AMERICAN STANDARD WATER HEATERS GN40T2-3-*

The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.6 for the AMERICAN STANDARD WATER HEATERS GN40T2-3-*. The registry does not state annual energy use for this model. This site computed 185 therms of natural gas per year from that UEF and the DOE test's daily hot-water draw for the medium draw pattern. The figure comes from DOE CCD data retrieved 2026-09-19. The class median for the 288 models registered as a gas tank at the medium draw pattern is 185 therms. This model differs from that median by 0 therms. Its energy use ranks 89th lowest of 288, which places it in the second-lowest quarter of its class.

The energy figure of 185 therms applies only to the medium draw pattern. It suits a reader checking a household whose hot-water use is close to that pattern, because the figure was calculated at that draw. It does not describe a household with much heavier or lighter use, and energy use at other draws is not available on this page. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 73 gallons for this model, and the rated volume is 38 gallons. To compare options by fuel, space and size, use the water heater selector. To look for a same-class replacement, enter GN40T2-3-* in the replacement finder.

Running cost is not stated in the text because it depends on your state's average residential gas price. The cost is 185 therms multiplied by that price, so a different rate changes the result while the 0 therms gap to the class median of 185 therms stays the same. The cost calculator computes it from your ZIP code. The methodology page explains how the annual cost is calculated. Installed cost is shown in its own block on the page as a modeled range, not a quote. The annual figure reflects the federal test's draw, not measured use in your home, and actual use may differ.