Lennox WHES040L45TN240S****
0.91 UEF DOE CCD · 2026-09-19Grade 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).
If you are checking the listing for Lennox WHES040L45TN240S****, its annual energy use is 2,466 kWh of electricity at the low draw pattern, the standard daily hot-water usage DOE tests against. That is 27 kWh above the class median of 2,439 kWh across 163 electric tank models.
Energy use per year
2,466 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 above the median of 2,439 kWh for the 163 models registered in the same heater type and draw pattern; it ranks 88 of 163, lowest energy first.
Solid line: this model (2,466 kWh). Dashed line: the class median.
Min 724 kWh Median 2,439 kWh Max 2,550 kWh
What it costs to run where you live
What the registry files
- UEF (Uniform Energy Factor) how much hot water you get for each unit of energy the heater uses
- 0.91 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
- 41 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
Not published: Installed cost range
This model's UEF lies outside the range NLR REMDB's cost model was fitted on, and the range is not stretched past it.
The annual energy figure on this page does not depend on this range and is unaffected.
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 · 2026-09-24What these figures mean
How this compares
The closest models in the same class — same fuel, type and draw pattern.
Keep going
How every figure on this page is calculated
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Find what replaces your water heater
Enter the model number off your old unit and see what is on file today, with the yearly cost difference.
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Find a water heater that fits
Three questions — fuel, hot water need, install space — narrow every model on file to the ones that fit.
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What a water heater costs to run
Prices a unit's efficiency against your own utility's filed tariff for your ZIP code.
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Is a 40-gallon water heater enough?
Answered from what models in this size actually file.
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Water heaters
Every model on file with the Department of Energy, by heater type.
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All electric resistance tank water heaters
Electric tanks that file a UEF below 2.0 — heated by elements, not a heat pump.
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Every Lennox model on file
What this brand files, by heater type.
UEF 0.91 · Grade G Price it on your ZIP
The figure of 2,466 kWh is calculated by this site and is not a registry value. It uses the registry's UEF, the ratio of hot water delivered to energy used, which is 0.91 for this model. It also uses the daily hot-water draw that the DOE test sets for the low draw pattern. The source is DOE CCD, retrieved 2026-09-19. The fuel is electricity, since the unit is an electric tank. The figure holds only at that test draw. Actual use in a home will differ with the hot water the household draws.
Among the 163 models registered as an electric tank at the low draw pattern, this unit ranks 88th lowest in energy use. That puts it in the second-highest quarter of its class for energy use. Its figure is 27 kWh above the class median of 2,439 kWh. The listing gives a first hour rating, the gallons of hot water available in the first hour from a full tank, of 41 gallons. The rated volume is 36 gallons. These ratings fit a household whose use matches the low draw pattern. A household with heavier use falls outside the condition of the figure. The selector by fuel, space and size lets you compare other options.
Running cost is not stated in the text because it depends on your own electricity tariff. The cost calculator applies the rate for your ZIP to 2,466 kWh. The gap of 27 kWh from the class median also converts to a cost only at your rate. How the annual cost is calculated is documented separately. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on. That range is not stretched past its limits. To look for a same-class unit, search by model number starting from WHES040L45TN240S****.
DOE CCD · 2026-09-19