AMERICAN GPDL-40 3**

The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.68 for this model. This site combines that UEF with the federal test's daily hot-water draw for the medium pattern to reach 163 therms of natural gas a year. The registry does not publish that annual figure itself. The source is DOE CCD, retrieved 2026-09-19. Against the class median of 185 therms, the model sits 22 therms lower. That gives it the 5th lowest energy use of 288 and places it in the lowest quarter of its class. The comparison covers only models registered as a gas tank at the medium draw pattern.

The figure suits a household whose hot-water use resembles the medium pattern, a typical household with a busy morning peak. The model has a first hour rating, the gallons of hot water available in the first hour from a full tank, of 74 gallons and a rated volume of 38 gallons. A household that draws more hot water than the test assumes would be expected to use more than 163 therms. The data here does not say by how much. The figure describes the test condition, not any particular home. To compare by fuel, space and size, use the water heater selector, or find a same-class replacement by model number.

The running cost is not stated in the text because it depends on the state average residential gas price, which differs by location. The cost calculator on your own ZIP applies that price to the 163 therms shown above. The methodology page explains how the annual cost is calculated. The same price applies to the class median of 185 therms, so the gap of 22 therms in energy use carries through to cost in the same proportion. The installed price range is shown in its own block as a modeled range, not a quote.