Home Heating Heroes

Some of the links below are affiliate links, meaning, at no additional cost to you, we earn a commission if you click through and purchase. Learn more

Your Guide to Home Heating and Cooling Systems

Best Rinnai Tankless Water Heaters - 2022 Buying Guide

Last Updated on February 10, 2022

I love having a tankless water heater for my home office. It’s great not having to worry about the big water tank taking up my valuable space and just being able to jump in the shower at any time I want. While I don’t own a Rinnai, if I had a larger place I’d absolutely have bought one. 

Every brand in every kind of product has some kind of specialty. Rinnai’s specialty is having the highest overall performance of any brand. Pound for pound an equivalent model from some other brand will lose to a Rinnai whether it be a high-end Rinna vs a high-end something else, or low end vs low end (or in some case, a middle of the road Rinnai vs a high end some other brand).

The only real issue is the price point for Rinnai brand tankless water heaters is usually WAY higher than other brands…and that actually often means you’re paying way too much for the performance at certain ranges.

So today I’m going to pull out what I feel are the best Rinnai models that price themselves fairly; if another brand does about the same job but cheaper I’m leaving it off, going only for the best of the best here.

A Quick Overview Of Terms

I use a few uncommon abbreviations and terms in this article, which I’ll quickly explain here:


British Thermal Unit (per hour), the amount of heat required to heat one pound of water one degree. The higher this number, the hotter your tankless water heater.


Gallons per minute. In this context, how many gallons per minute a tankless water heater can effectively heat without starting to output cold bursts. Bigger is better, once again.


A condensing heater keeps the propane or natural gas more highly compressed, resulting in a more efficient heat output that isn’t as affected by the weather. Non-condensing units (the majority) lack this feature and may perform up to 50% less efficiently in cold






Best Choice

Rinnai RUR98iP 9.8 Max GPM

Price on Amazon


  • Amazing in warmer climates for huge homes

  • Energy efficient condensing gas

  • Wi-Fi controlled


  • Efficient at producing hot water

  • Weighs roughly 82 lbs

  • Able to achieve a respectable 5.5 GPM


Rinnai V65EP 6.5 GPM

Price on Amazon


  • Good, cheap tankless water heater for your average sized home

  • Perfect for the average two-bathroom home

  • Certified for use in manufactured or mobile homes


  • Above average 150k BTuH with a decidedly average 6.6 GPM

  • 82% efficient non-condensing propane unit

  • Low NOx emissions


Rinnai RL75IN

Price on Amazon


  • Excellent for warm climates

  • Naturally good efficiency (82%)

  • Wi-Fi capable


  • 180k BTuH and 7.5 GPM under fairly low temperature rises

  • 5 year warranty on parts and heat exchanger

  • Usefulness up to 10, 200 feet


Rinnai C199EN

Price on Amazon


  • 9.8 GPM at a relatively low heat rise

  • Perfect all weather tankless water heater

  • Runs on either propane or natural gas


  • High (96%) efficiency

  • 199k BTuH

  • Energy Star certified


Rinnai RUC98iN

Price on Amazon


  • 9.8 max GPM that falls to 7.7 GPM at a 50-degree rise

  • Efficient heating

  • Ideal for a very large house or medium sized business


  • 199k BTuH

  • 96% energy efficient

5 Best Rinnai Tankless Water Heater Reviews

1.  Rinnai RUR98iP 9.8 Max GPM Propane Tankless Water Heater

Top of the line for large residential or light commercial tankless water heaters.

The Rinnai RUR98 (iN or iP; they’re interchangeable save that the former uses natural gas and the latter propane) is not just the best that Rinnai offers, I’m hard pressed to find any tankless water heater of ANY brand that outperforms it in even one category of use.

199k BtUH translates into a maximum of 9.8 GPM at a fairly low rise in temperature (about 30 degrees), making it amazing in warmer climates for huge homes or a medium sized business.

Its energy efficient condensing gas or propane heater also make it perform admirably in colder climates, still being able to achieve a respectable 5.5 GPM if it needs to raise the temperature a whopping 70 degrees, and an above average 7.7 GPM with a still quite hefty 50 degree rise.

This is hard to beat in any climate, warm or cold as a result, and works for altitudes up to 10, 200 feet above sea level.

On top of the raw performance, the RUR98 comes with a few quality of life features like Wi-Fi connection to make turning it simple and easy when the need arises.

The HUGE need here is recirculation.

Most homes lack a dedicated return line for water: it all flows in, then flows directly out through drains. Return lines can be installed to essentially allow for more efficiency in hot water. It gets pumped back into circulation instead of just floating out the drain and all that hot water being lost.

The main issue is return lines are EXPENSIVE. This unit gets around that by having an (optional) feature to turn your cold water line into return line at certain times of the day or with the flip of a switch. This basically just makes it even MORE efficient at producing hot water since 90% of it isn’t just lost after bouncing off your body for a fraction of a second.

The only real downsides (as with ALL Rinnai tankless water heaters) are bulk and price. It’s the size of a suitcase and weighs roughly 82 lbs, and has a similarly hefty price tag: a bit over $2000.

Still, you can’t say they’re particularly gouging you, that’s simply the fair price for such high performance metrics. It’s a bit overkill for many homes, but when you need that kind of raw power and don’t want to sacrifice comfort and ease of use, Rinnai has you covered.

2.  Rinnai V65EP 6.5 GPM Outdoor Tankless Propane Water Heater

If you need a cheaper option for more compact homes, this has you covered.

