JOHN WOOD ATHR-160M 1**

This site computed the 178 therms figure; the registry does not publish it. The calculation 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. This model's UEF is 0.95, from the DOE CCD, retrieved 2026-09-19. Among the 397 gas tankless models at the high draw pattern, it ranks 45th lowest in energy use. That puts it in the lowest quarter of its class for energy use. The figure applies only at the test's daily draw. It does not describe a home whose daily hot-water use differs from that pattern. The steps behind it are set out in how the annual energy and cost are calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. The 178 therms figure and the 45th rank describe use of that kind. The registry lists this model's maximum flow rate in gallons per minute as 4.8. A home that needs more than 4.8 gallons per minute at once is above that listed maximum. For a smaller household with lighter daily use, energy use at a lower draw pattern is not available in this data. The rank also cannot be applied to units tested at another pattern. To compare other fuels or sizes, use the water heater selector by fuel, space and size. To find another model in this class, use the same-class replacement search by model number.

The running cost is not written here, because it depends on your state's average residential natural gas price. The page computes it from your ZIP by applying that price to the 178 therms used at the high draw pattern. To see it, enter your ZIP in the cost calculator for your own ZIP. The 4 therms gap to the class median has no fixed cost value either; that value depends on the same rate. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote, and this text does not restate its figures. This commentary does not estimate the running cost or the installed range.