NAVIEN NHW700-160SU-NG

The figure of 209 therms is not a registry entry. This site computed it from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.81 for this model, and from the DOE test's daily hot-water draw for the high draw pattern. The source is DOE CCD, retrieved 2026-09-19. Among the 397 models registered as a gas tankless unit at the high draw pattern, this one ranks 323rd lowest in energy use. That places it in the highest quarter of its class for energy use, 27 therms above the class median of 182 therms. The method for the annual calculation is documented separately.

The high draw pattern describes a larger household, or one where showers and laundry overlap, so the 209 therms figure is most relevant to a home that matches that description. The registry lists a maximum flow rate in gallons per minute of 4.1 for this model. Because the unit sits 27 therms above the class median of 182 therms, it is a weaker match for a reader whose priority is low gas use within its class, where it holds a rank of 323rd lowest of 397. That reader can look for a same-class replacement by model number and compare ranks. What a specific household would use at another draw pattern is not available in the registry data.

The running cost is not stated in the text because it depends on the state average residential gas price, which differs between readers. Multiply 209 therms by the gas price for the reader's state, or enter a ZIP in the cost calculator to have it done. The result holds only for the high draw pattern at the federal test's daily draw. A household that draws more or less hot water will differ, and that difference is unknown from this data. The modeled installed-cost range appears in its own block on the page, with its source and date. To compare units by fuel, space and size, use the water heater selector.