Ariston PV40SLN*

It holds 39 gallons in the test, 1 gallon less than its 40-gallon sold size. It delivers 71 gallons of hot water in the test's first hour. Reheating lets it give 32 gallons beyond the 39 gallons in its tank. Among 763 gas storage models, 493 have a higher first-hour rating. The median gas storage model gives 78 gallons in the first hour of the test.

As of Oct 26, 2026, it was not listed as ENERGY STAR certified. In the test, 36% of its energy does not reach the hot water (UEF 0.64). Its test ran at the medium level of daily hot water use. Of 288 gas storage models with the same draw pattern, 43 have a higher UEF and 227 a lower one. For its type and draw pattern, the median UEF is 0.60. The water took in 77% of the energy used to reheat it (its recovery efficiency).

All of its test figures are shared by 3 other basic models. Of those, one or more are under the AMERICAN STANDARD WATER HEATERS and Lennox brands. For the full group, see the AMERICAN STANDARD WATER HEATERS PV40SLN*.

In one state, one rebate program may accept it.