Rinnai and Navien are two widely installed tankless brands, and both show up in San Diego installer listings. Here is how their popular residential lines compare, using only what the manufacturers publish.
| Rinnai SENSEI RX (condensing) | Rinnai RE (non-condensing) | Navien NPE-A2 (condensing) | |
|---|---|---|---|
| Efficiency (UEF) | Up to 0.98 (RX199iN) | 0.81–0.82 | 0.95 |
| Max flow | 11.1 GPM (RX199iN) | 5.3–9.8 GPM | 11.2 GPM at a 35°F rise; 5.6 at 67°F (NPE-240A2) |
| Recirculation | Smart-Circ accessory | Optional external pump | Built-in pump and ComfortFlow buffer tank |
| Wi-Fi / app | Wi-Fi capable; Rinnai Central app | Optional control·r module | NaviLink add-on |
| Venting | PVC, CPVC or polypropylene | 3"/5" concentric | PVC, CPVC, polypropylene or stainless |
| Warranty: heat exchanger / parts / labor | 15 yr (or 12,000 hrs) / 5 yr / 5 yr if registered in 90 days | 15 yr (or 12,000 hrs) / 5 yr / 1 yr | 15 yr / 5 yr / 1 yr |
Warranty fine print that matters
- Rinnai SENSEI RX: labor drops to 1 year unless the unit is registered within 90 days; heat exchanger coverage drops to 8 years if the temperature is set above 160°F; coverage ends if the unit is moved.
- Navien NPE-A2: with uncontrolled recirculation (a pump running continuously without an aquastat), coverage drops to 5 years heat exchanger, 3 years parts, 1 year labor.
- Navien: installation by an unlicensed contractor voids the warranty, and so does buying through e-commerce channels.
Reading the flow numbers
Rinnai publishes a maximum flow; Navien publishes flow at specific temperature rises. They are not directly comparable. What matters is flow at your temperature rise: Southern California incoming water is warmer than much of the country, so a given unit delivers more hot water here. See our sizing guide.
Which to choose
Both are mainstream, well-supported brands. Pick the model that fits your flow needs and venting, whether you want built-in recirculation, and the warranty terms; then choose a licensed installer who services that brand. In San Diego's hard water, either one needs regular descaling.
General information, not professional or legal advice; follow your manufacturer's manual, and your installer and local permit office have the final word. Sources:Rinnai RX199iN product page; Rinnai SENSEI residential warranty (100000655, 10/2024); Rinnai RE series non-condensing spec sheet (6/2022); Navien NPE-2 QuickFacts (NPE2-QF001); Navien NPE-A warranty. SD Water Heaters is not affiliated with any manufacturer; brand names are used only to identify products, and codes can differ by model, so confirm in your own manual.
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