Fogatti FDG-CS120S vs Noritz NR662-OD-NG: which uses less energy?
At the medium draw pattern the Fogatti FDG-CS120S uses 134 therms a year and the Noritz NR662-OD-NG 135 — 2 therms (1%) less, about 16 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.
| Figure | Fogatti FDG-CS120S | Noritz NR662-OD-NG |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.83 (better) | 0.82 |
| Energy use per year (therms) | 134 (better) | 135 |
| Max flow (GPM) | 3.3 | 3.6 |
| Installed cost range | $1,792–$2,743 | $1,745–$2,687 |
| ENERGY STAR certified | not matched | not matched |
What it costs to run
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 Fogatti FDG-CS120S if running cost matters most: it uses 2 therms less a year on the same test.
- Pick the Noritz NR662-OD-NG if you run more fixtures at once: it lists 3.6 GPM against 3.3.
- Neither if you need more than 3.6 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
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Fogatti FDG-CS120S
Its filed figures, class position and running cost on your ZIP.
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Noritz NR662-OD-NG
Its filed figures, class position and running cost on your ZIP.