Navien NCB-250/150H Condensing Combi Boiler

Sale price€789,98 Regular price€1.579,95
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3.7

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 5.1 cm or 7.6 cm 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 @ 21.1 °C 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 5.1 cm PVC venting lengths... up to 1981.2 cm
  • Highest number of cascade capable units with NPE tankless water heaters... up to 15
  • High altitude certification... up to 10,3048 cm (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.

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.


Up to 5.4 GPM @ 21.1 °C 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.


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.


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 t
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Fast, tracked shipping

Most orders ship within 1-3 business days.

Secure checkout

All major cards accepted, protected checkout.

Warranty on every purchase

New and factory-reconditioned items are covered. See product details for warranty length.

Customer reviews

3.7 (3 reviews)
Write a review

Does the job, nothing special

It works fine for basic needs, nothing extraordinary but nothing terrible either. The listed spec spec sounds great on paper but real-world performance is only average.

Mark J.· July 19, 2026 Verified purchase

Fine for basic use

A solid middle-of-the-road option if you're not looking for premium features. Customer support was slow to respond when we had a question about the warranty. Not perfect but reasonable for the price point.

Keith L.· January 28, 2026 Verified purchase

Solid boiler, would buy again

My old boiler finally gave up, so I replaced it with this one and the difference is night and day. It looks great in our kitchen and several guests have asked where we got it. Happy with the purchase overall and would buy again.

Megan U.· August 1, 2025 Verified purchase

Fast, tracked shipping

Most orders ship within 1-3 business days.

Expert support

Questions about parts, fit, or warranty? We're here to help.

Warranty included

New and reconditioned items are covered by manufacturer warranty.

Secure checkout

All major cards and secure payment methods accepted.