RINNAI RE199I (REU-VE2737FFD-US)

This site computed the 206 therms figure; the registry does not state it. The calculation 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 pattern. For this model the UEF is 0.82. The registry data came from the DOE CCD and was retrieved on 2026-09-19. The figure therefore holds only at the federal test's daily draw. A household that draws more or less hot water than that test will use a different amount of gas. The registry does not show how far your own use differs from the test. The page on how the annual energy and cost figures are calculated sets out each step.

The class is the 397 models registered as a gas tankless unit at the high draw pattern. Within it, this model ranks 229th lowest energy use of 397. That places it in the second-highest quarter of its class for energy use. The high pattern describes a larger household, or one where showers and laundry overlap. For that kind of household, the 206 therms figure applies as tested. The registry also lists a maximum flow rate in gallons per minute of 4.6 for this unit. Models ranked ahead of it at the same pattern use less energy than 206 therms a year. To compare it with units in the same class, use the tool to find a same-class replacement by model number.

This text does not state a running cost. The cost depends on your state's average residential gas price, so the page computes it from your ZIP. Enter it in the water heater cost calculator for your own ZIP to price the 206 therms at your rate. The 24 therms gap to the class median depends on your state's rate in the same way. An installed-cost range appears in its own block on this page, with its source and date. That range is a modeled installed cost, not a quote. Neither the running cost nor that range covers gas used beyond the federal test's daily draw. The registry does not provide those amounts.