ARISTON GSN40T2-3-*
0.59 UEF DOE CCD · 2026-09-19Grade G: where this UEF sits among the 288 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set
A gas tank, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).
If you are checking the ARISTON GSN40T2-3-* gas tank water heater, it uses 188 therms of natural gas a year. That figure is for the medium draw pattern, the standard daily hot-water usage DOE tests against. It is 3 therms above the 185 therms median of the 288 gas tank models registered at that draw pattern.
Energy use per year
188 therms 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 natural gas rate where you live.
That is above the median of 185 therms for the 288 models registered in the same heater type and draw pattern; it ranks 186 of 288, lowest energy first.
Solid line: this model (188 therms). Dashed line: the class median.
Min 148 therms Median 185 therms Max 194 therms
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
- 0.59 DOE CCD · 2026-09-19 Compared only with other models registered as a gas 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
- 70 gal DOE CCD · 2026-09-19
- Rated Storage Volume the tank size in gallons
- 38 gal DOE CCD · 2026-09-19
What it costs to install
$1,351–$2,012 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 gas tank water heaters
Gas-fired storage tanks, every size and draw pattern on file.
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Every ARISTON model on file
What this brand files, by heater type.
UEF 0.59 · Grade G Price it on your ZIP
The registry does not print the 188 therms figure. This site calculated it from two inputs. The first is the registry's UEF, the ratio of hot water delivered to energy used, which is 0.59 for this model. The second is the DOE test's daily hot-water draw for the medium draw pattern. Both come from the DOE Compliance Certification Database (CCD), retrieved 2026-09-19. The page on how the annual figure is calculated describes each step. Among the 288 gas tank models at the medium draw pattern, this one ranks 186th lowest for energy use. The figure applies only at the test's daily draw. This page has no data on gas use for a household that uses more or less hot water than the test assumes.
The tank's rated volume is 38 gallons. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 70 gallons. That rating is the figure to check against a household's busiest hour of hot-water use. The medium draw pattern represents a typical household's daily use. The 188 therms figure therefore applies most closely to homes whose daily use is near that test draw. A plumber or seller comparing this unit with another model should compare both at the same draw pattern. Otherwise the two annual figures do not describe the same test. The same-class replacement lookup by model number lists other gas tank models registered at the medium draw pattern.
If lower gas use at the medium draw pattern is the priority, note that this unit ranks 186th of 288. Models ranked ahead of it use less energy at the same test draw. This page does not give their individual figures. For a household whose hot-water use differs from the medium test, the selector by fuel, space and size filters by those needs instead. The running cost is not written in this text, because it depends on the reader's state average residential gas price. The cost calculator for your own ZIP applies that rate to the 188 therms figure. The installed price range appears in a separate block with its source and date. It is a modeled range, not a quote.
DOE CCD · 2026-09-19