DoesTheMath

Noritz NRC661A-DV-NG

0.89 UEF DOE CCD · 2026-09-19
D

Grade D: where this UEF sits among the 80 models in its class, lowest (G) to highest (A). A position, not an official label. How the grade is set

A gas tankless unit, medium draw pattern (a typical three- or four-person household, about 55 gallons on a busy morning).

Verifying this model's energy use? At the medium draw pattern (the standard daily hot-water usage DOE tests against), the Noritz NRC661A-DV-NG uses 125 therms of natural gas a year. That is 10 therms below the 135 therms median of 80 gas tankless models, 20th lowest.


Energy use per year

125 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 below the median of 135 therms for the 80 models registered in the same heater type and draw pattern; it ranks 20 of 80, lowest energy first.

This model: 125 therms

Solid line: this model (125 therms). Dashed line: the class median.

Min 114 therms Median 135 therms Max 137 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
0.89 DOE CCD · 2026-09-19 Compared only with other models registered as a gas tankless unit at the medium draw pattern.
Draw Pattern the standard daily usage profile DOE tests the unit against
Medium DOE CCD · 2026-09-19
Maximum Gallons Per Minute how many gallons a minute it can heat while running continuously
3.4 gal/min DOE CCD · 2026-09-19

What it costs to install

$2,075–$3,074 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 125 therms figure is natural gas at the medium draw pattern, at the federal test's daily hot-water draw. It is not a measurement of any particular home. This site computed it, not the registry, from the registry's UEF, the ratio of hot water delivered to energy used, which is 0.89 for this unit, and the DOE test's daily draw for this pattern. The source is DOE CCD, retrieved 2026-09-19. The maximum flow rate in gallons per minute is 3.4. That is a capacity rating, and it is not an input to the annual energy figure. How the annual cost is calculated sets out the method. A different draw pattern would give a different annual figure, and this page does not show one.

Among the 80 models registered as a gas tankless unit at the medium draw pattern, this model ranks 20th lowest in energy use. Its 125 therms sits 10 therms below the class median of 135 therms, which places it in the lowest quarter of its class. The comparison suits a reader whose hot-water use resembles a typical household on a busy morning and who wants to check gas use within the same class. It says less for a household whose use differs from that pattern, because the figure is tied to the federal test's draw. A gap of 10 therms compares test-based figures only, and this page does not show whether it matters in a given home. To look at other units in the same class, use a same-class replacement by model number.

The text gives no running cost. The cost depends on your state's average residential gas price, and that price is not part of this model's data. To check it yourself, apply your local gas price to 125 therms, or use the cost calculator on your own ZIP, which does this on the page. The installed-cost range appears in its own block with its source and date, and it is a modeled range, not a quote. The energy figure was retrieved 2026-09-19, so registry changes after that date are not reflected. Readers who need a different fuel, space or size can use the water heater selector. For a unit at 20th lowest of 80, the cost result will still move with the rate you enter.

DOE CCD · 2026-09-19

How this compares

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


Keep going

UEF 0.89 · Grade D Price it on your ZIP