TAKAGI T-H3S-DV-N 1**

The registry does not print the 178 therms figure. This site calculated it from the registry's UEF, the ratio of hot water delivered to energy used, and from the daily hot-water draw in the DOE test for the high draw pattern. The registered UEF for this model is 0.95. The high pattern describes a larger household, or one where showers and laundry overlap. The registry data comes from the DOE CCD, retrieved 2026-09-19. If your figure is different, first check whether it uses another draw pattern. The annual value only applies at the daily draw used in the federal test. The steps are explained in how the annual cost is calculated.

Within its class, the T-H3S-DV-N 1** ranks 45th lowest energy use of 397 models registered as a gas tankless unit at the high draw pattern. That puts it in the lowest quarter of its class for energy use. Its 178 therms is 4 therms below the class median of 182 therms. The registry also lists a maximum flow rate in gallons per minute of 5.4 for this unit. You can compare that rate with the combined flow of the fixtures a home uses together. The class comparison only covers the high draw pattern. Annual use for a home that uses less hot water is not available here. To compare other models in this class, use find a same-class replacement by model number.

No running cost is given in this text, because it depends on your state's average residential gas price. The page calculates it from your ZIP and the 178 therms of natural gas at the high draw pattern. If a seller quotes a yearly running cost for this model, it can only be checked if they also give the rate they used. Enter your ZIP in the cost calculator for your own ZIP to see the cost at your rate. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote. The registry has no energy use figure for homes whose hot-water demand differs from the test draw.