STATE T-H3J-OS-N 1**

The 178 therms figure is calculated by this site. It is not a value published by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the high draw pattern. This model's UEF is 0.95. The UEF was retrieved from the DOE Compliance Certification Database on 2026-09-19. The result therefore describes gas use on the test day's draw, not in a specific home. A household that uses more or less hot water than that test day will use a different amount of gas. The method behind the annual energy and cost figures sets out each input and step.

The 45th ranking compares this model with the 397 models registered as a gas tankless unit at the high draw pattern. The 4 therms gap from the class median holds only at the test's daily draw. The figure applies best to a household close to that pattern: a larger household, or one where showers and laundry overlap. The listed maximum flow rate in gallons per minute is 4.7. A home that needs more than 4.7 gallons per minute at once would exceed this listing. Energy use at other draw patterns is not available in this data. To check other units, use the water heater selector by fuel, space and size or the same-class replacement search by model number.

The running cost is not given in this text. It depends on your state's average residential natural gas price, applied to 178 therms a year at the high draw pattern. The page calculates that cost from your ZIP code, so the result matches your own rate. You can also enter a different ZIP in the cost calculator for your own ZIP. The 4 therms gap from the class median becomes a cost difference in the same way: the gap in therms multiplied by your gas price. The installed price range appears in its own block, with its source and date. It is a modeled range of installed costs, not a quote from an installer.