NCB-H offers industry leading DHW features including the highest maximum BTU/h for DHW (210,000), highest flow rate of 5.4 GPM at 70° rise and a DHW turndown ratio of 15:1.
Navien is the #1 manufacturer of
combi-boilers in North America*
*According to BRG
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Highest DHW maximum BTU’s in residential combi-boilers...
up to 210,000 per hour
Highest DHW flow rate @ 70°F rise...
up to 5.4 GPM
Highest number of BTU sizes for
the North American residential
combi-boiler market
Highest residential combi DHW TDR...
15:1 for all models
Highest residential combi heating
TDR... up to 11:1
Built-in zone controls for up to three zone valves or zone pumps
Cascade capable with up to 15 NPE tankless water heaters for expanded DHW flow
Lowest minimum fire BTU for residential combi-boilers... as low as 10,700
Navien's innovation and technological advancements have done it again. The new NCB-H is taking combi performance to the highest levels. As the competition tries to get closer, Navien ingenuity keeps advancing their lead.
Dual stainless steel heat exchangers for heating
Durable stainless steel heat exchangers resist corrosion, resulting in longer life and improved heat recovery from flue gases for superior efficiency.
Up to 5.4 GPM @ 70°F temperature rise for DHW
Separate stainless steel flat plate heat exchanger for DHW creates the lightest flow rates for any combi-boiler in the industry.
Dual Venturi and field gas convertibility
Dual Venturi system creates better combustion control and turndown ratio. Orifice conversion kit for easy field gas convertibility from NG to LP is included with every NCB-H Series combi-boiler.
Easy access to DHW module
and valves
All components of DHW module including water feed valve, flow adjustment valve, mixing valve and 3-way valve are right behind circuit board for easy serviceability.
TDR 15:1 for DHW and up to 11:1 for heating
The sophisticated gas flow control system provides a high turndown ratio, reducing energy waste and excessive boiler cycling and enhances temperature control for DHW.
Designed for exeptional heating performance and longevity
Heating up to
150,000
BTUs per hour
Navien’s NCB-H generates enough hot water to run up to 3 showers and a dishwasher at the same time.
Separate DHW stainless steel flat plate heat exchanger
Navien’s new innovative domestic hot water heat exchanger now generates even more hot water, giving customers the ability to run up to 3 showers and a dishwasher, all at the same time.
Integrated boiler pump for space heating and DHW. No need for an external boiler pump saving installation time, space and costs.
DHW SS flat plate heat exchanger 5.4 GPM @ 70°F temperature rise. One of the highest flow rates in the industry.
New mixing valve.
New easy access 3-way valve.
New flow adjustment valve.
Water feed valve.
At the push of a button, the Navien HotButton hot water system activates the internal recirculation pump and gas fired burner to heat water in the supply lines to provide hot water whenever it’s needed.
At the push of a button, the Navien HotButton hot water system activates the internal recirculation pump and gas fired burner to heat water in the supply lines to provide hot water whenever it’s needed.