A. O. SMITH G6-US4040NV 5**

The figure of 264 therms 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, of 0.64 with the DOE test's daily hot-water draw for the high draw pattern. It applies only to natural gas and only to that draw. The source is DOE CCD, retrieved 2026-09-19. The comparison group is the 414 models registered as a gas tank at the high draw pattern, with a median of 260 therms. This model sits 4 therms above that median. Its rank is 236th lowest energy use of 414, which places it in the second-highest quarter of its class for energy use. The steps behind the calculation are in how the annual cost is calculated.

The high draw pattern describes a larger household, or one where showers and laundry overlap. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 83 gallons for this model. The rated volume is 38 gallons. Those two figures are the ones to set against your own busiest hour. The energy figure of 264 therms fits a household that matches the high draw pattern. For a household with a different draw, this page has no value, and none is available here to estimate. If your space or fuel differs, the selector by fuel, space and size filters other units on those terms.

The running cost is not written in this text, because it depends on your state's average residential gas price. Multiply 264 therms at the high draw pattern by your own rate, or enter your ZIP in the cost calculator, which applies the state average for you. The gap to a median unit is 4 therms a year at this draw pattern, so any cost difference from the class median of 260 therms follows the same rate. The installed price range appears in its own block on this page, with its source and date, as a modeled installed-cost range and not a quote. To compare a unit of the same class, use find a same-class replacement by model number.