A flow control valve assembly is adapted for use with a water conveying device which is provided with a supply channel, a valve chamber, first and second outlet passages communicated fluidly with the valve chamber, and a mounting hole. The flow control valve assembly is mounted to the water conveying device at the mounting hole with the use of a tubular mount, and includes a piston shaft movable between a first valve position, where water from the supply channel flows through the second outlet passage, and a second valve position, where water from the supply channel flows through the first outlet passage. The flow control valve assembly further includes a temperature sensor for detecting the temperature of water in the valve chamber, and an indicator unit associated operably with the temperature sensor so as to indicate the water temperature in the valve chamber thereon.