Rheem ECO POU 6

This site computes the figure of 628 kWh from 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. The registry lists this unit with a UEF of 0.94. The source is the DOE CCD, retrieved 2026-09-19. Among the 271 electric tankless models at this draw pattern, the unit ranks 188th lowest in energy use. That places it in the second-highest quarter of its class, 13 kWh above the median of 615 kWh. The calculation is set out in the methodology for the annual figures.

The Rheem ECO POU 6 is an electric tankless unit tested at the very small draw pattern, which covers small units: a single bathroom, or a point-of-use heater under a sink. The registry lists its maximum flow rate in gallons per minute as 0.5. The figure of 628 kWh therefore suits a reader verifying a unit for that kind of small use. It does not describe use at any other draw pattern, and this page has no energy figure for one. A reader whose demand is larger than a single bathroom or a sink should not take 628 kWh as expected use. The water heater selector by fuel, space and size narrows a search, and the same-class replacement finder works from a model number.

The running cost is not written out here, because it depends on the electricity tariff the reader pays. The figure of 628 kWh is energy, not money. Multiplying it by the reader's own rate per kilowatt-hour gives the yearly cost, and that rate differs by utility. The cost calculator for your own ZIP does this multiplication. Because the unit sits 13 kWh above the class median of 615 kWh, a unit at the median would cost less per year at the same rate, by 13 kWh multiplied by that rate. The modeled installed-cost range appears in its own block on this page, with its source and date, and is not a quote. Its figures are not repeated here.