GSW WATER HEATERS GPVL-40 2**

It holds 38 gallons in the test, 2 gallons less than its 40-gallon sold size. Over one hour from a full tank, it gave 73 gallons in the test (its first-hour rating). That is 35 gallons more than its tank holds, since it reheats during the hour. In the first hour, 477 of the 763 gas storage models give more hot water. The median gas storage model gives 78 gallons in its first hour.

It was not listed as ENERGY STAR certified on Oct 26, 2026. In tests, 67% of the energy went to hot water, so its UEF is 0.67. Its test simulated a day of medium hot water use (its draw pattern). Of 288 gas storage models with the same draw pattern, 19 have a higher UEF. For its type and draw pattern, the median UEF is 0.60. Of the energy spent to reheat water, 79% goes into it (its recovery efficiency).

It is sold as G640S40N-PV-ES2 2**, G640S40P-PV-ES2 2*1, and G840S40N-PV-ES2 2**. Its test figures match those of 6 other basic models. Each of the 6 other brands lists one of them. You can find the whole group on the page for the A. O. Smith GPVL-40 2**.

In 2 states, 2 rebate programs may accept it.