Hot Water List
Menu

State ENS-40W 1**

State ENS-40W 1** is in the DOE listing as of Oct 19, 2026.

  • Electric storage water heater
  • 1 listed model

ENERGY STAR certification does not cover this type of water heater.

Its figures are also listed under A. O. Smith ENS-40W 1**.

Storage volume
37gallons
UEF
0.88Uniform energy factor
First-hour rating
41gallonsHot water in the first hour
See it among every electric storage model

Advertised and certified figures

State ENS-40W 1**: advertised and certified
State ENS-40W 1**: advertised and certified Size: advertised 40 gal, certified 37 gal (advertised nominal size, certified storage volume). Size: advertised 37 gal, certified 37 gal (certified storage volume). UEF: advertised 0.88, certified 0.88. First-hour rating: advertised 41 gal, certified 41 gal. Size · advertised nominal size, certified storage volume Advertised 40 gal Certified 37 gal Size · certified storage volume Advertised 37 gal Certified 37 gal UEF Advertised 0.88 Certified 0.88 First-hour rating Advertised 41 gal Certified 41 gal
FigureAdvertisedCertifiedAdvertiserRead
Size 40 gal, nominal size 37 gal storage volume State Read Oct 5, 2026
Size 37 gal 37 gal storage volume State Read Oct 5, 2026
UEF 0.88 0.88 State Read Oct 5, 2026
First-hour rating 41 gal 41 gal State Read Oct 5, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
EN6-40-DORSW 1**370.884198%Low

UEF is the uniform energy factor. A dash means the model has no such figure.

It holds 37 gallons in the test, 3 gallons less than its 40-gallon sold size. Starting full, it gives 41 gallons of hot water in its first hour of use. Its tank holds 37 gallons, so reheating adds 4 gallons during the first hour. Among 477 electric storage models, 429 have a higher first-hour rating. The median electric storage model gives 55 gallons in its first hour.

In the test, 12% of its energy does not reach the hot water (UEF 0.88). The daily hot water use in the test, called its draw pattern, was low. Among 157 electric storage models on its draw pattern, 151 have a higher UEF. For its type and draw pattern, the UEF runs from 0.88 to 0.95. When it reheats water in the test, 98% of the energy it uses ends up in the water.

Its test figures match those of 3 other basic models. The A. O. Smith, American, and Lochinvar brands list one or more of them. For the full group, see the A. O. Smith ENS-40W 1**.

Also listed as

They carry every figure in the table above.

Updated Oct 19, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.