8 Best Non-Condensing Tankless Water Heater Reviews (UBER Buying Guide)

If you’re confused about which type of tankless water heater makes the best fit for your home, you’ve first got a broad choice to make between condensing and non-condensing models.

What’s the difference, then?

Well, non-condensing units are normally cheaper off the bat and also require almost no maintenance. They’re also compact and space-saving.

The trade-off is reduced energy-efficiency, but why is this?

In a condensing heater, the exhaust gases are harnessed to provide additional heat, something you won’t get with vented non-condensing models.

Given that you’ll already be making significant savings on your energy bills simply by installing any tankless water heater, perhaps you’ve decided a non-condensing model is appropriate even if it’s slightly less energy-efficient.

If so, we’ll fire directly into our capsule reviews right now to simplify your buying decision. If not, we’d refer you to our selection of the best condensing water heaters.

1) Rinnai V65EN Outdoor Tankless Natural Gas Water Heater

If you’re looking for a simple but effective natural gas water heater that eliminates the need and cost of storing water in a tank, the Rinnai V65EN hits the spot.

Flow rate depends on the outside temperature so expect anywhere from 4 to 6 GPM in colder climates and up to 6.6 GPM where it’s warmer. Power output is 150,000 BTU per hour.

Weighing less than 50 pounds and measuring up at 13.8 x 6.8 x 20.9 inches, this potent unit can be mounted outside with ease. Installation is straightforward and you won’t need anything much by the way of ongoing maintenance.

For smaller homes with less demanding hot water requirements, the V65EN is a pared-down gem.


  • Compact whole-house unit you can mount outdoors
  • Easy to install and maintain so cost-effective
  • Robust 6.6 GPM flow rate ideal for 1 or 2 bathrooms


  • You’ll need to buy remote separately
  • Insufficient power for a larger home

2) Rinnai V65IN Indoor Tankless Natural Gas Water Heater

An indoor tankless non-condensing heater from Rinnai, the V65IN uses ultra-low NOx technology and natural gas.

Rugged and built to last, this heater is packed with safety features including isolation valves, a pressure relief valve and leak detection to complement those limited emissions.

This unit works well in smaller homes and is safe to use in mobile homes.

Flow rate maxes out at 6.6 Gallons Per Minute. Temperature is preset to 120 Fahrenheit degrees.

The V65IN might not come packed with bells and whistles but it gives you hot water on demand in a neat, space-saving appliance you can mount indoors with relative ease.


  • Certified to California and Texas emissions standards for NOx
  • ENERGY STAR rating of 0.82 so efficient in operation
  • Safety features uppermost and dependable, lengthy warranty


  • Controllers are optional extras so budget for these

3) Rinnai V75IN Indoor Tankless Natural Gas Water Heater

Stepping things up in Rinnai’s enduringly popular Value Series, the V75IN can deliver a maximum flow rate of 7.5 Gallons Per Minute. This is enough for medium-sized properties and the unit also serves well in manufactured homes.

Meeting all requirements for low nitrogen oxide emissions and laden with safety features like all Rinnai heaters, you can fire up the gas without any niggling concerns.

You won’t get a complex interface or scores of settings but this simplicity is a key selling point for Rinnai heaters rather than a drawback.

For a set-and-forget solution providing hot water on demand at a vigorous flow rate, the V75IN combines performance and value in one winning package.


  • Flow rate adequate for mid-sized homes
  • Advanced leak detection system onboard
  • Ultra-low NOx emissions ramping up safety further


  • Doesn’t work well in larger homes or for multiple demanding applications

4) Rinnai RL75IN Large Tankless Natural Gas Water Heater

The RL75IN is another natural gas tankless water heater capable of generating 7.5 GPM at the upper end.

The space gray finish means this sleek unit won’t destroy the aesthetics of your room and its slimline size allows you to install it practically anywhere. Installation is not tough and you can take care of venting equally easily.

Unlike other Rinnai models where the remote costs extra, the digital controller streamlines your temperature tweaking and comes bundled free of charge.

Ideal for homes with up to 3 bathrooms, the only real limitation beyond the size of your house is that you need to be reasonable about your hot water demands. Running more than 3 applications at the same time will impact performance.

While the RL75IN is not cheap, you’ll get a striking and effective non-condensing water heater from a stellar brand.


