Rheem XE40T10HS45U1

It holds 36 gallons in the test, 4 gallons less than its 40-gallon sold size. Over one hour from a full tank, it gave 60 gallons in the test (its first-hour rating). That is 24 gallons more than its tank holds, since it reheats during the hour. In the first hour, 371 of the 481 heat pump models give more hot water. The median heat pump model gives 72 gallons in its first hour.

The single model number sold under it is ENERGY STAR certified. In the test, it gives 3.83 units of hot water energy per unit it uses (its UEF). A UEF above 1 is possible because it moves heat from the air into the water. In the test, daily hot water use was set to medium (its draw pattern). Among 226 heat pump models on its draw pattern, 23 have a higher UEF. On its draw pattern, the median heat pump UEF is 3.68. While it reheats, the water gains 434% of the energy it uses (its recovery efficiency).

Its test figures match those of 28 other basic models. Those basic models are sold with Friedrich, Richmond, and Ruud as their brand names. For the full group, see the Rheem PROPH40 T2 RH375-SO page.

In 20 states, 21 rebate programs may accept it. Another 7 rebate programs may accept it if it meets their other terms.