I've installed a Grohe Rapid SL 3 in 1 WC toilet frame and there is a VERY small trickle of water down the back of the pan when the flush has finished.

SOURCE: Toilet will not fill up

Some Toto fill valves have a plastic debris screen located at the inlet connection. Turn off the supply valve and remove the supply connection at the bottom of the tank. Use a mirror to inspect the screen for debris.
I agree w/ Smithbrother, the Fluidmaster fill valves are cheap and work well. The only thing they ever need is an occasional seal for $1.50 and 5 minutes to replace.

phmaddnes

• 25 Answers
• Posted on Jul 04, 2009

SOURCE: Running toilet

Mine does that also, here's what I found.; I am on a well and occasionaly sand gets caught in the valve thingy... Take the tank lid off, turn the arm that attaches to the float assy. 1/4 turn towards the back of the tank and take it out. Rinse off the gasket and pin as well as inside the hole. Reassemble and it should solve your problem.

SOURCE: toilet keeps filling tank every 10 minutes

If there is no water on the floor then the water is leaking down the main tank drain. Take off the tank lid, turn off the water supply to the toilet. Fllush as much water out as you can. Look at the main drain, sometimes if the flapper valve is connected with a chain, the chain can get caught between the flapper valve and the drain hole, the flapper valve is pliable so it tries to seal around the obstruction but can't always do it. Make sure there is obstruction, that the flapper valve is not out of shape or old and non-pliable and that it lines up with the drain hole and doesn't get "hung up" on anything.

SOURCE: New Toto toilet continues to trick water

check the water level in your tank if it is filling ,ajust the float in your tank so it stops before going over the overflow. if not your flapper is the culpret

SOURCE: villeroy & boch flush mechenism needs to be replaced

V&B US phone number is or used to be 877-505-5350 they should be able to help.