  • Digital controller comes included with this model
  • Space-saving so mount anywhere and vent easily straight outside
  • Thermal efficiency rating of 82% and ENERGY STAR certified


  • Limited to 2 or 3 simultaneous applications before performance dips

5) Rinnai RL94EN Outdoor Tankless Natural Gas Water Heater

A large unit for outdoor mounting, this tankless natural gas water heater will serve bigger homes and can yield dramatic energy savings over the course of a year.

Maximum water temperature is 140 Fahrenheit degrees in a residential setting and the flow rate of up to 9.4 GPM provides enough water for multiple baths and showers at the same time.

A sensor in place accompanied by an indicator alerts you when the Rinnai needs back-flushing. This needs doing on roughly an annual basis. Beyond this, you’ll have precious little maintenance to worry about.

A powerful non-condensing water heater giving you hot water on demand throughout your larger home, the energy-efficient RL94EN is well worth popping on your shortlist.


  • Ideally suited for larger homes thanks to outstanding flow rate
  • WiFi-enabled so slots neatly into a smart home
  • Highly effective even when water pressure is low


  • Overkill in a smaller home or apartment
  • Water in the pipes is not heated

6) Rinnai RL75EP Medium Tankless Propane Water Heater

A mid-sized unit to complete our curation of Rinnai non-condensing heaters, the tankless RL75EP runs on propane.

Part of Rinnai’s Luxury Series, this model consistently garners outstanding reviews and generates very little negative kickback.

7.5 GPM maximum flow rate will ensure you’ve got enough hot water on tap in a smaller home. You’ll be fine running 3 applications but if you frequently place heavier burden on your heater than this, you should invest in a beefier model.

This tankless heater is by no means cheap, but if you have a more fluid budget and exacting standards, you won’t sorry you made the investment. Expect years of faithful, hassle-free service and lowered energy bills as your ROI.


  • For homes with 1 or 2 bathrooms requiring multiple simultaneous applications
  • Fits easily on any outside wall so free up space indoors
  • WiFi monitoring baked in for increased convenience


  • You’ll need to dig deeper for this model

7) Takagi T-KJr2-IN-NG Indoor Tankless Natural Gas Water Heater

Japanese firm Takagi has a strong line of non-condensing tankless water heaters. The clumsily-named T-KJr2-IN-NG runs on natural gas and comes in at a very keen price-point.

Although inexpensive, you should be aware front and center that installation costs could easily run you the same as the sticker price so make provision and budget for this before committing to purchase.

Maximum flow rate of 6.6 Gallons Per Minute should be enough for smaller homes but you’ll run into problems if you constantly place heavy demand on your water.

The smallest model in the line-up, this unit is tailor-made for apartments or small homes with relatively light water usage. If that fits the bill, you’ll get a rock-solid water heater built to last. You can find this same water heater in an outdoor variant along with the same model but running on propane.


  • Perfect for small homes with lower flow-rate requirements
  • Consistent temperature at all times
  • Air Fuel Ratio sensor keeps emissions and pollutants to an absolute minimum


  • Installation can be costly

8) Takagi T-K4-IN-NG Indoor Tankless Natural Gas Water Heater

Ratcheting up in terms of price and capacity, the T-K4-IN-NG is suitable for indoor installation only. There is an optional direct-vent conversion available.

With an impressive 8 GPM flow rate, you’ll get more than enough water for the whole family in a medium-sized home even if you’re all showering at the same time.

The intelligent self-diagnostics keep this efficient non-condensing unit running like a dream with very little user input required.

Since ambient temperature outside doesn’t impact water temperature, you’ll enjoy wonderfully regular hot water just the way you like it.

If you want to take control remotely, you’ll need to buy the controller separately.


  • Smooth hot water supply not affected by the climate so perfect for northern states
  • Comprehensive self-diagnostic system in place
  • Remote control gives you improved temperature refinement


  • Remote does not come included, a common minor bugbear rather than a deal-breaker


While we normally boil down our findings to a single winner, today we’re choosing two since it’s unfair to compare a smaller unit with something designed for a much larger property.

If you live in a compact house or an apartment, the Takagi T-KJr2-IN-NG is a smart choice. If you can weather the installation costs or DIY it, you’ll get outstanding value combined with absolute consistency, great flow rate and minimal emissions.

If you’ve got a larger home with more challenging hot water demands, we’d recommend the WiFi-enabled Rinnai RL94EN. With class-leading flow rate and an ability to surge on even with limited water pressure, this is out standout favorite for bigger properties.

Come back soon and bookmark our site, designed to give you a frank and honest breakdown of all the water-related products you could possibly need for your home.

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