Rheem SPEX1812T

The figure of 615 kWh is computed by this site, not published by the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.96 for this model. It then applies that UEF to the DOE test's daily hot-water draw for the very small draw pattern. The source is the DOE CCD, retrieved 2026-09-19. The figure holds only at that test draw, so a home that uses more or less hot water than the test assumes will use a different amount of electricity. The registry also lists a maximum flow rate in gallons per minute of 0.2 for SPEX1812T. The calculation steps are set out in how the annual cost is calculated.

Among the 271 models registered as an electric tankless unit at the very small draw pattern, this unit ranks 77th lowest in energy use. That places it in the second-lowest quarter of its class. Its 615 kWh equals the class median of 615 kWh, a difference of 0 kWh, so on energy use alone it sits at the middle of the class, not above or below it. The figure suits a reader checking a unit meant for small loads, such as a single bathroom or a point-of-use heater under a sink. It does not describe larger households or other draw patterns, and this page has no data for them. To compare against other units in the same class, use find a same-class replacement by model number.

The running cost is not stated here because it depends on your own utility electricity tariff. Multiply 615 kWh by your rate per kilowatt-hour to get a yearly figure for SPEX1812T at the test draw. The cost calculator on your own ZIP does this with the tariff for your location. Actual hot-water use in your home is not in the registry, so real consumption may differ from 615 kWh, and this page cannot say by how much. The modeled installed-cost range appears in its own block on the page, with its source and date, and is not repeated in this text.