Upgrade your building’s operations. The Hubbell Prime NX Plus is high-efficiency condensing gas water heater ideal for retrofits. It operates at up to 99.9% efficiency with inputs from 1250 to 4000 MBTU. Includes an ASME H stamped stainless steel heat exchanger and an optimized burner. Ultra-low NOx emissions. Fully integrated digital control system for monitoring critical operating parameters. Compact design and packaged in an outdoor-rated enclosure.