NAVIEN NPE-240A2

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 draw pattern. The registry lists this model at a UEF of 0.95, retrieved from DOE CCD on 2026-09-19. At that test draw, the model ranks 45th lowest in energy use among the 397 models in its class. The figure covers the test's daily draw only. How much gas a home uses at its own daily draw is not available here. The steps behind the number are set out on the page about how the annual energy and cost figures are calculated.

The high draw pattern represents a larger household, or a home where showers and laundry overlap. The 178 therms figure applies most directly to that kind of use. The registry also lists a maximum flow rate in gallons per minute of 5.6 for this unit. That rate is the most hot water it delivers at once, so compare it with the fixtures a home runs at the same time. A smaller household with lower daily use falls outside the condition behind 178 therms. This data does not include its yearly gas use, and the 45th ranking does not apply to it. To compare units by other sizes or fuels, use the water heater selector by fuel, space and size.

This text does not state the running cost. It depends on the average residential gas price in the reader's state, so the page computes it from the reader's ZIP. The same applies to the 4 therms gap between this model and the 182 therms class median. What that gap is worth each year depends on the local gas rate, and no figure is given here. To see the cost at your own rate, open the water heater cost calculator for your ZIP. The installed price range appears in its own block on this page, with its source and date. It is a modeled range, not a quote.