I have a ONE-PIECE Cadet 3. The water lever lowers enough the make the system to refill the tank. It was installed 11 months ago. I have NOT tried any thing to fix the problem yet.

John

Sounds like a leaking flush valve (flapper).

Yep I agree with Hkstroud it can be the flapper valve or flush valve, Thanks.

John

Lift the lid and run your fingers around the flapper. Any nicks, rough spots or wavey edges and the flapper must be replaced. You should have a quarter play in the linkage and the tank level should be set at 1/2" below the white overflow tube. Good luck, Tom