Rheem SPEX55

This site calculated the 615 kWh figure; the registry does not list it. The calculation uses the registry's UEF, the ratio of hot water delivered to energy used, and the DOE test's daily hot-water draw for the very small draw pattern. For this model the UEF is 0.96, from DOE CCD data retrieved 2026-09-19. The result holds only at that test draw. It does not describe use at other daily draws. The data here does not show how far a real household's daily draw differs from the test's. The steps behind the figure are set out in how the annual cost is calculated.

The very small draw pattern covers small units, such as a heater for a single bathroom or a point-of-use heater under a sink. The registry lists this model's maximum flow rate in gallons per minute as 0.6. The data here gives no figure for supplying several fixtures at the same time, so that is not known from this page. A reader sizing a heater for a whole house is outside the case the 615 kWh figure describes. The same applies to anyone whose daily hot-water use is larger than the very small pattern. To compare other units, use the water heater selector by fuel, space and size. To match this unit's class, you can find a same-class replacement by model number.

The class for comparison is the 271 models registered as an electric tankless unit at the very small draw pattern. The summary above gives this model's position against the class median. In the ordered list of 271 models, it ranks 77th lowest in energy use. This text does not state a running cost. The cost depends on your own utility's electricity tariff, so the page works it out from your ZIP instead of estimating it. You can get that figure for the 615 kWh of yearly use from the cost calculator for your own ZIP. The installed price range has its own block, with its source and date. It is a modeled range, not a quote.