Noritz introduces the NR501 outdoor tankless water heater for one-bath homes. It has an Energy Factor of 0.86 for natural gas and 0.85 for liquid propane. The NR501 has a 12-year heat exchanger, scale-detection software and a compact design with an integral readout window. Part of the ValueSolutions series of gas-fired residential tankless water heaters, the NR501 carries the following specifications: an input range of 15,000 to 120,000 Btuh, a flow rate of 0.5 to 5 gal. per min. and a 1/2” gas-line connection. It is equipped with the fully modulating, low-NOx Eco-Burner.