About 5 months ago I bought two of the above mentioned toilets. A few days ago I noticed that both tanks were losing water slowly over a 90 minute period of time causing the tanks to turn on and fill about an inch to top off. I couldn't see anything wrong with either but supposed that water was getting past the flappers. Anyway I called a plumber, and he installed another flapper I had bought called "korky, which is designed to fit the cadet3 American standard." It seemed to work on one toilet, but not the other. The other toilet is still leaking.

Now the plumber noted that the water coming into the tanks was quite cold, and that perhaps that was causing the rubber on the flappers to stiffen slightly. Still, with two identical toilets, both new the korky seems to be working fine on one, but not the other. I spent a lot of money on these two toilets buying, and installing them, and am happy with them but for this. My old toilets didn't have this problem, and being that they're suppose to save water this is strange.

I'd appreciate any advise on how to remedy this problem. Are there flappers that might be heavier and thereby push down and seal the tanks better. My model number is 4021N, and it's a 1.28 gpf toilet. Thanks, pith

The flapper in the still leaking tank is most likely still a problem. Just because you bought it new doesn't mean it hasn't been sitting on the store shelf for 4 years getting stiff and warped. I would take it back and get your money back on it. Cold water isn't a problem for toilet flappers, it's what they are designed for. You can either use a new Korky, or go with a replacement from Fluidmaster. [www.fluidmaster.com]