ECOSENSE RHE40S

It holds 37 gallons in the test, 3 gallons less than its 40-gallon sold size. It delivers 87 gallons of hot water in the test's first hour. That is 50 gallons more than its tank holds, since it reheats during the hour. Of 763 gas storage models, 143 give more hot water in the first hour. The median gas storage model gives 78 gallons in its first hour.

On Oct 26, 2026, this heater was not listed as ENERGY STAR certified. In tests, 83% of the energy it uses ends up as hot water (UEF 0.83). In the test, daily hot water use was set to high (its draw pattern). Of 434 gas storage models with the same draw pattern, 46 have a higher UEF and 384 a lower one. On its draw pattern, the median gas storage UEF is 0.66. Of the energy spent to reheat water, 92% goes into it (its recovery efficiency).

Its test figures match those of 3 other basic models. Those basic models are sold with Rheem, Richmond, and Ruud as their brand names. For the full group, see the Rheem RHE40S.

It may qualify for 2 rebate programs.