Lennox WHGS040T40NANE****

The 185 therms figure is computed by this site, not published by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, which is 0.6 for this model, with the daily hot-water draw that DOE's test assigns to the medium draw pattern. The result is for natural gas only and holds only at that test draw. A household that draws more or less hot water than the test will use a different amount. The source is the DOE CCD, retrieved 2026-09-19. The steps behind the calculation are set out in the methodology for the annual cost.

In its class of 288 models registered as a gas tank at the medium draw pattern, this model ranks 89th lowest for energy use. That places it in the second-lowest quarter of the class, and its 185 therms is 0 therms from the class median of 185 therms. The medium draw pattern describes a typical household on a busy morning, so the figure suits homes whose use is close to that. The model has a first hour rating, the gallons of hot water available in the first hour from a full tank, of 73 gallons and a rated volume of 38 gallons. This page has no data on any household's peak demand, so whether those gallons cover a given home cannot be judged here. The water heater selector by fuel, space and size can narrow the options.

The running cost is not written here because it depends on your state's average residential gas price, and that price is not part of this page's data. Applying a price per therm to the 185 therms would give an annual gas cost only at the medium draw pattern. A different rate or different hot-water use changes the result. The cost calculator on your own ZIP applies your state's rate to this model. The installed-price range appears in its own block with its source and date. It is a modeled range, not a quote, and it is not repeated in this text. For a unit in the same class, you can find a same-class replacement by model number.