PFFW-SXX-001 Navien NaviCirc Recirculation Valve Only for use with NPE-A Series Tankless Water Heaters NaviCirc is a simple plumbing device that uses the existing hot and cold water lines to reduce the wait time for hot water at the faucet without the need for a dedicated recirculation return lineDesigned and optimized for use with Navien NPE-A Series water heater modelsAutomatically blocks circulation when the hot water temperature within the valve is about 95°F (35°C)Compatible with the Navien HotButton Kit for demand-type recirculation systems Specifications :Valve Only Part Number: PFFW-SXX-001Water Flow Rate Range: 0.53 - 1.06 GPM (2.0 - 4.0 LPM)Crossover Shutoff Temperature: 95˚F (35˚C)Water Temperature Range: 41˚F to 180˚F (5˚C to 82˚C)Ambient Temperature Range: 32 - 122˚F (0 - 50˚C) (Indoor use only)Storage Temperature Range: 23 - 122˚F (-10 - 50˚C)Maximum Water Pressure: 150 psiConnection Size: 1/2” NPSInstallation Operation: Horizontal OnlyDimensions (in): 5.62 x 3.93 x 2.19Weight (lb): 1.1 lb (0.5 kg)Warranty: 3 Years