A. O. SMITH ENS-30 1**
0.89 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).
The A. O. SMITH ENS-30 1** uses 2,522 kWh a year at the low draw pattern, the standard daily hot-water usage DOE tests against. If you are checking this model, low describes a small household. That is 83 kWh above the class median of 2,439 kWh, and it ranks 143rd lowest of 163 models.
Energy use per year
2,522 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 143 of 163, lowest energy first.
Solid line: this model (2,522 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
- 0.89 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
- 47 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 27 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 30-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 0.89 · Grade G Price it on your ZIP
The registry lists a UEF, the ratio of hot water delivered to energy used, of 0.89 for this model. This site combined that UEF with the DOE test's daily hot-water draw for the low draw pattern. The result is 2,522 kWh of electricity a year. The registry itself does not publish that figure. Details are in the annual cost methodology. The figure applies only at the federal test's draw, so a home that uses more or less hot water will differ. The class median for the 163 electric tank models at this draw pattern is 2,439 kWh. This model sits 83 kWh above it, in the highest quarter of its class for energy use.
The first hour rating, the gallons of hot water available in the first hour from a full tank, is 47 gallons. The rated volume is 27 gallons. The registry lists the model at the low draw pattern, which describes a small household. A household that draws more hot water than the test assumes would see use that differs from 2,522 kWh. The data here do not say by how much. A larger household can compare options in the water heater selector by fuel, space and size. The rank of 143rd lowest of 163 applies only to this draw pattern, not to tanks tested at other patterns.
Running cost depends on your own electricity tariff, so this text gives no cost figure. The cost calculator applies the rate for your ZIP to 2,522 kWh. The same energy use therefore costs different amounts in different places. The installed price range is not published. This model's ratings lie outside the range the cost database's model was fitted on. That range is not stretched past its limit. To compare with a same-class unit, you can find a same-class replacement by model number, starting from ENS-30 1**. The energy figure comes from DOE CCD, retrieved 2026-09-19.
DOE CCD · 2026-09-19