DoesTheMath

LOCHINVAR GDV-40 3**

0.6 UEF DOE CCD · 2026-09-19
F

Grade 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).

For a check against the registry, LOCHINVAR GDV-40 3** uses 185 therms of natural gas a year. That figure is for the medium draw pattern, the standard daily hot-water usage DOE tests against. It equals its class median of 185 therms, a difference of 0 therms, among 288 gas tank models.


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.

This model: 185 therms

Solid line: this model (185 therms). Dashed line: the class median.

Min 148 therms Median 185 therms Max 194 therms

DOE CCD · 2026-09-19

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What it costs to run where you live

Enter your ZIP to see what this unit costs to run a year at your state’s average natural gas price.


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
64 gal DOE CCD · 2026-09-19
Rated Storage Volume the tank size in gallons
39 gal DOE CCD · 2026-09-19

What it costs to install

$1,424–$2,199 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) · 2026-04-01

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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 · 2026-09-24

What these figures mean

The annual figure of 185 therms is computed by this site, not taken from the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, which is 0.6 for this model, with the daily hot-water draw the federal test assigns to the medium draw pattern. The source data is the DOE CCD, retrieved 2026-09-19. The figure is natural gas use for a 39-gallon gas tank under that test draw only. A household that draws more or less hot water than the test will use a different amount, and this page does not estimate it. The calculation method is documented separately.

Among the 288 models registered as a gas tank at the medium draw pattern, this unit ranks 89th lowest for energy use, in the second-lowest quarter of its class. Its 185 therms equals the class median of 185 therms, so the difference is 0 therms. Energy use at the class median suits a reader who wants a unit that neither saves nor spends more gas than the typical model under the test draw. Its first hour rating, the gallons of hot water available in the first hour from a full tank, is 64 gallons. A household whose busiest hour needs more hot water than that is not served by this rating. The water heater selector filters by fuel, space and size.

The running cost is not written in this text because it depends on your state average residential gas price, which is not in the data here. The cost calculator takes your ZIP and applies that price to 185 therms. Because the figure is tied to the medium draw pattern, the result holds only at that test draw. The modeled installed-cost range is shown in its own block with its source and date; it is a range, not a quote. To compare against another unit of the same class, the replacement finder starts from a model number such as GDV-40 3**, listed by LOCHINVAR.

DOE CCD · 2026-09-19

How this compares

The closest models in the same class — same fuel, type and draw pattern.


Keep going

UEF 0.6 · Grade F Price it on your ZIP