5 Best Condensing Tankless Water Heaters Review

Looking for an energy-efficient water heating solution?

Then, an investment in the best condensing tankless water heater would be a step in the right direction.

Since you’re here, you’ve probably heard about all the wonderful benefits that condensing water heaters bring into our homes and businesses.

In addition to providing us hot water, these appliances have been known to be a more economical way of saving water and heating bills for you.

Sounds impressive, right?

If you’re in the market for a great condensing water heating system, we’ve done the hard yards and short-listet 5 most popular units on the market.

Without further ado, let’s check out our condensing water heater reviews.

A Quick Comparison of Our Favorites

Before you rush out to buy the latest model on the market, it is worth spending few seconds checking out our comparison chart.

Product NameBTUFlow Rate
Takagi T-H3-DV-N199,0001010.75×17.75x 2.5″59
Noritz NRC66-DV-NG15,000 to 120,0006.66.7 x 13.8 x 23.6″39
Rinnai RUR98iN Ultra Series15,200 to 1990009.812.5 x 10 x 26″73
EZ Ultra HE70,0003.427 x 14.5 x 6.5″31
Rheem RTGH-95DVLN11,000 to 199,9009.518.5x 9.75 x 27.5″79

Here are the Best Condensing Tankless Water Heaters

Our team of experts has reviewed more than 70 models to identify those that would be excellent for anyone looking for this type of heating system.

While short-listing, we’ve emphasized on built-quality, energy efficiency, and performance.

1. Rheem RTGH-95DVLN Indoor Direct Vent Tankless Natural Gas Water Heater


Rheem is a well-known and popular North American manufacturer in providing complete heating solutions.

RTGH-95DVLN is an ultra-efficient, state-of-the-art water heater that is perfect for those who are looking for more. This model comes with maximum performance and significant savings of over 40%.

It has a high efficiency of 94%, which leads to big savings over the unit’s life. All thanks to the remarkably powerful stainless steel condensing heat exchanger. Plus, this stainless steel construction protects the main tank from rusting and corrosion for enhanced performance and prolonged lifespan of the unit.

RTGH-95DVLN is an ideal unit for large homes and high demanding families. It also best for hotels, restaurants, and industrial applications. This model comes with high-altitude capability – up to 9,840 ft.

It heats water as high as 185-degree F and provides a continuous supply of hot water efficiently and only when it is needed. You can do the laundry, use multiple showers and dishes without worrying about the hot water supply.

This natural gas-operated unit features highly intelligent electronic controls that help keep safety uppermost while maximizing efficiency.

Notably, RTGH-95DVLN is easily paired with additional units to meet the high demand and provide a system back up to keep your business running if one unit goes down.

You can mount the unit on the wall or to a rack to maximize your valuable floor space. Built-in condensate neutralizer and included service valves keep installation costs to a minimum. It also saves your installation time.

What’s more, this model is compatible with a standard gas line making it easier to replace a conventional tank.

Importantly, it meets or exceeds Ultra-Low NOX (ULN) emissions requirements. So, you can rest assured that it’ll protect the global environment by emitting less carbon dioxide gas.


  • Designed to enhance safety and performance
  • Reliable and Energy star rated
  • Consistent water temperature
  • Self-diagnostic system for easier maintenance and service
  • Efficiency listed by AHRI as a third party
  • Space-saving design
  • Very clear installation instructions


  • Somewhat noisy while running

2. Takagi T-H3-DV-N Condensing High-Efficiency Natural Gas Indoor Tankless Water Heater

Takagi T-H3-DV-N

T-H3-DV-N is a popular and top-selling model of the reputable Takagi water heater brand.

The Takagi T-H3-DV-N delivers on-demand and an endless supply of hot water. The sophisticated features provide water in a steady flow with less fluctuation as long as there is a demand.

It utilizes tankless and condensing technology that make it best for commercial and more demanding applications such as beauty salons and small restaurants. It is also the ideal solution for homeowners looking for a reliable and efficient unit for heavier residential usages.

