AMERICAN TK-310U-I 2**

The figure of 209 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 0.81 with the DOE test's daily hot-water draw for the high draw pattern. The registry data was retrieved from DOE CCD on 2026-09-19. The condition matters: the number describes the federal test's draw, not a particular household's use, so real consumption can differ. Among the 397 models registered as a gas tankless unit at this draw pattern, AMERICAN TK-310U-I 2** ranks 323rd lowest in energy use among them. That places it in the highest quarter of its class for energy use, 27 therms above the class median of 182 therms.

The high draw pattern describes a larger household, or one where showers and laundry overlap. If that matches your home, 209 therms is the figure to compare, because it belongs to that draw. For a household that wants the lowest gas use at this draw pattern, the position matters: the models ranked ahead of 323rd use less, and the distance from the median is 27 therms. The registry lists a maximum flow rate in gallons per minute of 4.7. It does not state how many fixtures that flow serves at once, so this page makes no claim about simultaneous use. To compare within the same class, use the same-class replacement lookup by model number or the selector by fuel, space and size.

The text gives no running cost because it depends on the state average residential gas price, which differs by reader. This page computes it from your ZIP instead of estimating one. In principle it is 209 therms multiplied by that price per therm, and the 27 therms gap from the class median of 182 therms is priced at the same rate. Try the cost calculator on your own ZIP, and read how the annual cost is calculated for the inputs. The modeled installed-cost range appears in its own block with its source and date; it is a modeled range, not a quote. Measured household consumption for this model is not available in the registry data.