View Full Version : Water Level in Toilet

03-01-2012, 11:12 AM
I live in an older ranch-style house. The house only has one bathroom, with the typical sink, toilet, tub/shower. The only other thing that drains into the main drainage line is the kitchen sink. Over the last month or so I have noticed that the water level in the toilet bowl seems to be at a lower level than normal. I say "seems" because the other member of the household has not noticed anything, and others who have used the bathroom don't really notice it as an issue either. Since I first started to think the level is down I have been watching the toilet more carefully. What I have noticed happening is, after the toilet is flushed, the bowl fills up to say half way (probably a little less than half). Then after the flush is complete and the water has stopped running the water level in the bowl goes down maybe an inch or so and then levels off after a couple of minutes. During the time the water level is dropping I can hear water trickling, and it sounds to me like it is going down the drain. After it levels off the water pretty much stays there, although if it's left alone for awhile, like overnight, it maybe goes down a little more (but this could just be my eyes playing tricks on me). The toilet flushes just fine; no backups or need to flush a 2nd time (I hope I don't jinx myself). The toilet is a Kohler Cimarron 1.6 GPF model, which was installed a little over two years ago.

I've been searching around on the Internet for this issue, and most answers point to one of three things: 1. A blocked or partially blocked drain vent. From what I have read this issue would most likely affect other drains, but at least so far I am not seeing this. The sinks and tub/shower continue to drain just fine. 2. A crack in the toilet. As I mentioned, the water seems to trickle down the drain and it does level off eventually. I have not noticed any water on the floor in the bathroom. There is some evidence of water stains looking up from the basement to the sub-floor of the bathroom, but I know for sure some of the stains are old and I can't really see anything new. Based on experience from other leaks through the floor I'm pretty sure I would see actual dripping water somewhere in the basement. 3. Some issue with the flapper or other part in the tank. I haven't really checked this yet, but would the water fill, drain, and then level off it there was an issue in the tank, or am I misunderstanding the symptoms of these problems?

I don't mind trying some DIY steps, but my biggest fear is that there are some old water / drain pipes involved here and I don't want to do anything that might make matters worse, or cause another bigger issue. On the other hand I don't want to call in a plumber if it is something that I can (easily) address myself.

So, does anyone have any ideas of where the problem really lies, and if / how I can fix it?

Thanks in advance,

03-01-2012, 11:22 AM
Dental Floss in the trapway can wick the water out of the bowl.

03-01-2012, 11:31 AM
Thanks for the reply Terry. I know that I *never* throw dental floss down the toilet. Can't speak for the other person in the house though. How would I go about checking this? (Sorry, I'm a novice with this stuff.)

03-01-2012, 02:05 PM
A toilet auger, if you were lucky, might catch dental floss IF it was there, but no guarantees. A toilet bowl is like a cup filled to overflowing. During the refill process, the water that goes into the overflow pipe in the tank runs down to refill the bowl. You cannot overfill the bowl unless there's a clog downstream as once you reach the top of the weir (think dam in a stream), the water runs over the dam. Now, it can take a moment to stabilize. High winds can cause some pressure variations in the venting system and cause the water to rock back and forth a little, and that can cause some to slop over the weir, leaving the bowl slightly less full, but there's a limit on how much you can rock the water and how much sloshes over the weir and down the drain.

03-01-2012, 06:13 PM
Also, if you flush a nearby toilet, it can lower the water in a bowl depending on how it's been plumbed.

03-02-2012, 07:23 AM
Thanks for the responses. As I mentioned in my original post, it's a small house with only one bathroom / toilet, so definitely not a nearby toilet causing the issue.

I've been doing some more searching around regarding the model toilet I own and I'm starting to think the water level may just be the way this thing is supposed to be. I'm beginning to second guess myself as to whether or not the level actually used to be higher, and whether or not the current level is really a problem. The toilet continues to flush just fine, so I'm almost to the point of saying "if it ain't broke, don't fix it". Just concerned that it could be an indication of a greater problem and if I don't address it now I will run into bigger problems down the road.

03-02-2012, 08:05 AM
You can find out by slowly adding water to the bowl. If the level goes up, it isn't refilling properly or something is pulling the water out (venting issues, crack, etc.). If the level doesn't go up, the bowl is as full as it will ever get and there is no problem.