Navien NHB-H Series Condensing Boiler | Ultra-High Efficiency
The Navien NHB-H Series Condensing Boilers is an ultra-high-efficiency, wall-hung condensing heating boiler available in four sizes from 55,000 to 150,000 BTU/h maximum input. With 95% AFUE, stainless steel heat exchangers, built-in zoning controls, and flexible direct-vent options, the NHB-H is designed for efficient hydronic heating applications.
The series is available for natural gas and can be converted to propane using the applicable conversion kit. Proper boiler selection requires a heat-loss calculation and consideration of the existing hydronic system.
Navien NHB-H Series – Supplied & Professionally Installed by 4Most Energy
The Navien NHB-H Series is designed for high-efficiency hydronic heating with a wall-hung, condensing boiler platform. All four models use dual stainless steel heat exchangers and achieve a listed 95% AFUE. Model sizes range from 55,000 to 150,000 BTU/h maximum heating input, allowing the equipment to be selected according to the heating requirements of the building and hydronic system.
The NHB-H incorporates a built-in control system for boiler pump and zone control applications. Navien specifies control capability for a boiler pump, three zone valves, three zone pumps, or two zone pumps plus an indirect pump. The user interface includes a backlit display, click-wheel control, and Setup Wizard.
Venting is an important part of the installation. The NHB-H uses forced-draft direct venting and supports 2-inch or 3-inch vent configurations. Navien lists maximum vent lengths of up to 65 feet with 2-inch venting and up to 150 feet with 3-inch venting, subject to the installation requirements and approved vent materials.
The boiler also uses a negative-pressure regulating gas valve and dual-venturi combustion system for air/gas ratio control. Natural-gas and propane supply pressures must meet Navien's specified requirements, and the installation includes electrical, gas, condensate, hydronic piping, combustion-air, and exhaust considerations.
Correct sizing is essential. A boiler should not be selected based solely on floor area. Navien recommends determining the required boiler size from a building heat-loss calculation, taking insulation, windows, doors, structure, and other heat-loss factors into account.
4Most Energy will assess the existing heating system, verify application requirements, select the appropriate NHB-H output, and complete the installation and commissioning according to applicable manufacturer and code requirements.
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Why Install the Navien NHB-H Series with 4Most Energy?
HVAC Expertise
Experienced HVAC professionals evaluate the boiler and hydronic system as a complete heating application.
Certified Technicians
Qualified technicians handle gas, electrical, venting, hydronic connections, testing, and commissioning.
Premium Installation Materials
Installation materials are selected according to equipment requirements, system design, and applicable code.
Transparent Pricing
Receive a clear installation scope before work begins, helping you understand what is included.
After-Sales Support
4Most Energy provides ongoing support for equipment operation, maintenance, and service needs.
Parts Availability
Access to appropriate replacement components helps support efficient future service and repairs.
Proper System Sizing
Boiler selection is based on heating requirements rather than simply matching equipment to floor area.
- 95% AFUE high-efficiency condensing operation across the four listed models.
- Dual stainless steel heat exchangers designed for condensing boiler operation.
- Wide modulation range with TDRs of 7:1, 10:1, 11:1, and 15:1 depending on model.
- Built-in zoning control for multiple zone control configurations.
- Smart user controls featuring a backlit LCD display, click-wheel control, and Setup Wizard.
- Flexible direct venting supporting 2-inch and 3-inch vent configurations.
- Negative-pressure regulating gas valve paired with dual venturi combustion control.
- Field gas convertibility for natural gas high-altitude applications and propane, subject to Navien's specified conversion requirements.
