AMERICAN TK-110U-I 2**

The figure of 137 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 medium draw pattern. That pattern stands for a typical household on a busy morning. The source is the DOE CCD, retrieved 2026-09-19. The unit ranks 52nd lowest energy use of 80, which places it in the quarter just below the highest-energy quarter of its class. Its distance from the class median of 135 therms is 2 therms. The data used here gives no spread for the class beyond the median, so no wider comparison is made.

The figure fits a household whose hot-water use resembles the medium draw pattern. The registry lists a maximum flow rate in gallons per minute of 3.5 for this unit. That is a rated maximum, and this page does not determine whether it covers a given number of fixtures running together. The figure fits less well where use is clearly heavier or lighter than the test's daily draw, because energy use at other draw patterns is not available here. Because the unit sits above the median of 135 therms, a reader who wants a lower figure can look for a same-class replacement by model number or narrow the field with the water heater selector.

No running cost is written in this text because it depends on your state's average residential gas price, which is not in the data. The cost calculator for your own ZIP applies that price to 137 therms and returns the annual cost. The steps behind that calculation are described in how the annual cost is calculated. The 2 therms gap to the class median of 135 therms converts to a cost only at your own rate, so no cost gap is stated here. The modeled installed-cost range appears in its own block with its source and date. It is a modeled range, not a quote, and it is not repeated in this text.