Lennox WHGS040S40NANE****
0.6 UEF DOE CCD · 2026-09-19Grade F: 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 Lennox WHGS040S40NANE****, a gas tank heater, it uses 185 therms of natural gas a year at the medium draw pattern. A draw pattern is the standard daily hot-water usage DOE tests against. The figure equals the class median of 185 therms across 288 gas tank models at the same pattern.
Energy use per year
185 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 equal to the median of 185 therms for the 288 models registered in the same heater type and draw pattern; it ranks 89 of 288, lowest energy first.
Solid line: this model (185 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
- 0.6 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
- 62 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
$1,410–$2,162 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
-
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 40-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 gas tank water heaters
Gas-fired storage tanks, every size and draw pattern on file.
-
Every Lennox model on file
What this brand files, by heater type.
UEF 0.6 · Grade F Price it on your ZIP
The 185 therms figure is calculated by this site. The registry does not list it. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the daily hot-water draw in DOE's test for the medium draw pattern. The registry lists a UEF of 0.6 for this model, from DOE CCD data retrieved 2026-09-19. The figure describes use at the federal test's draw, not in a particular home. A household that uses more or less hot water than the test assumes will use a different amount of gas. That amount is not available on this page. The steps behind the figure are set out in our method for calculating annual energy and running cost.
Among the 288 models registered as a gas tank at the medium draw pattern, this model ranks 89th lowest in energy use. That puts it in the second-lowest quarter of its class. Its difference from the class median of 185 therms is 0 therms, so its test-draw energy use equals the median. The medium pattern stands for a typical mid-sized household. The registry lists a first hour rating, the gallons of hot water available in the first hour from a full tank, of 62 gallons. It also lists a rated volume of 38 gallons. A home that regularly needs more than 62 gallons in its busiest hour falls outside what this rating covers. Models ranked ahead of it in the class use less gas at the same test draw. You can compare them by finding a same-class replacement by model number.
The running cost is not stated in this text. It depends on the average residential gas price in your state, so the page calculates it from your ZIP. The calculation starts from the same 185 therms at the medium draw pattern. Any cost shown therefore applies only at the federal test's draw, not to your household's actual use. To see the figure for your own rate, use the water heater running cost calculator for your ZIP. The installed price range appears in its own block, with its source and date. It is a modeled installed-cost range, not a quote from an installer. This page gives no energy figure for other draw patterns, because the registry rates this model only at the medium pattern.
DOE CCD · 2026-09-19