A. O. SMITH ENT-40 1**
0.92 UEF DOE CCD · 2026-09-19Grade G: where this UEF sits among the 426 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
An electric tank, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
If you are checking the A. O. SMITH ENT-40 1**, an electric tank, it uses 3,531 kWh of electricity a year at the medium draw pattern. The draw pattern is the standard daily hot-water usage DOE tests against. That figure differs by 0 kWh from the median of the 426 comparable models, which is 3,531 kWh.
Energy use per year
3,531 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 3,531 kWh for the 426 models registered in the same heater type and draw pattern; it ranks 213 of 426, lowest energy first.
Solid line: this model (3,531 kWh). Dashed line: the class median.
Min 773 kWh Median 3,531 kWh Max 3,569 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
- 0.92 DOE CCD · 2026-09-19 Compared only with other models registered as an electric tank at the medium draw pattern.
- Draw Pattern the standard daily usage profile DOE tests the unit against
- Medium 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
- 53 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) · 2026-04-01Safety 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 A. O. SMITH model on file
What this brand files, by heater type.
UEF 0.92 · Grade G Price it on your ZIP
This site calculates the 3,531 kWh figure; the registry does not publish it. The calculation uses the registry's UEF, the ratio of hot water delivered to energy used, and the daily hot-water draw that the DOE test sets for the medium draw pattern. This unit's UEF is 0.92. The registry value comes from the DOE CCD and was retrieved 2026-09-19. The figure therefore holds only at the test's draw. A household that uses more or less hot water will use a different amount of electricity. The steps behind this calculation are set out in how the annual cost is calculated.
Among the 426 models registered as an electric tank at the medium draw pattern, this one ranks 213th lowest in energy use. Its 3,531 kWh equals the class median of 3,531 kWh, a difference of 0 kWh. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 53 gallons. Its rated volume is 36 gallons. DOE uses the medium pattern for a typical family household. The rating does not show how the unit performs for a household that needs more than 53 gallons in its busiest hour. To see other units in the same class, use the same-class replacement search by model number.
The running cost is not written here, because it depends on your own utility's electricity rate. The same 3,531 kWh costs a different amount under each tariff, so a figure given without your rate would be an estimate. The page calculates the cost from your ZIP code instead. The cost calculator for your own ZIP does the same for other models. The installed price range appears in its own block with its source and date. It is a modeled range, not a quote. This page does not know your household's actual hot-water use. If your use differs from the medium pattern, your energy use and cost will differ from the 3,531 kWh shown.
DOE CCD · 2026-09-19