You can use it for four-bath homes in a warmer climate or three baths home in colder climates. The high GPM rate ensures multiple appliances in your house — sinks, showers, dishwashers, and the like — you can use all at once.

All thanks to its highest power output of 199,000 BTU, the water flow of 10 GPM, and an extra high energy factor of 0.95. Plus this model is certified up to 10,100 ft. altitude.

T-H3-DV-N utilizes commercial-grade, robust, and reliable copper alloy for the heat exchanger tubing. It offers 25 times better heat transfer than stainless steel. It achieves hot water temperature as high as 185-degree F. That’s pretty impressive.

Notably, the exchanger is built to last and itself is guaranteed for 15 years.

With its digital interface, this unit is super to easy-to-use. No need to be a technology whizz to operate this unit! Simply connect it to your gas mains pipe, and it’ll provide hot water to suit your requirements.

Another great aspect of this model is its tankless design with extremely compact size. Plus, the wall-mounted design allows it to occupy less space than any traditional tank-type water heater.

It emits low amounts of NOx. This way, you’ll be able to reduce your carbon footprint.

Takagi T-H3-DV-N is certainly not cheap, but you’ll get what you pay for. It is the product you can rely on.


  • Designed for commercial uses and large homes with multiple baths
  • Easy to set up and use
  • High-flow rate
  • Extremely quiet in operation
  • Ultra-efficient and Energy Star rated
  • Meets or exceeds the ultra-Low NOx regulations
  • Manufactured in Japan


  • It provides less hot water in colder regions.

3. Noritz NRC66-DV-NG Indoor Condensing Direct Tankless Hot Water Heater

Noritz NRC66-DV-NG

Noritz is a well-known brand name in the water heating industry for over 60 years for introducing superior, energy-savings and affordable units.

NRC66-DV-NG is a direct condensing unit, designed for easy use and high performance. Thanks to its innovative heat exchanger technology.

The unit is compact and ultra-lightweight but won’t disappoint you in terms of performance and durability.

It can provide a flow rate of up to 6.5 GPM. It is an excellent choice if you don’t usually consume a lot of hot water at home. It is also beneficial for people who own a small rental/commercial property.

High- efficiency of this unit gives constant hot water. The sophisticated heat exchanger and built-in controller help to monitor the actual temperature to provide consistent and constant temperature, regardless of the flow rate.

It’ll always cut down your energy bill.

NRC66DVNG stands out as one of the most energy-saving units in terms of energy and water use. It can lower your energy bill up to 60% in a year.

The versatility of the NRC66-DV-NG is undeniable. It allows you to use different venting scenarios. Additional adapters and terminations are available to allow for a wide array of venting options. You can vent this unit with 3-inch Schedule 40/80 PVC, CPVS, and PP pipes and fitting.

And the installation is straightforward for most. It is easy to mount absolutely anywhere on your property.

Operating this unit is also effortless. It comes with a 6 ft. power cord and remote control. It runs quietly, so you’re not going to notice while in use.

Finally, this model comes with a 12-year warranty on heat exchanger, 5-year on parts, and 1-year on labor.


  • Modern appearance and compact design
  • Straightforward installation and operation
  • High level of performance
  • Leak-proof build for added durability
  • Different venting options
  • Easy to understand and follow instruction manual
  • Energy Star certified
  • Made in Japan


  • It is designed to be easier to install, but it’s not recommended for inexperienced homeowners.
  • It takes a bit to heat the water.

4. Rinnai RUR98iN Ultra Series Condensing Indoor Natural Gas Tankless Water Heater

Rinnai RUR98iN Ultra Series

If you’re looking for a good-looking, sleek indoor natural gas water heater with high GPM, RUR98iN is a great model to take into consideration.

This model utilizes the latest innovative technology to provide an endless supply of hot water to one or multiple fixtures simultaneously and efficiently.

