ARISTON ENS40LU-*
0.91 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).
At the low draw pattern, the standard daily hot-water usage DOE tests against, ARISTON ENS40LU-* uses 2,466 kWh of electricity a year. The low pattern describes a one- or two-person household. That is 27 kWh above the class median of 2,439 kWh among 163 electric tank models at the same draw pattern.
Energy use per year
2,466 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 88 of 163, lowest energy first.
Solid line: this model (2,466 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
- 0.91 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
- 41 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
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 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 ARISTON model on file
What this brand files, by heater type.
UEF 0.91 · Grade G Price it on your ZIP
The figure of 2,466 kWh was computed by this site, not by the registry. It uses the registry's UEF, the ratio of hot water delivered to energy used, which is 0.91 for this model. That UEF is applied to the DOE test's daily hot-water draw for the low draw pattern. The energy figure comes from DOE CCD, retrieved on 2026-09-19. Its rank is 88th lowest energy use of 163, in the second-highest quarter of its class for energy use. Its use sits 27 kWh above the class median of 2,439 kWh. The comparison covers only electric tank models registered at the low draw pattern.
Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 41 gallons. The rated volume is 36 gallons. The 2,466 kWh figure applies only to the low draw pattern, which is a one- or two-person household. For a household with higher hot-water use, the annual energy at a different draw pattern is not available on this page. Readers comparing other sizes can use the selector by fuel, space and size. A same-class replacement for ARISTON ENS40LU-* can be found with the same-class replacement search by model number.
Running cost depends on the electricity rate the reader pays, so this text states no amount. It follows from 2,466 kWh at the low draw pattern and the reader's own tariff. The cost calculator on your own ZIP applies the utility rate for that ZIP to this energy figure. The method behind the annual cost is described separately. An installed price range is not published for this model. Its ratings lie outside the range the cost database's model was fitted on, so the range is not stretched past it.
DOE CCD · 2026-09-19