Lennox WHGS040T40NAXS****

The 185 therms figure is computed by this site, not taken from the registry. It combines the model's UEF, the ratio of hot water delivered to energy used, which is 0.6. It also uses the DOE test's daily hot-water draw for the medium draw pattern. The UEF comes from the DOE CCD, retrieved 2026-09-19. Among the 288 models registered as a gas tank at the medium draw pattern, this one ranks 89th lowest for energy use. Its figure matches the class median, a difference of 0 therms. A plumber or seller checking a label can treat the UEF and the class rank as the registry-backed values. The steps behind the annual figure are set out in how this site calculates annual energy and cost.

The medium draw pattern stands for a typical mid-sized household on a busy morning. This model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 74 gallons. Its rated volume is 38 gallons. The 185 therms figure applies to homes whose daily use resembles the medium test draw. A home that draws more or less hot water than the test assumes falls outside that figure. Its actual gas use is not available in the registry data, and this page does not estimate it. To compare this unit with other gas tanks registered at the same draw pattern, use the same-class replacement search by model number.

The text gives no running cost, because the cost of 185 therms of natural gas depends on your state's average residential gas price. The page computes that cost from your ZIP in its own block. The cost calculator for your own ZIP applies the same annual figure to your rate. Because this model's energy use equals the class median of 185 therms, its running cost on any given rate equals that of a median unit in its class. The installed price range sits in a separate block with its source and date. It is a modeled installed-cost range, not a quote, and this text does not restate it.