Navien Tankless Water Heater vs Rinnai, Comparison of Brand, Series, Products, Cost and Warranties

Navien and Rinnai are two leading manufacturers of gas tankless water heaters. They’re comparable in many ways but have differences worth noting too.

The brands have been reviewed separately, Rinnai here and Navien here.

This page allows you to compare Navien and Rinnai tankless water heaters – the products including GPM ratings, efficiency, price and warranties.

Navien vs Rinnai Tankless Water Heater Comparison

This table lists series, models and essential details when comparing Navien vs Rinnai tankless water heaters.

Navien Tankless Water Heaters Series Overview
Series / # of Sizes BTUs Fuel Efficiency Max GPM Location Warranty
NPN-U (3) 160K to 199K NG 81% 8.7 – 11.1 Either 5/15
NPN-E (4) 120K to 199K NG or LP 81% 8.7 – 11.1 Outdoor 5/15
NPE-A2 (3) 150K to 199K NG 95% 6.8 – 11.2 Either 5/15
NPE-S2 (4) 120K to 199K NG 96% 6.8 – 11.2 Either 5/15
Rinnai Tankless Water Heaters Series Overview
Series / # of Models BTUs Fuel Efficiency Max GPM Location Warranty
V HE (4) 120K to 192K NG or LP Up to 82% 5.6 – 9.8 Either 5/10
RL HE+ (2) 180K & 199K NG or LP Up to 83% 7.5 – 9.8 Either 5/10
RLX HE+ (1) 192K NG Up to 83% 9.8 Indoor 5/10
RUCS SE (2) 130K & 160K NG Up to 90% 6.5 – 7.5 Indoor 5/10
RUS SE (2) 130K & 160K NG or LP Up to 90% 6.5 – 7.5 Outdoor 5/10
RU SE (4) 130K to 199K NG or LP Up to 93% 7.0 – 11.0 Either 5/10
RUR SE (2) 160K & 199K NG or LP 93% 9.0 – 11.0 Either 5/10
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Warranty: The first number is the general parts warranty. The second is the length of the heat exchanger warranty. See the Warranty section below for more information.

Note on Max GPM: We don’t want to say, “forget it,” but that about sums it up. The Max gallons per minute rating for any tankless water heater is a number that yours won’t reach unless you live where incoming water is really warm.

For most of the country, especially the north or where a well brings water up from underground where it is always 55F to 60F wherever you live, your max GPMs will be about half the rated number.

Navien Tankless Water Heater Series Overview

Selection: Navien makes four series of water heaters, two are non-condensing with efficiency of 81%. Two are condensing with efficiency of 95% and 96%.


Cost: Navien tankless water heater cost for pro installation ranges from about $1,950 for a 160,000 BTU non-condensing (81% efficiency) unit to around $3,500 for a condensing (96% efficiency) Navien tankless water heater.

Both indoor and outdoor models are offered, though there is only one liquid propane (LP) unit, the NPN-E Series which can only be installed outdoors.

Only sold through dealers – That’s something DIY enthusiasts should consider. You can’t buy a new Navien tankless water heater and install it yourself. You might find the odd unit on eBay, but generally speaking, Navien water heaters are only sold as a package – the unit plus installation – by local, certified dealers.

Rinnai Tankless Water Heater Series Overview

Rinnai gives you a much wider selection of models. Navien covers the bases reasonably well, but if you prefer more options, look at Rinnai.


Selection: There are 7 Rinnai water heater series, each available in multiple sizes/capacities. Most have natural gas and propane models, and many can be installed indoors or outdoors to suit your requirements. But see the Table above – there are indoor-only and outdoor-only models, so beware of that prior to purchasing.

Efficiency: Non-condensing Rinnai tankless heaters offer efficiency up to 83%. Condensing models are up to 93% efficient, so Navien has a slight edge in the top efficiency rating.

Cost: Rinnai water heater cost ranges from available about $1,500 to $3,200, so slightly lower in cost than Navien. Of course, if you DIY the installation, you’ll save up to half the cost on labor. Just make sure you know what you’re doing, since any gas-fired appliance creates the potential for gas leaks and for the leak of exhaust that contains carbon monoxide.

Where to Buy – You can buy Rinnai tankless water heaters from a range of retail stores like Home Depot, Lowes and other building supply and hardware sellers. There are many online sellers too.

Non-condensing Water Heaters

A non-condensing tankless water heater has a single heat exchanger, so the cost is lower, but so is efficiency. And that makes operating cost 10% to 15% higher.

Rinnai V, RL and RLX Series are all “HE” units, meaning High Efficiency, which is Rinnai’s designation for non-condensing models.

Condensing Water Heaters

Rinnai RUR, RU, RUCS and RUS are condensing water heaters. The SE in each series stands for Super Efficiency – or condensing technology.

Navien NPE-A2 and NPE-S2 are condensing units.


Here are features to consider when you compare Navien vs Rinnai tankless water heaters.

