The Noritz Residential Combination Boiler (NRCB) allows for simultaneous residential domestic hot water and space heating and performs at 95 percent annual fuel utilization efficiency. Unlike traditional combination boiling systems, which can provide only space heating or hot water at any given time, the NRCB’s simultaneous capabilities are easy to control and beneficial for applications that do not store or deliver heat energy efficiently. It is available in two models: the NRCB180DV has a maximum gas input Btu/h of 180,000 for hot water and 100,000 Btu/h for space heating. Its maximum flow rate is 9.8 gpm; and the NRCB199DV has a maximum gas input Btu/h of 199,000 for hot water and 120,000 Btu/h for space heating. Its maximum flow rate is 11.1 gpm. 714-433-2905; www.noritz.com.