The NCC1991 condensing tankless water heater from Noritz America delivers a thermal efficiency of 94%, with an input range of 16,000 to 199,900 Btu. This enables the unit to meet the hot water needs of larger residential applications as well as a wide variety of commercial projects. Two NCC199-DV units can be coupled using a Quick Connect cable to provide an input of nearly 400,000 Btu, with a turndown ratio of more than 36:1.