Lennox WHGS050T40PAXS****

The 260 therms figure is computed by this site and is not taken from the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.65 for this model. That ratio is then applied to the DOE test's daily hot-water draw for the high draw pattern. The UEF comes from the DOE Compliance Certification Database, retrieved 2026-09-19. The result holds only at that test draw, so a home using more or less hot water will burn a different amount of gas. How large that difference would be is not available from the registry. The steps 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. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 86. Its rated volume is 47 gallons. On energy use it ranks 204th lowest of the 414 gas tank models at the high draw pattern. That places it in the second-lowest quarter of its class, level with the class median of 260 therms. To compare it with other registered units, use the water heater selector by fuel, space and size.

A home that draws less hot water than the high pattern is not described by the 260 therms figure. This page has no figure for this model at other draw patterns. The running cost is not stated in this text, because it depends on your state's average residential gas price. The page computes it from your ZIP, using the 260 therms a year at the high draw pattern. You can run the same figure on another ZIP in the cost calculator on your own ZIP. If you need a unit in the same class to swap for this one, find a same-class replacement by model number. The modeled installed-cost range appears in its own block, with its source and date.