A. O. SMITH T-H3M-DV-N 1**

The figure of 123 therms is this site's own calculation, not a registry entry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.9 with the daily hot-water draw that the DOE test assigns to the medium draw pattern. The result is natural gas use at that draw only. It comes from the DOE CCD, retrieved 2026-09-19. The medium pattern describes a typical household on a busy morning. A home that draws more or less hot water than the test assumes will use a different amount. This page has no figure for other draw patterns, so that value is not available here.

Against the 80 models registered as a gas tankless unit at the medium draw pattern, this unit sits 12 therms below the class median of 135 therms. Its rank is 10th lowest of 80, which places it in the lowest quarter of its class for energy use. That suits a household whose use resembles the medium pattern, and a reader checking a gas figure against peers, for example when comparing a same-class replacement found by model number. It does not show whether the unit fits a different draw pattern. The maximum flow rate in gallons per minute is 3.3. The data here does not show how that limit compares with a specific home's simultaneous use. The selector by fuel, space and size covers those questions.

Running cost is not stated in this text because it depends on the state average residential gas price, which differs by reader. The 123 therms figure at the medium draw pattern is the input. Multiplying it by your own gas price per therm gives the yearly cost. The cost calculator does this from your ZIP, and how the annual cost is calculated sets out the method. The modeled installed-cost range for A. O. SMITH T-H3M-DV-N 1** appears in its own block with its source and date. It is a modeled range, not a quote, and it is not restated here. No cost value on this page has been estimated.