With more power than any tankless water heater in its class, the NR981 series is ideal for mid-size homes with up to 4 showers. Built-in features include safety lock-out, freeze protection, and high elevation adjustment. PVC CANNOT be used for venting. Features: Standard Input - gas consumption ranges from 16,000 BTUh to 199,900 BTUh Capacity Range - flow rates from 0.5 GPM up to 9.8 GPM Heat Exchanger - manufactured with commercial grade copper, 25% thicker piping than standard models Durable steel casing with polyester coating Specifications: Width: 13-13/16" Height: 23-5/8" Depth: 9-3/8" Product Weight: 47 Fuel Type: Gas Gas Type: Natural Gas Gas Connection: 3/4" Water Connection: 3/4" Water Pressure (Min): 15 psi Water Pressure (Max): 150 psi Temperature (Min): 100° F Temperature (Max): 140° F Voltage: 120V Frequency: 60 Amperage: 1.208