Stiebel Eltron Mini-E 3.5-1

This site computed 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. It combines that UEF with the daily hot-water draw that the DOE test sets for the very small draw pattern. For this model, the UEF is 0.96. The figure applies only at that test draw. A home that uses more or less hot water will use a different amount of energy. The source is DOE CCD, retrieved 2026-09-19. Among the 271 models registered as an electric tankless unit at this draw pattern, this model ranks 77th lowest for energy use. That puts it in the second-lowest quarter of its class. The steps are set out in how the annual cost is calculated.

The very small draw pattern covers small units: 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 0.4. That is the highest flow the registry records for this unit. A plumber verifying a sink or basin setup can compare 0.4 with the flow of the fixture it will serve. A home that needs hot water at several fixtures at once is outside the draw pattern this model was tested against. For that home, the 615 kWh figure does not describe expected use. The selector by fuel, space and size filters models by those conditions.

The text on this page gives no running cost. The cost of 615 kWh of electricity depends on the reader's own utility electricity tariff. The page computes that cost from the reader's ZIP, and the cost calculator on your own ZIP runs the same calculation. This model sits 0 kWh from the class median of 615 kWh. On any given rate, its computed cost therefore matches a median-use model in this class at the same test draw. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote. The registry does not show what this model will cost to run under a specific home's own hot-water use.