Navien Inc., the leader in condensing technology in the wall-hung tankless water heater, combi-boiler and boiler markets, introduced its first non-condensing tankless water heater models, at a gala event for about 100 contractors, reps, distributors and staff at its Irvine, California headquarters last month. 

Shortly after the Oct. 9th event, Navien began shipping its Navien Premium Non-Condensing tankless (NPN) water heater series, available in two models and six sizes:

• The NPN-U (Universal), which can be installed either indoors or outdoors with an optional vent cap kit.

• The NPN-E (Exterior) is a dedicated outdoor unit that features remote control and built-in button controls for easy service.

Both units will be available in 160,000 BTU/hour, 180,000 BTU/hour and 199,900 BTU/hour models for either natural gas or liquid propane. Optional pipe covers fit under both the NPN-U and NPN-E models for added protection and a cleaner look. The compact units are only 14 inches wide to fit into a standard stud space, plus, the outdoor model can be installed using an optional recess box.

Recognizable tech

Although this is Navien’s first entry into the non-condensing market, many contractor customers who have installed its popular NPE-A and NPE-S condensing line are bound to recognize many of the same features and benefits.

“A lot of the technology we’ve built into the new non-condensing units comes from our condensing history,” says Dave Hoskyn, Navien’s national training manager.

One of those biggest similarities is the use of a stainless steel heat exchanger.

“That’s a big deal for us,” Hoskyn adds. “The heart of everything we do is the stainless steel heat exchanger, and this is the first non-condensing model to come with it.”

Both units come not only with a stainless steel heat exchanger, but a patent pending stainless steel burner specially made for the non-condensing units with the same very low NOx level as the NPE.

“We all know that stainless is a more durable product,” Hoskyn adds. “Stainless steel provides the heat transfer that’s needed along with durability and longevity.”

Plus, the patented NaviTech exchangers and burners, like about 90 percent of everything else inside the non-condensing models, are made by Navien directly at its South Korean manufacturing facility.

“We are well-known for making our own stainless steel components,” Hoskyn adds, “whether it’s for a boiler, water heater or combi-unit. It’s all ours.”

In addition, both the NPN-U and NPN-E have recirculation controls built into their circuit boards, another industry first for non-condensing tankless water heaters. Although the units don’t come with built-in circulators, Hoskyn says all contractors need to do is add a pump, which can be powered by the PCB. A dipswitch change enables the recirculation with multiple parameters and control options to customize the system.

Built-in water adjustment and mixing valves control the water through the units in order to maintain set point.

“The water adjustment valve (WAV) and mixing valves in conjunction with the burner technology will give the units very stable water temperatures,” Hoskyn explains.

An air pressure sensor (APS) also helps the non-condensing units maintain proper combustion.

“Instead of just being an on or off switch,” Hoskyn adds, “the APS monitors the pressure differential between the exhaust and the intake.”

This helps maintain the air/gas ratio in high-wind situations and maintains water-heating capacity with a restricted vent.

“And that will help us maintain a clean burn,” Hoskyn explains. “Instead of just shutting the unit down, the APS allows the unit to compensate.”

Of course, the APS also safely disables the units in cases of vent blockages.

Contractors will also recognize the integrated control panel found on the NPN-Universal, which allows for the same easy adjustment of water temperature, operation status and troubleshooting found on the NPE. The NPN-E control panel has the same control system as the NPN-U, just with the panel positioned inside the water heater case.

The NPN-U units feature a concentric venting system, with exhaust on the inside and intake on the outside. Up to two units can be cascaded with a simple cable with additional venting options available for other configurations.

Finally, an optional Navilink Wi-Fi remote control can be used for both the universal and the exterior models to control temperatures remotely, access usages data and receive diagnostic notification from a smart phone or tablet.