Pressure from the input water line (26) holds a toilet's flush-valve member (12) in its seat so as to prevent water in the toilet tank (16) from flowing through flush ports (18) and a flush conduit (22) into the toilet bowl or urinal. To release water through the flush conduit (22) a solenoid (42) is actuated to relieve the pressure acting on the flush-valve (12) so that a bias spring (24) lifts the flush-valve (12) off its seat (14). A solenoid (118) for performing this function can be located remotely from the flush-valve assembly and communicate with it by a hydraulic line (108).