A. O. SMITH HESF-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 this water heater, the A. O. SMITH HESF-40 1** uses 3,531 kWh of electricity a year. That figure is for the medium draw pattern, the standard daily hot-water usage DOE tests against. It equals the class median of 3,531 kWh, a difference of 0 kWh, among 426 electric tanks.
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
- 64 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 37 gal DOE CCD · 2026-09-19
What it costs to install
$1,605–$1,828 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
The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.92 for this model. This site combines that value with the DOE test's daily hot-water draw for the medium draw pattern. The result is 3,531 kWh of electricity a year. The registry does not publish this figure. It is a calculation by this site, based on DOE CCD data retrieved 2026-09-19. Among the 426 electric tanks registered at the medium draw pattern, the model ranks 213th lowest for energy use. That places it in the second-lowest quarter of its class. Its difference from the median is 0 kWh.
The medium draw pattern describes a typical three- or four-person household on a busy morning. The figure fits a household close to that pattern. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 64 gallons. The rated volume is 37 gallons. A household with a different draw is not described by 3,531 kWh. The registry data gives no other draw pattern for this model on this page, so that value is not available. To compare similar units, use the water heater selector or find a same-class replacement by model number.
The running cost is not stated in the text because it depends on your own utility electricity tariff. To estimate it, multiply 3,531 kWh by your rate per kilowatt-hour. That figure applies only to the medium draw pattern. The cost calculator does this from your ZIP. The method is described in how the annual cost is calculated. The model sits 0 kWh from the class median of 3,531 kWh. Its electricity use therefore matches that of a median unit at the same rate. The installed price range appears in its own block on this page, with its source and date, as a modeled range and not a quote.
DOE CCD · 2026-09-19