TAKAGI TK-310C-NI 1**

This site computed the 209 therms figure; the registry does not publish it. 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. For this model the UEF is 0.81. The source is the DOE Compliance Certification Database, retrieved 2026-09-19. The figure holds only at that test draw. A household that draws more or less hot water will use a different amount of gas. The class is the 397 models registered as a gas tankless unit at the high draw pattern. Ordered from lowest energy use, this unit ranks 323rd of 397. That places it in the highest quarter of its class for energy use. See how the annual energy and cost figures are calculated for each step.

The high draw pattern stands for a larger household, or one where showers and laundry overlap. The 209 therms figure describes that kind of use. For this model, the registry lists a maximum flow rate in gallons per minute of 4.6. That flow limits how much hot water the unit delivers at one time. It matters when showers and laundry run together. The data does not state the temperature rise at which that flow holds, so that condition is not available here. The page's figures apply directly to a household that matches the high draw pattern. That household should also expect gas use 27 therms above the class median at the test draw.

For a smaller household, the high draw pattern figure does not describe its use. This data has no figure for this model at a lower draw pattern. Within its class, a model closer to the 182 therms median would use less gas at the same test draw. To compare, find a same-class replacement by model number. This text does not state the running cost. It depends on your state's average residential gas price, so the page calculates it from your ZIP. Use the cost calculator for your own ZIP to apply your rate to 209 therms. The installed price range has its own block, with its source and date. It is a modeled range, not a quote.