Lennox WHGS050T40*PXS****

This site calculated the 242 therms figure; the registry does not list 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. For this model the UEF is 0.7, from DOE CCD data retrieved 2026-09-19. Among the 414 gas tank models at the high draw pattern, it ranks 90th lowest in energy use. That places it in the lowest quarter of its class for energy use. The figure applies at the test's daily draw only. Energy use at other draws is not available in this data. The steps behind the number are set out in how the annual cost is calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. This model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 81 gallons. Its rated volume is 48 gallons. Those two values describe the demand level it was rated against. A home with lighter daily use falls outside the condition behind the 242 therms figure. For that home, the figure does not describe expected use, and no lighter-draw figure is available here. To compare units by fuel, space and size, use the water heater selector. For a like-for-like check, the same-class replacement search by model number finds units registered in the same class.

The running cost is not given in this text. It depends on your state's average residential natural gas price, so the page computes it from your ZIP. At any rate, the cost follows the 242 therms of gas per year at the high draw pattern. The 18 therms gap to the 260 therms class median carries the same condition. It is a gap at the test's draw, and its cost depends on your own rate. The cost calculator for your own ZIP applies that rate to this model. The installed-cost range appears in its own block, with its source and date. It is a modeled range, not a quote.