It can provide a sufficient amount of hot water to homes with up to four bathrooms easily. Thanks to its condensing technology that includes dual heat exchangers to provide maximum efficiency.

This model utilizes recirculation technology with the dedicated recirculation line mode. So you have to wait less for the supply of hot water, and it also wastes less water.

If there is no dedicated recirculation line, no need to be worried! It inaugurates bypass technology and features an internal pump. So, you can use it without a dedicated line. This feature makes the unit perfect for existing household where the recirculation line is difficult to install.

RUR98iN delivers hot water at a consistent and accurate temperature with minimal fluctuation. It provides 9.8 gallons per minute flow rate with power requirements range from 15,200 to 199,000 BTU. The highest energy factor of 0.96 is found on this model.

The state-of-the-art design brings more interaction between this heating system and users. It allows remote and Wi-Fi connection for controlling hot water recirculation.

RUR98iN is a small and compact tankless heater with a dimension of 12.5 x 10 x 26 inches that makes it perfect for wall installation indoor. You can install it almost on any inside wall. All thanks to its direct vent sealed combustion and flexible installation options.

It offers both concentric and dual venting PVC/CPVC options providing flexibility for venting the unit.

Most importantly, its eco-friendly design lets you operate it with reduced water and energy consumption. It also has reduced NOx and CO2 emission and with a lifespan of 20 years. Plus, all the parts used on this unit are replaceable and recyclable.

Although RUR98iN is one of the most expensive models out there, it’ll give you the best user experience and save a large sum of heating costs for you.


  • Fast and consistent on-demand hot water
  • Highest efficiency and water flow rate
  • Versatile venting options
  • Flexible and faster installation
  • Wi-Fi capable plus remote monitoring
  • Environment-friendly design
  • Ultra-low NOx operation


  • The price of this model is relatively high. But you tend to get what you paid for.
  • It requires professional help to install the unit.

5. EZ Ultra HE Natural Gas Indoor Condensing Tankless Water Heater

EZ Ultra HE

The EZ Ultra HE is an indoor natural gas condensing water heater that offers all the features you expect. This model is designed for the typical American home. It is not only affordable but also eliminates a large amount of stand-by energy loss.

EZ Ultra HE is an excellent choice of household with one or two baths. Moreover, the low water pressure ignition makes the unit perfect for users using well water with less powerful or older pumping systems or those who are living at high altitude. This system functions at 8 psi water pressure.

This unit delivers up to 3.4 gallons per minute of continuous and consistent hot water. It uses exhaust gas to preheat the incoming water for enhanced efficiency. Thanks to its condensing Technology.

Conveniently, it features a precise and safe water flow sensor. This fully automatic temperature modulation automatically adjusts the gas supply and exhaust fan rpm once you set your desired outlet temperature. Thus it keeps the temperature constant and stabilizes the exit water flow.

In case the water supply is interrupted, the gas valve automatically shuts off. This model inaugurates Advanced Intelligence (AI) design. That means when you restart the unit, the system automatically works on the temperature settings entered at last use

Aesthetically pleasing and simple design makes this unit easy to install and use.

You can vent the unit horizontally, vertically, or diagonally by using 2-inch Schedule 40 PVC/CPVC. Stainless steel horizontal vent pipe comes included.

You’ll appreciate its fully- automatic operation. It features key touch On/Off switch and water temperature setting with easy to understand advanced technology display.


  • Designed for use in up to a two bath home
  • Well-built and tech support
  • Simple design
  • Automatic flow control for added temperature stability
  • Extremely reliable
  • Easy to install and operate
  • Space and energy saver


  • A minor annoyance is that it does take a few seconds to fire up.
  • Low output – At only 3.4 GPM, this unit has a considerably limited hot water production.


Undoubtedly, these 5 units will benefit you if you’re looking for the most energy-efficient water heating solution. They’ll save you money and conserve energy.

Hopefully, our reviews of the best condensing tankless water heater have made it much easier to narrow down your choices.

The rest is now up to you!

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