ARISTON ENS40LUB 240V-3500W
0.92 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 ARISTON ENS40LUB 240V-3500W. At the low draw pattern, the standard daily hot-water usage DOE tests against, it uses 2,439 kWh of electricity a year. That equals the class median of 2,439 kWh, a difference of 0 kWh, among 163 electric tank models.
Energy use per year
2,439 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 2,439 kWh for the 163 models registered in the same heater type and draw pattern; it ranks 19 of 163, lowest energy first.
Solid line: this model (2,439 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
- 0.92 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
- 39 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
$1,591–$1,802 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 ARISTON model on file
What this brand files, by heater type.
UEF 0.92 · Grade G Price it on your ZIP
The figure of 2,439 kWh is 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 0.92 for this model. That is combined with the DOE test's daily hot-water draw for the low draw pattern. The source is DOE CCD, retrieved 2026-09-19. The figure holds only at that test draw. A household that uses more or less hot water will see a different amount, and this page has no value for it. Details are in how the annual cost is calculated.
Against the 163 electric tank models registered at the low draw pattern, this unit ranks 19th lowest in energy use. That places it in the lowest quarter of its class. The difference from the class median of 2,439 kWh is 0 kWh. The low draw pattern describes a household with low hot-water use, so the figure suits a comparison for that kind of use. The rated volume is 36 gallons. The first hour rating, the gallons of hot water available in the first hour from a full tank, is 39 gallons. A larger household may need other capacity, and this page has no data on that. Other fuels, spaces and sizes can be filtered in the selector by fuel, space and size.
The running cost is not stated here because it depends on the utility electricity tariff at the reader's address. Multiply the 2,439 kWh by the local rate per kilowatt-hour to get the yearly electricity cost at the test draw. The cost calculator on your own ZIP does this with your local rate. This model sits 0 kWh from the class median of 2,439 kWh. At the same rate, its yearly cost equals that of a median model. Installed price is shown in its own block as a modeled range, not a quote. To find a same-class replacement, enter the model number in the replacement finder.
DOE CCD · 2026-09-19