the vent stack looking for debris, dead animals, bird nests, etc. The camera is like an endoscope used in surgical procedures named with the suffix -oscopy. After, the other hosts of the show ask can this clogged vent stack be prevented and he explains that in regions where there may be freezing conditions if water was to freeze over a device made to shelter the vent stack(like you may see on a chimney) your house would build up with the pressure of unvented air and the weakest link in that chain would burst to release the air pressure. You may be able to see into the vent stack yourself with a good light source if the vent stack serves no more than 2 stories(even that is pushing it as this vent pipe may be 3-4" in diameter, up to 6" at the most;I am guesstimating here). I have this episode stored on my DVR, so if you know how to record it to a writeable cd I could e-mail it to you.

[Piper]

I know this thread is four months old, but I have to ask. Any of you ever heard of capillary action. Probably a mop string or some type of cloth or string stuck in a position over the trap wier in the closet slowly syphoning the water out.