Is this a manufacturer defect in design? This toilet is new, but was missing the flush valve. We used the newly replaced flush valve from the old toilet. Inside the tank of this toilet is a rectangle fill box with the 1/8" tube to fill it as the tank fills, water also goes into the bowl. If we set the flush valve to turn off at the water level in the tank, the bowl does not fill up. BUT, if I set the valve to run longer, the tank water spills over into the black box and fills the tank. I just have to determine when to turn the valve off at the level of the bowl I want -- but, it doesn't seem to stay consistent. What the heck? Is Kohler's water saving idea to keep no water in the bowl, but have a HUGE flapper to let the tank water whoosh out faster sucking everything in the bathroom with it?

I like the flush, but I hate the spoonful of water in the bottom of the bowl -- the bowl dirties and smells quickly. Maybe I should direct my comments to Kohler directly as I think this is a manufacturer design. My husband and I are actually arguing over this -- he says it's the wrong flush valve. I say the valve is universal and doesn't have anything to do with how the bowl holds water, that it's because of the black fill box. Ideas? Thanks!

Upon further research into this commode, it appears to be a Class 5 - Kohler, K-4634. I was incorrect in my terminology -- it is the FILL VALVE that was replaced with a low profile mechanism. Like this: http://www.homefixitparts.com/plumbing/P2-04-198A.php?part=P2-04-198A&dept=Plumbing

It has a screw adjustment that turns the water inlet on to allow more water into the tank. If I turn the screw to make it run longer, the bowl fills up because the tank is overflowing into the flush valve "box".

This fill valve has no other parts/floats, only a fill tube that clips to the FLUSH VALVE (now I understand which is which, hahaha) The flush valve has the large flapper (I guess that is why it is considered Class 5) and the fill box is rectangle. (see here: http://www.homefixitparts.com/plumbing/P2-04-722.php?part=P2-04-722&dept=Plumbing

In any case, upon more discussion with my husband, and I noticed this a few hours later, the bowl DOES in fact leak down. I think we have two issues.. one, incorrect fill valve not putting enough water into the bowl, and two, a leak down problem.

Dang... it's a nice commode, but I guess I'll have to live with it, unless someone wants to start a class action suit since this seems to be a common manufacturer defect. Thank you for your time, of course, if I'm wrong in any of my findings, I greatly appreciate more feedback. :o)

OH, and we can't return it because #1- I got it from a friend doing a remodel, she didn't like the chip on the front edge of the base (does not leak there, does not affect the toilet).. I bet she didn't like that it only held a teaspoon full of water. (exaggeration, about a cup and a half). #2 - It sat in my garage for over a year before we installed it.