Description

Who the Navien NHB-55H is for

The Navien NHB-55H is a heating-only condensing boiler. It heats the water that runs through your radiators, baseboard or radiant floor loops; it does not make domestic hot water on its own. If you also want hot water from the same unit, look at a Navien combi-boiler instead, or pair the NHB-55H with an indirect tank. With an 8,000–55,000 BTU/h heating input, it is the right size for homes with a smaller heating load: a compact house, a condo or townhome, or a single addition or zone. Because the burner can run as low as 8,000 BTU/h, it can keep up with mild-weather demand without constantly stopping and starting. A heat-loss calculation at your estimate confirms whether the NHB-55H fits your home in a northern Illinois winter, or whether a larger NHB-H model is the better match.

What you get with the NHB-55H

• 95% AFUE, ENERGY STAR certified. AFUE is the heating-efficiency rating; 95.0% means very little of the gas you pay for goes up the flue. A condensing boiler pulls extra heat out of its exhaust with a second heat exchanger, which is why efficiency is this high and why it vents in PVC and needs a condensate drain.
• 7:1 turndown. The turndown ratio is how low the burner can modulate. The NHB-55H runs anywhere from 8,000 to 55,000 BTU/h, so on a 40-degree day it idles along instead of short cycling, which is easier on the equipment and keeps room temperatures steadier.
• Dual stainless steel heat exchangers. Both the primary and secondary heat exchangers are stainless steel. Navien covers the heat exchanger for 10 years on residential installations.
• Built-in zoning. The control board handles the boiler pump plus three zone pumps or three zone valves without a separate zone panel, so a home with a few heating zones needs less external wiring and hardware.
• Small, wall-hung cabinet. At 17.3 inches wide, 23.8 inches tall and 12.8 inches deep, and 73 pounds, it hangs on the wall and frees the floor space an old cast-iron boiler used to take up.
• Natural gas or propane. Navien ships the propane conversion kit in the box, so the same unit works on either fuel.

Navien NHB-55H installed price and estimate

Installed from $8,211.42. This is a complete installed package from GSHA Services, LTD, not an equipment-only price. The standard boiler installation includes:

• Setting and leveling the boiler, with a floor stand where one is used
• New electrical disconnect, power and control wiring
• Supply and return connections with 1-1/4 in. isolation flanges, a 1/2 in. union and a 1-1/4 in. hydraulic separator
• New 3-speed cast-iron circulator, aquastat (100–240°F), autofill combo valve, expansion tank and hydronic docking station
• 3 in. PVC venting with a sidewall vent kit
• Commissioning kit (Protector F1 and Cleaner F3) for the system water
• Honeywell T4 Pro hydronic thermostat
• Removal of the old boiler, start-up and safety inspection, and a boiler tune-up in the first year

Every boiler installation is custom. The “Installed from” price is the starting installed package for this model with GSHA’s standard installation scope; your final price is confirmed by a free on-site estimate. What changes it: the venting route and length, gas line capacity, condensate drain routing, piping and zoning changes (circulators, zone valves, expansion tank and air separation), water-quality treatment, electrical work, removal of the old boiler, permits, and accessories such as NaviLink controls or manifolds, which are priced separately. Financing available with approved credit.

Schedule Boiler Repair | Request a Boiler Installation Estimate or call (224) 220-3660

What can change the final quote: gas line capacity and length, the venting route and length, where the condensate can drain, water-quality treatment, electrical work, zoning and piping changes to your existing radiators or loops, permits, accessories such as NaviLink Wi-Fi control, and how accessible the boiler location is. The estimate is free, and we put the final number in writing before any work starts. Financing is available with approved credit; see our financing page for details.

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

Navien NHB-55H specifications

Optional add-ons priced separately: NaviLink Wi-Fi control $288.43, NaviLink Lite $153.55, NaviClean magnetic filter $375.58.

Installation and warranty

GSHA Services, LTD is a Navien Service Specialist (NSS) and an authorized Navien dealer, listed on Navien’s installer locator at navieninc.com, with Navien Level 3 trained technicians. For a replacement, we remove the old boiler, hang the new unit, connect it to your existing supply and return piping, run the PVC vent and condensate line, treat the system water, and start it up with a safety inspection. We include a boiler tune-up in the first year.

Navien limited warranty (residential, single-family): 1 year labor, 5 years parts, and 10 years on the heat exchanger, with pro-rated heat exchanger coverage in years 11 through 15. Navien requires installation by a licensed contractor, and the homeowner or installer must provide the installation date to Navien; the warranty follows the boiler at its original installation site. Units bought online through e-commerce channels are not covered under Navien’s resale policy.

GSHA Install-Right coverage: our boiler installation package adds 10-year parts and 10-year labor coverage from GSHA Services, LTD. Labor coverage requires annual GSHA maintenance, and service by anyone other than GSHA voids it. Navien’s warranty and GSHA’s coverage are separate; we explain both in writing at your estimate.

Navien NHB-55H FAQs

How much does a Navien NHB-55H cost installed?

From $8,211.42 as a complete installed package from GSHA Services, LTD, including the boiler, circulator, expansion tank, venting, thermostat, removal of the old boiler and start-up. Gas line, venting route, piping changes and accessories can change the final quote, and the estimate is free.

