DoesTheMath

Noritz NRC661A-DV-NG vs Ruud RTGH-68DVLN-3: which uses less energy?

At the medium draw pattern the Ruud RTGH-68DVLN-3 uses 123 therms a year and the Noritz NRC661A-DV-NG 125 — 1 therms (1%) less, about 14 therms over ten years. Both are filed as a gas tankless unit, so the comparison holds. Enter your ZIP below to price the difference.


Side by side

Compared within one class only: models filed as a gas tankless unit at the medium draw pattern.

Filed and computed figures
Figure Noritz NRC661A-DV-NG Ruud RTGH-68DVLN-3
UEF (Uniform Energy Factor) 0.89 0.9 (better)
Energy use per year (therms) 125 123 (better)
Max flow (GPM) 3.4 3.5
Installed cost range $2,075–$3,074 $2,122–$3,129
ENERGY STAR certified not matched not matched
DOE CCD · 2026-09-19

What it costs to run

Noritz NRC661A-DV-NG: 125 therms a year Ruud RTGH-68DVLN-3: 123 therms a year

Noritz NRC661A-DV-NG — 125 therms a year Ruud RTGH-68DVLN-3 — 123 therms a year

Ruud RTGH-68DVLN-3 is 2 therms a year lower than Noritz NRC661A-DV-NG.

DOE CCD · 2026-09-19

Report an issue with this number

Enter your ZIP to price both units on the same rate where you live.


Reliability

Not published: Reliability, failure rates and each model’s actual warranty term.

The registries these figures come from certify energy performance under a federal test; none of them records how long a unit lasts or how often it fails, so this page does not rank the two on reliability.

What is here instead:

  • The filed efficiency, capacity and tank size of both models, side by side below.
  • The actual warranty term is printed in each model’s documentation, not in any registry.

Which should you pick?

  • Pick the Ruud RTGH-68DVLN-3 if running cost matters most: it uses 1 therms less a year on the same test.
  • Pick the Noritz NRC661A-DV-NG if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Ruud RTGH-68DVLN-3.
  • Neither if you need more than 3.5 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.

Each model on its own