Rinnai expands its commercial tankless water heater line with the introduction of the C199 model. The new unit is a condensing tankless water heater with a heat exchanger designed specifically for the demands of business. These 199,000 Btu models save on operation and life-cycle costs. The C199 is available in both natural gas and propane, is Commercial EnergyStar-certified and is capable of temperatures between 98° and 185° F without the use of an additional controller.