Navien NCB-250/150H - Condensing Combi-Boiler - 250,000 BTU DHW / 210,000 BTU HTG

The Navien NCB-250/150H is a 95% AFUE condensing combi-boiler that combines powerful space heating and on-demand domestic hot water in a single wall-hung unit. With a maximum input of 150,000 BTU/hr and a net AHRI rating of 120,000 BTU/hr, this unit delivers efficient performance for larger residential applications. It offers a 11.1:1 turndown ratio for heating and a 15:1 ratio for hot water, providing responsive modulation based on system demand.

The NCB-250/150H is field convertible from natural gas to propane and supports a range of venting materials including PVC, CPVC, polypropylene, and stainless steel. It also features compatibility with Navien’s NaviLink smart home controller for remote access and monitoring.

Features:

95% AFUE high-efficiency rating
150,000 BTU/hr heating input
120,000 BTU/hr net AHRI rating
11.1:1 turndown ratio for space heating
15:1 turndown ratio for domestic hot water
Field convertible between natural gas and propane
Smart controls with NaviLink compatibility
Energy Star certified
Compact wall-mounted design
Compatible with 2" or 3" venting (PVC, CPVC, polypropylene, stainless steel)

Applications:

Whole-home space heating and domestic hot water
Medium to large residential homes
Indoor installations with venting flexibility
Natural gas or propane systems
Retrofits and new construction
Smart home integration with NaviLink controller

Aim high with Navien...

High efficiency, High output, High performance, all in one compact combi

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
Highest number of built-in zone controls for valves or pumps... up to three
Highest full lineup 2" PVC venting lengths... up to 65 feet
Highest number of cascade capable units with NPE tankless water heaters... up to 15
High altitude certification... up to 10,100 feet (NG or LP)
Lowest minimum fire BTU for residential combi-boilers... as low as 10,700

New Navien NCB-H...the complete combi package and no comprimises

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.

Navien NCB-H Full House

COMPARE these advantages and see why NCB-H combis are the right fit for small and large homes

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.

Separate stainless steel flat plate
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 System
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.

Low noise levels

Installations in or near media rooms, recreation rooms or any living areas of the house are possible with the quiet running NCB-H combi-boilers.

Gas Flow Control System
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.

Dual Stainless Steel

Heat Exchanger

Designed for exceptional

heating performance and longevity

Heating up to

150,000

BTUs per hour

Built-in DHW module now with
higher performance
Navien’s NCB-H generates enough hot water to run up to 3 showers and a dishwasher at the same time.

NCB-H Module

DHW up to 210,000 BTUs per hour

Expanded DHW Capability

For increased domestic hot water flow demand, the NCB-H can be cascaded and common vented with up to 15 NPE tankless water heaters

Cascading DHW Capabilities

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Collection: NCB

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NCB-250/150H - Condensing Combi-Boiler - 250,000 BTU DHW / 210,000 BTU HTG