A. O. SMITH ENS-50 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 listing, the A. O. SMITH ENS-50 1**, an electric tank, uses 3,531 kWh a year at the medium draw pattern, the standard daily hot-water usage DOE tests against. That equals its class median of 3,531 kWh, a difference of 0 kWh, and ranks 213th lowest of 426 models.
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
- 57 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 46 gal DOE CCD · 2026-09-19
What it costs to install
$1,736–$2,053 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 50-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 model's figure of 3,531 kWh is computed by this site, not by the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, of 0.92 with the daily hot-water draw that the DOE test applies to the medium draw pattern. The fuel is electricity, and the source is DOE CCD, retrieved 2026-09-19. Because the test fixes the draw, the figure is a basis for comparison and does not predict what any single home will use. The class is the 426 models registered as an electric tank at this pattern, and its median is 3,531 kWh. The difference from that median is 0 kWh, and the model ranks 213th lowest, in the second-lowest quarter of its class for energy use.
The energy figure applies only to the medium draw pattern. A household that uses more or less hot water than that pattern should not read 3,531 kWh as its own, and this page has no figure for other patterns. The registry also lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 57 gallons, and a rated volume of 46 gallons. These two values describe capacity, and they are separate from the 3,531 kWh figure. To compare options by fuel, space and size, use the water heater selector. To see units in the same class as A. O. SMITH ENS-50 1**, find a same-class replacement by model number.
The running cost is not stated in this text, because it depends on your own utility electricity tariff. Multiplying 3,531 kWh by your rate gives the yearly cost at the medium draw pattern, and your rate is not available on this page. The cost calculator on your own ZIP does this calculation for you. The steps behind it are described in how the annual cost is calculated. Because this model sits at the class median of 3,531 kWh, its yearly energy use is the same as the median figure, so at any single rate the cost would also match the median. A modeled installed-cost range is shown in its own block with its source and date. It is not a quote, and it is not restated here.
DOE CCD · 2026-09-19