STATE ATI-199B-N 1**

This site calculated the 206 therms figure; the registry does not list it. The calculation uses the model's UEF, the ratio of hot water delivered to energy used, and the daily hot-water draw in the DOE test for the high pattern. The registry lists a UEF of 0.82 for this model in DOE CCD data retrieved 2026-09-19. The figure describes the federal test's daily usage, not a particular home. A household that uses more hot water than the test will burn more gas than 206 therms. One that uses less will burn less. The steps of the calculation are set out in how the annual energy and cost figures are calculated.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. The registry lists this unit's maximum flow rate in gallons per minute as 5.2. Among the 397 gas tankless units tested at this pattern, it ranks 229th lowest for energy use. That puts it in the second-highest quarter of its class. The models ranked ahead of it use less gas under the same test. A figure for this unit at a lower draw pattern is not available in this data. If you are checking a unit against others in the same class, try the same-class replacement search by model number.

The text does not give a running cost for this model. The cost of 206 therms of natural gas depends on your state's average residential gas price. The page uses your ZIP to find that price. The running cost calculator for your own ZIP applies your state's price to this model's annual figure. The 24 therms gap to the class median works the same way. It is the extra gas this unit uses compared with the median model at the test draw, whatever your gas price. The installed-cost range shown in its own block is a modeled range with a source and date, not a quote.