TAKAGI TK-310CX3 1**

The 209 therms figure does not come from the registry itself. This site calculated it from two inputs. One is the registry's UEF, the ratio of hot water delivered to energy used. The other is the DOE test's daily hot-water draw for the high draw pattern. This model's UEF is 0.81, from the DOE Compliance Certification Database (CCD), retrieved 2026-09-19. The yearly figure holds only at that test draw. The high draw pattern stands for a larger household, or one where showers and laundry overlap. The data does not give this model's energy use at any other daily draw. The page on how the annual cost is calculated sets out the method.

The site compares this model with the 397 models registered as a gas tankless unit at the high draw pattern. At the same test draw, the median model in that class uses 182 therms a year. This model uses 27 therms more than that median. With a rank of 323rd lowest, more models in its class use less energy than use more. Its maximum flow rate in gallons per minute is 4.7. The registry uses this figure to show how much hot water the unit can deliver at once. The data does not show whether that flow covers several fixtures running at once in a particular home. To compare this model with others in the same class, you can find a same-class replacement by model number.

This text does not give a running cost for the TAKAGI TK-310CX3 1**. The yearly cost of 209 therms depends on the average residential gas price in the reader's state. That price varies by state, so the page calculates the cost from the reader's ZIP instead. The same applies to the gap of 27 therms above the class median of 182 therms. That gap has no cost figure until a ZIP is entered. The cost calculator on your own ZIP turns both the model's figure and the median into a yearly cost at your local rate. The installed price range appears in its own block on this page, with its source and date. It is a modeled range, not a quote.