A. O. SMITH ENL-40 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).
You are checking the A. O. SMITH ENL-40 1**, an electric tank. At the low draw pattern, the standard daily hot-water usage DOE tests against, it uses 2,522 kWh of electricity a year. That is 83 kWh above the 2,439 kWh median of the 163 models in its class.
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
- 50 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 35 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
-
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.
-
Find a water heater that fits
Three questions — fuel, hot water need, install space — narrow every model on file to the ones that fit.
-
What a water heater costs to run
Prices a unit's efficiency against your own utility's filed tariff for your ZIP code.
-
Is a 30-gallon water heater enough?
Answered from what models in this size actually file.
-
Water heaters
Every model on file with the Department of Energy, by heater type.
-
All electric resistance tank water heaters
Electric tanks that file a UEF below 2.0 — heated by elements, not a heat pump.
-
Every A. O. SMITH model on file
What this brand files, by heater type.
UEF 0.89 · Grade G Price it on your ZIP
This site, not the registry, computed the 2,522 kWh figure. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the low draw pattern. This model's UEF is 0.89. DOE sets the low draw pattern for a one- or two-person household. The yearly figure holds only at that test draw. This page has no figure for the model at any other daily draw. A household that uses more hot water therefore cannot read its own use from this figure. The UEF comes from the DOE CCD, retrieved 2026-09-19. The full steps are set out under how the annual cost is calculated.
Within its class, the model ranks 143rd lowest in energy use of the 163 models registered as an electric tank at the low draw pattern. That puts it in the highest quarter of its class for energy use, with the gap to the median given above. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 50 gallons. Its rated volume is 35 gallons. This page holds no ratings for the model at any other draw pattern. Whether it suits a larger household is therefore not known from this data. Anyone checking other models in the same class can find a same-class replacement by model number.
The running cost is not stated in this text. It depends on your own utility electricity tariff, and this page names no amount. The yearly cost at the low draw pattern is 2,522 kWh multiplied by that tariff. The cost calculator on your own ZIP does that step for you. The same tariff sets what the 83 kWh gap to the class median costs each year. An installed price range is not available for this model either. Its ratings lie outside the range the cost database's model was fitted on. This page does not stretch that range to cover it, so no installed price is shown.
DOE CCD · 2026-09-19