Does the NHB-55H make hot water for showers and sinks?

No. It is a heating-only boiler. If you want one unit for both heating and hot water, look at a Navien NCB-H combi-boiler, or the NHB-55H can be paired with an indirect water heater tank.

What size home does the NHB-55H heat?

It modulates between 8,000 and 55,000 BTU/h, which fits a smaller house, condo, townhome, or a single addition. The right answer depends on your home’s heat loss, not its square footage alone, so we run that calculation at the estimate and recommend the NHB-80H, NHB-110H or NHB-150H if you need more capacity.

Can it run on propane?

Yes. Navien ships the propane conversion kit in the box, so the same model works on natural gas or propane.

Can the NHB-55H replace my old cast-iron boiler?

Often, yes. It connects to your existing radiators or baseboard loops, vents through PVC instead of a chimney, and needs a condensate drain nearby. Piping and zoning changes, if any, are the main things that affect the quote.

What warranty comes with it?

Navien’s residential warranty is 1 year labor, 5 years parts and 10 years on the heat exchanger. GSHA’s installation package adds 10-year parts and labor coverage from GSHA Services, LTD, which stays in effect as long as GSHA performs annual maintenance on the boiler; service by anyone other than GSHA voids the labor coverage.

Navien NHB-H boiler questions homeowners ask

Do you install and repair Navien NHB-H boilers in my city?

Yes. GSHA Services, LTD installs, services and repairs Navien boilers, including this Navien NHB-H model, across McHenry County and Lake County, Illinois, the northern and western Chicago suburbs and southeastern Wisconsin, from our Woodstock and Lake Bluff locations. GSHA is a Navien Service Specialist (NSS), approved June 30, 2026, is listed on Navien’s installer locator at navieninc.com, and sends Navien Level 3 trained technicians. Check the service-area page or call (224) 220-3660 to confirm your address.

Can my existing or discontinued Navien boiler be repaired?

Yes. GSHA Services, LTD repairs existing Navien boilers within its service area, including earlier NHB models that Navien no longer sells. A discontinued model does not automatically need to be replaced; if parts are available and the stainless steel heat exchangers are sound, repair is usually the sensible first step. As a Navien Service Specialist (NSS), GSHA diagnoses the fault, checks parts availability and gives you a repair-or-replace recommendation before any work starts.

What is the difference between a combi boiler and a heating-only boiler?

This Navien NHB-H model is a heating-only condensing boiler: it heats your home through radiators, baseboard or radiant floors but does not make domestic hot water. For showers and taps it needs an indirect water heater fed by the boiler or a separate water heater (tank or tankless). A combi boiler such as the Navien NCB-H or NFC-H does both jobs in one cabinet, and a tankless water heater makes hot water only. A heating-only boiler with an indirect tank is often chosen when you want a large stored hot-water supply or already have a good water heater; the free on-site estimate helps you decide.

Is this boiler for steam or hot-water heating?

This Navien NHB-H model is a hot-water (hydronic) boiler only; it is not a steam boiler and is not rated for steam in any size. It suits homes with hot-water baseboard, radiators or radiant floor loops. If your home has a steam system (one-pipe radiators with air vents, a sight glass on the boiler), it needs a steam boiler, not this model. The free on-site estimate confirms which system your home has.

What does installation include and what can change the price?

GSHA’s standard installed package for this Navien NHB-H model includes setting and leveling the boiler on a floor stand, a new electrical disconnect with power and control wiring, supply and return connections with isolation flanges, a new three-speed circulator, an aquastat, an automatic fill valve, a hydraulic separator, an expansion tank, a hydronic docking station, 3-inch PVC venting with a sidewall vent kit, the system commissioning kit, a hydronic thermostat, removal of the old equipment, a one-year boiler tune-up, and start-up with a safety inspection. Every installation is custom, so the venting route, gas line capacity, condensate drainage, piping and zoning changes, water treatment, electrical work, permits and accessories such as NaviLink, an indirect water heater or manifolds can change the final price. The free on-site estimate confirms it.

When does repair make more sense than replacement?

Repair usually makes sense when the boiler is younger, the heat exchangers are sound, the fault is a single part such as a sensor, igniter, circulator or gas valve, and parts are available. Replacement becomes the better choice when a heat exchanger is leaking or cracked, repairs are repeating every season, parts for an older model are hard to get, the unit is the wrong size for the home, or there is a venting or gas safety concern. An older non-condensing boiler running well below 90% AFUE is another reason to compare the two. GSHA gives you both options with honest reasoning during a service visit or a free on-site estimate.

Get a Navien NHB-55H installation estimate

Tell us about your home and current heating system, and we will size the boiler, confirm the installation scope and give you a written price. GSHA Services, LTD serves McHenry County and Lake County, IL, and the surrounding Chicago suburbs and southeastern Wisconsin from our Woodstock and Lake Bluff locations; see our service area.

Request an Installation Estimate or call (224) 220-3660. Compare all sizes on our Navien boilers and prices page, learn more about boiler installation, or see Navien water heaters and prices if you also need domestic hot water.