Rheem SPEX35

The 622 kWh figure is computed by this site, not taken from the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the test's daily draw. This model's UEF is 0.95, and the source is DOE CCD data retrieved 2026-09-19. The very small pattern covers small units: a single bathroom, or a point-of-use heater under a sink. Your own yearly use will differ if your household draws more or less hot water than the federal test assumes. Because it is a test-condition number, it compares fairly only with models tested at the same draw pattern. The steps are set out on the page explaining how the annual cost is calculated.

Against the 271 electric tankless units at the very small draw pattern, this model ranks 152nd lowest in energy use. That places it in the second-highest quarter of its class for energy use, on the higher side of the median given above. Its maximum flow rate in gallons per minute is 0.4, the figure the registry lists beside its UEF. A household that needs hot water at several fixtures at once is outside the use this draw pattern describes. For that case, the selector by fuel, space and size lets you compare units at larger draw patterns. If you are matching an existing unit, you can find a same-class replacement by model number.

This page states no running cost in the text, because none can be given without your own rate. The yearly cost of 622 kWh depends on your utility's electricity tariff, which is not in the registry data. The page computes it from your ZIP, and the cost calculator on your own ZIP runs it for another ZIP. The installed price range appears in its own block with its source and date, as a modeled range rather than a quote. Not available here: this model's energy use in your home, or any figure at a draw pattern other than very small. The UEF of 0.95 and flow rate of 0.4 come from the registry; the 622 kWh figure is this site's calculation.