NAVIEN NPE-210A2

This site computed the 178 therms figure; the registry does not publish it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the high pattern. Under the federal test, this model's UEF is 0.95. The annual figure holds only at that test draw. A home that draws more or less hot water each day will use a different amount of gas. The registry data comes from DOE CCD, retrieved 2026-09-19. Among the 397 gas tankless models registered at the high pattern, this one ranks 45th lowest for energy use. Our page on how the annual cost is calculated lists each step.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. That is the daily use behind the 178 therms figure, so the figure applies most directly to a home like that. The registry lists this unit's maximum flow rate in gallons per minute as 5. The figure fits less well for a smaller household, whose daily draw may sit below the test's assumption. This page has no energy figure for this model at another draw pattern. It also covers natural gas only; a propane figure is not available here. To compare other units, use the selector by fuel, space and size. To match a unit already installed, use the same-class replacement search by model number.

This text does not state the running cost. It depends on your state's average residential gas price, so the page works it out from your ZIP. The calculation applies that rate to the 178 therms used at the high pattern. The 4 therms gap to the class median, noted above, becomes a cost difference only at your rate. That cost difference cannot be shown until a rate is applied. Use the cost calculator on your own ZIP to see it. The installed price appears in its own block with its source and date. That block shows a modeled installed-cost range, not a quote, and this text does not repeat its figures.