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Lennox WHES040L45SN240B****

Lennox WHES040L45SN240B**** 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 AMERICAN STANDARD WATER HEATERS ENS40L-*.

Storage volume
36gallons
UEF
0.92Uniform energy factor
First-hour rating
46gallonsHot water in the first hour
See it among every electric storage model

Advertised and certified figures

Lennox WHES040L45SN240B****: advertised and certified
Lennox WHES040L45SN240B****: advertised and certified Size: advertised 40 gal, certified 36 gal (advertised nominal size, certified storage volume). UEF: advertised 0.92, certified 0.92. First-hour rating: advertised 46 gal, certified 46 gal. Size · advertised nominal size, certified storage volume Advertised 40 gal Certified 36 gal UEF Advertised 0.92 Certified 0.92 First-hour rating Advertised 46 gal Certified 46 gal
FigureAdvertisedCertifiedAdvertiserRead
Size 40 gal, nominal size 36 gal storage volume Lennox Read Oct 5, 2026
UEF 0.92 0.92 Lennox Read Oct 5, 2026
First-hour rating 46 gal 46 gal Lennox Read Oct 5, 2026

Certified figures by listed model

Model numberStorage volume (gal)UEFFirst-hour rating (gal)Recovery efficiencyDraw pattern
WHES040L45SN240B****360.924698%Low

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

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 46 gallons in the test (its first-hour rating). Reheating lets it give 10 gallons beyond the 36 gallons in its tank. Among 477 electric storage models, 368 have a higher first-hour rating. Among electric storage models, the median first-hour rating is 55 gallons.

In tests, 92% of the energy it uses ends up as hot water (UEF 0.92). Its test ran at the low level of daily hot water use. Its UEF is lower than that of 12 of the 157 electric storage models with its draw pattern. For its type and draw pattern, its UEF sits at the median. When it reheats water in the test, 98% of the energy it uses ends up in the water.

There are 2 more basic models with the same test figures. Those basic models are sold with AMERICAN STANDARD WATER HEATERS and Ariston as their brand names. You can find the whole group on the page for the AMERICAN STANDARD WATER HEATERS ENS40L-*.

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.