DoesTheMath

Lennox WHES040L45SN240B****

0.92 UEF DOE CCD · 2026-09-19
G

Grade G: where this UEF sits among the 163 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set

An electric tank, low draw pattern (a one- or two-person household).

Checking the Lennox WHES040L45SN240B****? At the low draw pattern, the standard daily hot-water usage DOE tests against, this electric tank uses 2,439 kWh a year. Low draw pattern means a one- or two-person household. That equals the class median of 2,439 kWh, a difference of 0 kWh, among 163 registered models.


Energy use per year

2,439 kWh a year

Computed by this site from the registry's UEF and the federal test's daily hot-water draw for this draw pattern. What it costs depends on the electricity rate where you live.

That is equal to the median of 2,439 kWh for the 163 models registered in the same heater type and draw pattern; it ranks 19 of 163, lowest energy first.

This model: 2,439 kWh

Solid line: this model (2,439 kWh). Dashed line: the class median.

Min 724 kWh Median 2,439 kWh Max 2,550 kWh

DOE CCD · 2026-09-19

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What it costs to run where you live

Enter your ZIP to see what this unit costs to run a year on your own utility’s electricity rate.


What the registry files

UEF (Uniform Energy Factor) how much hot water you get for each unit of energy the heater uses
0.92 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tank at the low draw pattern.
Draw Pattern the standard daily usage profile DOE tests the unit against
Low DOE CCD · 2026-09-19
First Hour Rating how many gallons of hot water the unit can deliver in one hour, starting from a full tank
46 gal DOE CCD · 2026-09-19
Rated Storage Volume the tank size in gallons
36 gal DOE CCD · 2026-09-19

What it costs to install

$1,591–$1,802 installed

Not a quote — a modeled range of what installers have charged for this class of unit; your price will vary with labor rates, access, and local code requirements.

Escalation indexes: equipment (BLS PPI) latest available: August 2026; labor (BLS ECI) latest available: April 2026 to June 2026.

NLR REMDB (BLS PPI/ECI escalated) · 2026-04-01

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Safety record

No CPSC recall names this model.

Checked against the CPSC recall database. CPSC does not publish a model-level match for this product category, so this list is curated by hand from the manufacturer's recall filings.

CPSC · 2026-09-24

What these figures mean

The annual figure of 2,439 kWh is electricity use for the Lennox WHES040L45SN240B**** at the low draw pattern. This site computed it, not the registry. It starts from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.92 here. It then applies the DOE test's daily hot-water draw for this pattern. The source is DOE CCD, retrieved 2026-09-19. The class median for the 163 electric tank models at the low draw pattern is 2,439 kWh, so the difference is 0 kWh. The rank is 19th lowest energy use of 163, in the lowest quarter of the class. This page's data does not show why a figure equal to the median ranks in the lowest quarter, so that reason is not available. The method for the annual figure is documented separately.

The low draw pattern describes a one- or two-person household, and that is the household this figure fits. The model's first hour rating, the gallons of hot water available in the first hour from a full tank, is 46 gallons. Its rated volume is 36 gallons. These are the two capacity values to compare with a household's hot-water demand. The figure of 2,439 kWh does not describe larger households, because it is tied to the low draw pattern. Energy use at other draw patterns is not available for this model on this page. To compare by fuel, space and size, use the water heater selector, or find a same-class replacement by model number.

Running cost is not stated in this text because it depends on your own utility electricity tariff. The cost is 2,439 kWh multiplied by your rate per kilowatt-hour, and that rate differs between utilities. The cost calculator on your own ZIP applies your rate to this model's figure. The result carries the same limits as the energy figure. It reflects the DOE test's daily draw for the low draw pattern, and measured use in a specific home is not available. It also leaves out installation. A modeled installed-cost range is shown in its own block on this page with its source and date, and it is a range, not a quote.

DOE CCD · 2026-09-19

How this compares

The closest models in the same class — same fuel, type and draw pattern.


Keep going

UEF 0.92 · Grade G Price it on your ZIP