Friedrich RTG-70XLN-3 vs Navien NHW700-160SE-NG: which uses less energy?
At the high draw pattern the Friedrich RTG-70XLN-3 uses 206 therms a year and the Navien NHW700-160SE-NG 209 — 3 therms (1%) less, about 25 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 high draw pattern.
| Figure | Friedrich RTG-70XLN-3 | Navien NHW700-160SE-NG |
|---|---|---|
| UEF (Uniform Energy Factor) | 0.82 (better) | 0.81 |
| Energy use per year (therms) | 206 (better) | 209 |
| Max flow (GPM) | 4 | 4 |
| Installed cost range NLR REMDB | $1,745–$2,687 | $1,698–$2,632 |
| CPSC recall naming it CPSC | none on file | none on file |
DOE CCD · 2026-09-19 NLR REMDB · 2026-04-01 CPSC · 2026-09-24
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 above.
- No CPSC recall on file names either model (list checked 2026-09-24).
- The actual warranty term is printed in each model’s documentation, not in any registry.
Which should you pick?
- Pick the Friedrich RTG-70XLN-3 if running cost matters most: it uses 3 therms less a year on the same test.
- Pick the Navien NHW700-160SE-NG if it is the one you can get installed sooner or for less — on the filed figures it has no advantage over the Friedrich RTG-70XLN-3.
- Neither if you need more than 4 GPM at the same time — neither unit lists more. Check how to size a tankless unit by GPM.
Each model on its own
- Friedrich RTG-70XLN-3 206 therms a year
- Navien NHW700-160SE-NG 209 therms a year