A fill valve with pressure chamber having an open bottom end and a diaphragm at a top end such that falling water level in the toilet tank causes the diaphragm to flex in a first direction, thereby moving a sealing member to an open position, with a venturi in the fill valve keeping the sealing member in the open position until water refilling the tank causes the diaphragm to flex in a second direction, thereby moving the sealing member back to the closed position.

A fill valve system with a float nested in a container connected to the fill valve and a siphon device passing water out of the container into the toilet tank, with the siphon device having an air vent dimensioned such that: (i) tank refilling is delayed until after the flush valve closes; (ii) the fill valve is not turned on by small leaks in the tank; and (iii) the fill valve turns off when it encounters large leaks in the tank.

A flow diverter for diverting flow between a toilet bowl and a toilet tank, the flow diverter having: a body with an inlet, outlet and pressure relief vent; and a flow adjustment mechanism rotatable around the outlet to selectively divert different percentages of flow between the outlet and the pressure relief vent by moving a stopper in and out of the outlet by rotating a sleeve of the flow adjustment mechanism around the outlet.

A flow diverter for diverting flow between a toilet bowl and a toilet tank, having: a body having an inlet, a first outlet and a second outlet; and a flow adjustment mechanism rotatable within the body to selectively divert different percentages of flow between the first outlet and the second outlet; and an air vent and diaphragm in the body to prevent a siphon flow from the first or second outlet back to the inlet.