Features of Tankless Water Heaters

Condensing Technology

A condensing tankless water heater is built with a second heat exchanger. In most units, the second heat exchanger is used to preheat water as it enters the heater. The result is better efficiency, which translates to lower operating costs. But the units and installation materials are more expensive

Rinnai makes condensing units from 130,000 BTU to 199,000 BTU capacity. They deliver from 6.5 to 11.0 gallons per minute, but in most parts of the country, expect 4.0 to 7.5 GPM from these models because the incoming water needs to be heated 50 degrees or more to reach 110-120F. Units with this capacity can deliver continuous hot water to 2-4 locations at a time.

Navien condensing tankless water heaters are available in 120,000 to 199,000 BTUs. GPMs are similar, so they’ll also serve up to 4 locations simultaneously.

Recirculating Technology

A major reason homeowners like tankless units is instant hot water. But it isn’t a reality without recirculating technology. In other words, water still sits in the pipe between the water heater and the outlet – a faucet or shower, for example. That water cools and must be run out of the pipe before the hot water hits.

Recirculating technology eliminates this problem. There are a couple ways this is done. In most, a pump is added to the water heater, and an extra pipe is installed.

When the water in the pipe cools, a sensor starts the water heater and pump, cycling cooled water back through the water and into the pipe again. The result is instant hot water.

This technology is typically installed to serve one or two water outlets – usually the most used. Timers control the system, so that immediate hot water is available when you’re most likely to need it. And you’re not wasting energy when it isn’t needed.

Navien: Recirculation technology is standard on the Navien NPE-2A Series and optional on the Navien NPE-2S Series. It’s not offered on the non-condensing series.

Rinnai: The RUR Series has built-in recirculation technology. It is optional on all other series, both condensing and non-condensing.


Why WiFi? It allows you to monitor and change the temperature setting and timer, if the water heater has one, on the unit.

Will you use it? Frankly, most homeowners rarely use this option, preferring to “set it and forget it” on the water heater. WiFi is more useful, for example, on a thermostat to optimize energy efficiency.

However, both brands offer WiFi connectivity.

Navien: All Navien tankless water heaters are equipped with NaviLink, the brand’s WiFi technology. This is one of the reasons for the overall higher cost of Navien water heaters.

Rinnai: WiFi is standard on RUR water heaters; It is an option on all others.

Linking Multiple Water Heaters

This is a commercial solution, mostly. Both brands are designed to allow for linking multiple water heaters together with a common manifold and exhaust. This allows a single control to operate more than one water heater to deliver a larger volume of hot water.

Cost Comparison – Navien vs Rinnai

Navien prices are slightly higher when pro installation is considered.

And there is no DIY option, which makes Rinnai a much more affordable choice if you have the capability of installing it yourself.

Navien Tankless Costs
Series BTUs Condensing Installed Cost
NPN-U 160K to 199K No $1,950 – $2,500
NPN-E 120K to 199K No $1,800 – $2,750
NPE-S2 150K to 199K Yes $2,300 – $3,050
NPE-A2 120K to 199K Yes $2,650 – $3,500
Rinnai Tankless Costs
Series BTUs Condensing Installed Cost
V HE 120K to 192K No $1,575 – $2,250
RL HE+ 180K & 199K No $1,700 – $2,600
RLX HE+ 192K No $2,350
RUCS SE 130K & 160K Yes $2,000 – $2,450
RUS SE 130K & 160K Yes $2,125 – $2,500
RU SE 130K to 199K Yes $2,100 – $2,875
RUR SE 160K & 199K Yes $2,700 – $3,200
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Both brands offer a standard 5-year warranty on parts excluding the heat exchanger. However, if a Navien water heater is installed with an external recirculation pump rather than an internal pump using Navien technology, the parts warranty is reduced to 3 years. This setup is called “uncontrolled recirculation” by Navien.


Navien has the better heat exchanger warranty – 15 years on most models. But it drops to just 5 years with uncontrolled circulation. The best advice is that if you want recirculation on a Navien tankless water heater, use Navien parts in order to keep the better warranty in effect.

Rinnai’s heat exchanger warranty is 10 years without exception.

Where Navien is Better Than Rinnai

Warranties: Navien has a better heat exchanger warranty if you use all Navien equipment, which is recommended.

WiFi: And all Navien water heaters have WiFi as standard equipment. You can get it on any Rinnai water heater, but it’s standard on only the top series, RUR.

Energy Efficiency: Finally, top efficiency is higher – 96%  – on the top Navien model compared with 93% for Rinnai. Sure, 3% isn’t much, but as they say, it all adds up if lowering operating costs and carbon emissions are top priorities for you.

Where Rinnai is Better Than Navien

Selection: Whether you want indoor or outdoor installation or a natural gas or propane tankless water heater, Rinnai gives you more options.

DIY: In this category, Rinnai is your only option when comparing Rinnai vs Navien tankless water heaters.


Rinnai and Navien are among the best-selling gas tankless water heaters because they offer quality and reliable performance.

Our final word on the subject is an encouragement to carefully choose an installer. Get written estimates from multiple local, certified and licensed installers. You can use the quick, convenient form on this page for that purpose.

With the estimates, you can also ask for advice about the right size water heater for your home, whether indoor or outdoor installation makes sense and anything else you want information about.

With estimates in hand, check online reviews at Google or the Better Business Bureau.

Choose an installer you believe has the experience and skill to get the job done right the first time.

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