Rheem SPEX80T

The 603 kWh figure is computed by this site, not published by the registry. It 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 very small draw pattern. This model's UEF is 0.98, as listed in DOE CCD data retrieved 2026-09-19. There are 271 models registered as an electric tankless unit at that draw pattern. This model ranks 10th lowest among them for energy use. That puts it in the lowest quarter of its class. A household that uses more or less hot water than the test day will use a different amount, and that amount is not available here. The steps are set out in how the annual energy and cost are calculated.

The very small draw pattern covers small units: a single bathroom, or a point-of-use heater under a sink. The 603 kWh figure describes this model only in that role. Its maximum flow rate in gallons per minute is 0.8, the highest flow the registry lists for it. A plumber checking a fixture can compare that fixture's flow against the 0.8 rating. A home that expects this heater to serve more than a single bathroom or sink falls outside what the very small draw pattern describes. No energy figure for a larger draw pattern is available for this model. For those cases, the selector by fuel, space and size lists other classes.

The text gives no running cost, because the cost depends on your own utility's electricity tariff. The page computes it from your ZIP, starting from the 603 kWh test-day figure. The cost calculator on your own ZIP shows the same calculation. The 12 kWh gap to the class median, noted above, also has a value that depends on your tariff, so it is not stated here. The installed price range on this page sits in its own block, with its own source and date. It is a modeled range, not a quote. To compare this unit with another in the same class, find a same-class replacement by model number.