A Reddit thread comparing the Rinnai RU199iN against the Navien NPE-240A2 drew more than 40 replies from real installers and homeowners, with one plumber commenting on pricing specifically: “Kinda odd because I sell these units to plumbers for a living. The Rinnai would cost an…” before the thread continues into a detailed back and forth about which brand actually holds up better long term. This rivalry is one of the most searched comparisons in the entire condensing tankless category, and it’s worth settling with real current numbers.
Rinnai’s current-generation RXP199iN (199,000 BTU, up to 11.1 GPM, around $1,735.53) and Navien’s NPE-240A2 (199,900 BTU, up to 11.2 GPM at a 67°F rise, priced $1,884 to $2,196.93 across plumbing supply retailers) are extremely closely matched on raw capacity, with Navien generally running somewhat higher in price and Rinnai offering broader big-box and online retail availability. Both are well-regarded condensing units in the same output class, and the choice often comes down to installer familiarity and specific feature preferences rather than a clear capacity advantage for either brand.
Side-by-Side Comparison
| Spec | Rinnai RXP199iN | Navien NPE-240A2 |
|---|---|---|
| BTU rating | 199,000 | 199,900 |
| Max flow rate | Up to 11.1 GPM | Up to 11.2 GPM (at 67°F rise) |
| UEF/Energy Factor | Not listed at this exact figure | 0.95 UEF |
| Recirculation pump | Built in | Available depending on configuration |
| Price range (2026) | ~$1,735.53 (Amazon) | $1,884-$2,196.93 (plumbing supply retailers) |
| Where sold | Amazon, major retailers, HVAC suppliers | Primarily specialty plumbing/HVAC suppliers |
Capacity Is Essentially a Wash
Both units land within 900 BTU and 0.1 GPM of each other at their respective maximum ratings, a difference so small it’s unlikely to matter in real-world household use. If you’re choosing based purely on raw heating capacity, neither brand holds a meaningful edge over the other in this specific size class.
Price Favors Rinnai, Generally
Based on current pricing across multiple sources, the Navien NPE-240A2 tends to run somewhat higher than Rinnai’s RXP199iN, with Navien pricing from specialty suppliers landing in the $1,884 to $2,196.93 range compared to Rinnai’s roughly $1,735.53 Amazon price. This isn’t universal, pricing varies by retailer and region, but it’s a consistent pattern across the sources checked for this comparison.
Availability Favors Rinnai for DIY-Minded Buyers
Rinnai’s current lineup, including the RXP199iN and RX199iN, is readily available through Amazon and other major online retailers, making it straightforward to research, compare, and purchase without going through a specialty plumbing supplier. Navien’s NPE-240A2, by contrast, appears primarily through dedicated plumbing and HVAC supply retailers based on the sources checked, which may mean more direct professional involvement in the purchasing process, though this can also mean more specialized support during that process.
What Real Installers Say
The Reddit discussion referenced above reflects a broader pattern in installer conversations: both brands have loyal followings among plumbers, and preference often comes down to which brand a given installer has more experience servicing, rather than one being objectively superior. This matters because your installer’s familiarity with a specific brand can affect installation quality and troubleshooting speed down the line, a factor worth weighing alongside the raw spec comparison.
Which Should You Choose?
If you want the more widely available option with broader online retail access and the built-in recirculation pump already included, the Rinnai RXP199iN is the more straightforward buy. If your installer has strong Navien experience and recommends the NPE-240A2 specifically, its nearly identical capacity means you’re not sacrificing performance by going that route, you may simply be paying a bit more depending on current regional pricing.
For a deeper look at what makes the Rinnai side of this comparison a genuine upgrade from the original RU199iN, see our RU199iN vs RXP199iN comparison.
Rinnai RXP199iN Condensing Tankless Water Heater with Built-In Recirculation Pump - View on Amazon
The Bottom Line
Rinnai’s RXP199iN and Navien’s NPE-240A2 are closely matched on core capacity, with Rinnai generally running less expensive and more widely available through online retail, while Navien commands a premium price through specialty suppliers. Neither brand holds a decisive capacity advantage in this size class.
Frequently Asked Questions
Which is better, Rinnai or Navien? Both brands offer strong condensing tankless units in this capacity class with nearly identical specs. The choice often comes down to price, availability, and your installer’s brand familiarity rather than a clear performance winner.
Is the Navien NPE-240A2 more expensive than the Rinnai RXP199iN? Generally yes, based on current pricing, the NPE-240A2 runs $1,884 to $2,196.93 through specialty suppliers compared to around $1,735.53 for the Rinnai RXP199iN on Amazon.
Do Rinnai and Navien units have similar flow rates? Yes, extremely close, the RXP199iN is rated up to 11.1 GPM while the NPE-240A2 is rated up to 11.2 GPM at a 67°F temperature rise.
Where can I buy a Navien NPE-240A2? Primarily through specialty plumbing and HVAC supply retailers, based on available sourcing, rather than major online retailers like Amazon.
Is Rinnai easier to buy than Navien? Yes, Rinnai’s current lineup is readily available through Amazon and other major retailers, while Navien’s NPE-240A2 appears to be sold primarily through dedicated plumbing supply channels.
Does the Rinnai RXP199iN have a recirculation pump built in? Yes, this is a standard feature of the RXP199iN, addressing a common gap from the older RU199iN generation.
Which brand do plumbers prefer? Based on forum discussions among installers, preference varies significantly by individual experience and regional familiarity, rather than one brand being universally preferred.
Is a higher UEF rating better? Generally yes, a higher UEF (Uniform Energy Factor) indicates better overall efficiency, though the practical difference between closely rated units in the same class is often small.
Should I choose based on price alone? Given how closely matched these units are on capacity, price and installer familiarity are reasonable primary factors, provided you’re comparing units in the same BTU and GPM class.
Can I get the Navien equivalent of the Rinnai RXP199iN’s recirculation pump? Navien offers recirculation-capable configurations depending on the specific model and installation setup, worth confirming directly with a Navien-familiar installer or supplier for your specific needs.
References
- Navien official product specifications for the NPE-240A2, accessed July 2026: https://www.navieninc.com
- SupplyStop.com, VAMAC Inc., and United Plumbing & Fire Supply pricing and specifications for the Navien NPE-240A2, accessed July 2026
- Amazon.com live pricing and specifications for the Rinnai RXP199iN, accessed July 2026
- Reddit community discussion comparing Rinnai and Navien tankless water heaters, accessed July 2026