... , 20KW, 24KW, 32KW, 40KW. Rated hot water output: 5 L/min, 6 L/min, 7 L/min, 8 L/min ... G1/2" Advantages: Two power systems for choice Water-gas linked automatic control, easy operation; Model of Ignition ... . Water over high pressure protection device; Over freezing protection device; Super low water pressure starting design Gas Water Heater, Instant Tankless Water Heater, Natural Gas Water Heater