Description

Who the Navien NCB-250/150H suits

The NCB-250/150H is the largest model in Navien’s NCB-H combi-boiler line. A combi-boiler is one wall-hung unit that handles both home heating (radiators, baseboard or in-floor heat) and domestic hot water, so it replaces a separate boiler and water heater. Navien rates it for indoor, single-family residential installation. The model number tells you the split: up to 150,000 BTU/h of heating input and up to 210,000 BTU/h for hot water. It suits larger homes with a bigger heating load and a household that runs several hot-water fixtures at once. For hot water, the number to watch is flow at a temperature rise: Navien rates this unit at 5.4 GPM at a 70°F rise, roughly the rise needed in a northern Illinois winter when incoming water is cold. GPM at that rise tells you how many fixtures can run at once, which is why sizing matters. The heating side should be matched to your home’s heat loss, which GSHA reviews during the free estimate.

If your heating load is smaller, the NCB-240/130H or NCB-240/110H may be the better fit. If you need more than 150,000 BTU/h of heating input, look at the fire-tube NFC-250/175H.

Benefits you will notice

• Heat and hot water from one compact unit. The cabinet is 17.3 in. wide, 29.3 in. tall and 12.8 in. deep and hangs on the wall, freeing the floor space a boiler and a tank water heater used to take.
• 95% AFUE, ENERGY STAR certified. AFUE is the heating-efficiency rating; 95% means most of the fuel you pay for becomes heat in your home. As a condensing unit, a second stainless steel heat exchanger captures heat from the exhaust, which is why efficiency is high and why the unit vents in PVC and needs a condensate drain.
• Hot water on demand: up to 10.8 GPM, 5.4 GPM at a 70°F rise. Navien rates the NCB-250/150H at 10.8 GPM at a 35°F rise, 7.6 GPM at 50°F and 5.4 GPM at 70°F, with a minimum flow of 0.5 GPM so even a low-flow faucet gets hot water. The 70°F figure is the one to plan around in winter.
• 15:1 hot-water and up to 11:1 heating turndown. Turndown is how low the burner can modulate; a high ratio means the boiler can idle at 14,000 BTU/h on mild days instead of short cycling, which is easier on the unit and steadier for comfort.
• Zoning built in. The control board has powered connections for three zone pumps or three zone valves, so many two- or three-zone systems (upstairs/downstairs, or radiant plus baseboard) can be wired directly to the boiler.
• Optional Wi-Fi and recirculation. NaviLink ($288.43) or NaviLink Lite ($153.55) adds remote control from your phone. If you have no dedicated return line, the NaviCirc valve ($99.60, external pump not included) recirculates through existing pipes to shorten the wait for hot water at distant fixtures. These are GSHA’s current add-on prices; we confirm any installation cost for accessories with your estimate.

Price and installation estimate

Installed package price: $10,730.70. This is a complete installed package, not an equipment-only price. GSHA’s standard combi-boiler installation includes setting and leveling the unit; water piping modifications; gas line modification with a new gas valve; a new condensate drain line; a new 150 lb pressure relief valve; a 4.8-gallon hydronic expansion tank and a domestic hot-water thermal expansion tank; the Navien primary manifold kit; a NaviClean magnetic filter; a commissioning kit (Protector F1 and Cleaner F3); new PVC flue venting; removal and disposal of the old equipment; and start-up, testing and a safety inspection.

Your final quote can change with gas line capacity and length, the venting route and length, the condensate drain location, water quality treatment, electrical work, zoning and piping changes, permits, accessories such as NaviLink or NaviCirc, and how accessible the boiler location is. The estimate is free. Financing available with approved credit; see financing options.

Request an Installation Estimate or call (224) 220-3660.

Navien NCB-250/150H specifications

Sound level is not published by Navien for this model; see Navien product data for anything not listed here.

Installation and warranty

GSHA Services, LTD is a Navien Service Specialist (NSS), approved June 30, 2026, and an authorized Navien dealer, listed on Navien’s installer locator at navieninc.com, with Navien Level 3 trained technicians. Every NCB-250/150H is installed to the standard scope listed above and commissioned with a start-up, test and safety inspection. We serve McHenry County and Lake County, IL, and the surrounding Chicago suburbs and southeastern Wisconsin; see our service area.

Navien limited warranty (residential): 1 year on labor, 5 years on parts and 10 years on the heat exchanger. Navien’s NCB-H warranty applies to single-family residential installations only, and coverage runs from the installation date, so the homeowner or installer must provide proof of the installation date to Navien (otherwise Navien uses six months after the manufacture date). Navien voids the warranty for units bought through internet or e-commerce channels, improper installation, lack of maintenance or hard-water damage.

GSHA Install-Right coverage: GSHA’s combi-boiler installation package adds 5-year parts and 5-year labor coverage from GSHA. The labor coverage is valid only with annual GSHA maintenance, and service by others voids GSHA’s labor coverage. For warranty service, contact GSHA as the original installer. GSHA’s coverage is separate from Navien’s limited warranty.

Frequently asked questions

How much does a Navien NCB-250/150H cost installed?

GSHA’s installed package price for the NCB-250/150H is $10,730.70, which includes the standard combi-boiler installation listed above. Gas line, venting, condensate, electrical, zoning and permit conditions at your home can change the final quote, and the estimate is free.

Is the NCB-250/150H big enough for my home?

Only your home’s heat loss and a count of the hot-water fixtures you run at once can confirm that, which GSHA reviews during the free estimate. As the largest NCB-H model (150,000 BTU/h heating input, 5.4 GPM at a 70°F rise) it suits larger homes; smaller homes are often better matched to the NCB-240/130H or NCB-240/110H.

What is the difference between the NCB-250/150H and the NCB-240/130H?

The NCB-250/150H has more heating input (150,000 vs 130,000 BTU/h), more hot-water input (210,000 vs 199,900 BTU/h) and slightly more hot-water flow (5.4 vs 5.1 GPM at a 70°F rise). Both are 95% AFUE, ENERGY STAR certified and use the same 17.3 x 29.3 x 12.8 in. wall-hung cabinet.

Does the NCB-250/150H work with propane?

Yes. Navien’s NCB-H gas system is field convertible between natural gas and propane, and the conversion kit is included with the unit. Tell us your fuel when you request an estimate so the installation is quoted correctly.

What venting does a condensing combi-boiler need?

The NCB-250/150H is a direct-vent unit that uses 2 in. PVC up to 65 ft or 3 in. up to 150 ft. Because it condenses exhaust moisture to capture extra heat, it also needs a condensate drain line, which GSHA’s standard installation includes.

What maintenance keeps the warranty valid?

Navien requires the unit to be installed by a licensed contractor and maintained per its manual, and GSHA’s 5-year labor coverage requires annual GSHA maintenance. Ask us what the annual maintenance visit includes when you request your estimate.

Request your Navien NCB-250/150H estimate

Ready to replace a boiler and water heater with one efficient unit? Request an Installation Estimate online or call GSHA Services, LTD at (224) 220-3660. Compare all sizes on our Navien boilers and combi-boilers page, or learn more about boiler installation and water heater services from GSHA.