The performance here is nothing in particular to write home about. Don’t get me wrong, it’s not BAD by any means, but isn’t the “cut above” that most Rinnai units are.

This has a slightly above average 150k BTuH with a decidedly average 6.6 GPM, making it perfect for the average two-bathroom home. It is an 82% efficient non-condensing propane unit (it also comes in natural gas if necessary), which actually makes it a little bit more efficient than many non-condensing units (by a percent or two).

The primary draw here is that it’s certified for use in manufactured or mobile homes, which is actually a rarity among tankless water heaters. This makes it both a solid option in its own right, and one of the ONLY options for someone in a mobile home to use.

The low NOx emissions are icing on the cake, and for the price (around $700) it’s hard to go wrong here. This is sort of a “man among titans” in terms of performance. By the standards of most other companies this would be average rather than close to the lowest end.

I highly recommend it if you want a good, cheap tankless water heater for your average-sized home and don’t need the huge overkill capacity of many of the rest on this list.

Similar model you may prefer Rinnai V65iN .

3. Rinnai RL75IN Tankless Water Heater

This one boasts 180k BTuH and 7.5 GPM under fairly low temperature rises (30 to 35 degrees). At 50 degrees this falls to 6 GPM (which isn’t so bad) and at a 70 degree rise it’s a measly 4.3 GPM.

This makes it an excellent tankless water heater for warm climates, and remains quite good for places with somewhat chilly groundwater, but unfortunately abysmal for truly cold climates.

This is due mostly to this being a non-condensing propane or natural gas unit. It has a naturally good efficiency (82%), but this efficiency falls precipitously (often up to 50%) in colder weather, resulting in an almost exponential drop in usefulness the colder the incoming water is.

Still, this is a Rinnai and has everything else you’d expect from one, with the Wi-Fi controls, usefulness up to 10, 200 feet above sea level, and limited warranty (5 year on parts and heat exchanger, 2 years on labor; standard for residential units).

It’s by no means bad, and quite good for warm and semi-warm climates (places where the groundwater is cooler than 70 degrees for whatever reason but isn’t 40 or below, which is most places), but doesn’t have the same oomph as other Rinnai models that lets it be used anywhere for almost any purpose.

The nearly $1200 price tag doesn’t help matters, as it becomes potentially tempting to either downgrade slightly on performance to get the V65 or up the price by only $300 to get our much better penultimate model.

Read the full review of Rinnai RL75iN.

4. Rinnai C199EN Commercial Tankless Water Heater

A beast of a machine.

The Rinnai C199E series models are close to the most powerful and versatile tankless water heaters you can buy.

In terms of raw power, they have that in spades, with a 9.8 GPM at a relatively low heat rise, while still maintaining a respectable 5.5 GPM at a 70 degree rise in temperature. This makes it a perfect all weather tankless water heater, maintaining most of its high (96%) efficiency even with the coldest possible groundwater, putting that 199k BTuH to good use.

In terms of versatility it can be used in nearly every way imaginable, having install options ranging from a simple single unit, to installing it as part of a chain of up to 25 of the same unit (linked together to a single controller), or even having it be used as a “hybrid” with a standard tank water heater, the latter being a backup for unexpectedly high demand.

It can run on either propane or natural gas depending on what’s available (the EP is propane, the EN is natural gas), and in either case it is an energy efficient condensing heater. Like almost all Rinnai models it is also Energy Star certified and Wi-Fi capable for remote control via computer or even phone.

If you need a commercial tankless water heater, particularly one that can be scaled up with your business, this is the top of the line. It’s a little pricy (near $2000) but its quality is top notch and its warranty (6 year on the heat exchanger, 5 year on parts, and 2 years on labor) takes a lot of the sting out of that price tag.

This doesn’t make it to the very top of the list because it’s beyond overkill for most people, and others perform as well or better for residential use, but in terms of raw performance this is the best on the market.


5. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater

So close to our top model, and yet not quite.

This one has many of the same stats as our top model. 199k BTuH, 9.8 max GPM that falls to 7.7 GPM at a 50-degree rise, and 5.9 GPM at 70 degrees, 96% energy efficient condensing natural gas or propane, the works.

The main thing it lacks is the recirculation system. Now, before I continue, I do want to say that being close to $500 cheaper than our winner, this is a much better option for anyone that doesn’t need the recirculation system, hands down.

HOWEVER, the recirculation is a big deal if you have a very large house or medium sized business and want the most efficient heating you can possibly get. It cannot be overstated how big of a deal the recirculation system is in regards to saving water and keeping the hot water flowing through heavy use at multiple use points throughout a building.

Lacking that inherently makes it a much less efficient system. But it IS overkill in a lot of cases, so this takes rather than second place, more first place with a caveat: it’s only better if you don’t need that extra bit of heat efficiency.

Read the full review of Rinnai RUC98iN.

Final Verdict


While the RUR98iN is the winner by a simple fact of being the most versatile, powerful, and widely usable Rinnai tankless water heater, it was a close race.

Every tankless water heater on here is the best for somebody in some situation, with the possible exception of the RL75. Of particular note is the RUC98iN Ultra which lacks only one feature (albeit an important one) over the RUR98 and comes in significantly less expensive.

I can’t stress enough that if the recirculation system is not NECESSARY to you, the RUC98 is a far better deal, but simply having the option makes the RUR98 much, much better in the circumstance that you actually do need that extra efficiency.

Homeheatingheroes.com is a participant in the Amazon Services LLC Affiliate Program, an affiliate program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.