RINNAI REP199I (REU-VEP2730FFD-US)

This site calculated the 206 therms figure; the registry does not publish it. It combines the model'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. This model's UEF is 0.82. The figure holds only at that test draw, so a home using more or less hot water will burn more or less gas. The UEF comes from the DOE CCD record, retrieved 2026-09-19. This page does not give an energy figure for any other draw pattern, and none is available here. For each step behind the calculation, see how the annual cost is calculated.

The high draw pattern describes a larger household, or one where showers and laundry overlap. For that use, the model's registered maximum flow rate in gallons per minute is 4.8. The class covers 397 gas tankless units registered at the high draw pattern, and this model ranks 229th lowest among them for energy use. That puts it in the second-highest quarter of its class for energy use, 24 therms above the class median of 182 therms. If you need a lower annual figure within the same class, you can find a same-class replacement by model number. The registry data does not show how this unit performs in a smaller household, so how well it fits one is unknown.

The running cost is not stated here because it depends on the average residential gas price in your state. The page calculates it from your ZIP. At the test draw, that cost is set by the 206 therms of natural gas this unit uses each year. At the same draw, it uses 24 therms more gas a year than a unit at the class median, and the cost of that difference also depends on your rate. Enter your ZIP in the cost calculator for your own ZIP to see the figure for your area. The installed-cost range in its own block on this page is a modeled range, not a quote, and it is not repeated here.