Navien Water Heaters: Review & Buying Tips

A review of the ultra-efficient Navien water heaters from the NPE, NCB, and NHB series utilizing condensing and tankless technology. Explore Navien's top features and excellent energy efficiency, the highest in the water heating industry.

Advantages and benefits of Navien water heaters

Ultra energy efficiency

The greatest benefit of having one of the Navien water heaters is the ultra-high-energy factor, ranging from 0.95 to 0.99. What makes the efficiency superior is condensing technology that uses the flue heat to increase the temperature of cold incoming water in one of the two stainless steel heat exchangers. Such a high efficiency allows Navien to outperform non-condensing tankless water heaters with a larger capacity.

In addition, the primary heat exchanger is also made of stainless steel, and it is the place where the main burner is heating water. The stainless steel ensures durability and longer life, economical and reliable work. Due to the high quality of heat exchangers, Navien provides a long warranty of up to 15 years.


NaviLink is the latest feature available on Navien water heating units and provides Wi-Fi access to water heaters no matter where your location is. Remote access allows easy and convenient control and monitor of the water heating operation. It is available as an add-on feature.


As the heat was "stolen" from the flue gases, its temperature gets reduced, so it exits the vent pipe with a lower temperature than the conventional tankless units, making the venting system economical and easier to install.

All Navien water heaters are designed as indoor-direct and non-direct vents and outdoor models. The indoor type utilizes the concentric and two-pipe system, installed horizontally or vertically, with lengths of up to 100 feet.

Gas burner

The gas burner is eco-friendly as its design allows for the dramatic reduction in CO2 and NOx gases, mainly due to the optimal premixing of the air and gas. These are known as low-NOx gas burners.

No minimum water flow required

Navien water heaters from the "NPE-A" series are designed with the ComfortFlow technology, so no minimum water flow is needed for the activation of the unit. These models are equipped with the recirculation pump and 0.5-gal buffer tank, so the temperature fluctuation or "cold water sandwich" is reduced and the comfort is increased.

Model selection

Navien designs two types of water heaters; gas tankless and combi boilers, all models with high energy efficiency and Energy Star compliance. Navien gas tankless water heaters come from the NPE series and are used either to heat potable water or combined with home space heating. 

Gas combi boilers come from the NCB series and are designed for home space and water heating only in residential applications.

If looking for a hydronic home heater that saves space, money, and time on installation, check out the Navien NHB series.

Navien NPE tankless water heater series

Navien NPE tankless water heaterNavien NPE 240 (photo: amazon)

Navien NPE water heaters are available as standard series NPE-S and advanced NPE-A and can operate as a single unit or in a group with up to 16 units connected through the cascading system.

The main difference between these two series is that the advanced series NPE-A comes with the built-in Intelligent pre-heating function and recirculation system, including an internal pump and buffer tank. This technology that incorporates the above features is known as the ComfortFlow technology, saving time and money to the homeowners while increasing comfort.

Navien NCB-E condensing combi boilers

Navien NCB 210 condensing boilerNavien NCB 210 (photo: amazon)

Navien NCB series is a series of condensing combi boilers designed to heat water and space in larger homes. According to Navien, the NCB-E series can provide enough heat for the whole-house heating and up to three fixtures at the same time.

Combi boilers are available in four sizes with a maximum power of 199.900 BTU\hr. As the above tankless heaters and for an added convenience, NCB-E models are equipped with an advanced control panel.

Navien NHB condensing boilers

Navien NHB 110Navien NHB 110 (photo: amazon)

Navien NHB boilers are designed as the most innovative, condensing, tankless, small, and space-saving products for hydronic space heating in residential and commercial applications. Great features include the advanced burner system, smart built-in controls, high efficiency of 95%, cascading capability, and a long warranty of 15 years.

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