| Specification | NHB-55H | NHB-80H | NHB-110H | NHB-150H |
|---|---|---|---|---|
| Maximum Heating Input | 55,000 BTU/h | 80,000 BTU/h | 110,000 BTU/h | 150,000 BTU/h |
| Minimum Heating Input | 8,000 BTU/h | 8,000 BTU/h | 10,000 BTU/h | 10,000 BTU/h |
| Heating Capacity | 51,000 BTU/h | 74,000 BTU/h | 102,000 BTU/h | 138,000 BTU/h |
| Net AHRI Rating, Water | 44,000 BTU/h | 64,000 BTU/h | 89,000 BTU/h | 120,000 BTU/h |
| AFUE | 95% | 95% | 95% | 95% |
| TDR | 7:1 | 10:1 | 11:1 | 15:1 |
| Fuel | Natural Gas / Propane Conversion | Natural Gas / Propane Conversion | Natural Gas / Propane Conversion | Natural Gas / Propane Conversion |
| Installation | Indoor Wall-Hung | Indoor Wall-Hung | Indoor Wall-Hung | Indoor Wall-Hung |
| Venting Type | Forced Draft Direct Vent | Forced Draft Direct Vent | Forced Draft Direct Vent | Forced Draft Direct Vent |
| Electrical | 120V AC, 60Hz | 120V AC, 60Hz | 120V AC, 60Hz | 120V AC, 60Hz |
| Maximum Power Consumption | Less than 10A | Less than 10A | Less than 10A | Less than 10A |
| Dimensions | 17.3"W × 23.8"H × 12.8"D | 17.3"W × 23.8"H × 12.8"D | 17.3"W × 23.8"H × 12.8"D | 17.3"W × 23.8"H × 12.8"D |
| Weight | 73 lbs | 73 lbs | 80 lbs | 80 lbs |
| Gas Connection | 3/4" NPT Male | 3/4" NPT Male | 3/4" NPT Male | 3/4" NPT Male |
| Max. 2" Vent Length | 65 ft | 65 ft | 65 ft | 65 ft |
| Max. 3" Vent Length | 150 ft | 150 ft | 150 ft | 150 ft |
| Model | Maximum Input | Heating Capacity | General Application |
|---|---|---|---|
| NHB-55H | 55,000 BTU/h | 51,000 BTU/h | Lower heating-load hydronic systems |
| NHB-80H | 80,000 BTU/h | 74,000 BTU/h | Moderate heating-load hydronic systems |
| NHB-110H | 110,000 BTU/h | 102,000 BTU/h | Higher heating-load hydronic systems |
| NHB-150H | 150,000 BTU/h | 138,000 BTU/h | Higher-capacity hydronic heating systems |
Do not select an NHB-H boiler solely by home square footage.
Navien states that boiler sizing should be based on a building heat-loss calculation. The required output depends on factors including the building structure, insulation, doors, windows, and system requirements.
4Most Energy recommendation: Have the existing or proposed heating system evaluated before selecting the boiler size. The correct model should provide sufficient heating capacity without unnecessarily oversizing the equipment.
| Step | Process Phase | Description |
|---|---|---|
| Step 1 | Request Installation Quote | Contact 4Most Energy to discuss your existing boiler, heating system, property, and replacement requirements. |
| Step 2 | System Sizing Consultation | We evaluate the heating load and existing hydronic system to determine the appropriate boiler capacity. |
| Step 3 | Equipment Recommendation | Based on the application, we recommend the appropriate NHB-H model and installation configuration. |
| Step 4 | Installation Scheduling | Once the installation scope is approved, we coordinate an installation date. |
| Step 5 | tRemoval of Existing Equipmen | Where applicable, the existing boiler is disconnected and removed as part of the approved installation scope. |
| Step 6 | Installation & System Connection | The new Navien boiler is installed and connected to the required gas, electrical, venting, condensate, hydronic, and control systems. |
| Step 7 | Safety Testing | Gas, combustion, electrical, venting, controls, and system connections are checked as applicable. |
| Step 8 | Final Commissioning | The boiler is started, configured, tested, and commissioned for operation. |
| Warranty Coverage | Residential Applications | Commercial Applications |
|---|---|---|
| Labor Warranty | 1 Year | 1 Year |
| Parts Warranty | 5 Years | 3 Years |
| Heat Exchanger – 100% Manufacturer Coverage | Years 1–10 | Years 1–7 |
| Pro-Rated Heat Exchanger Coverage | Through Year 15 | Through Year 10 |
Warranty coverage is subject to Navien's terms, proper installation, operation, and maintenance requirements.
Warranty Claim Process
For warranty service, the homeowner should generally contact the original installer. The installer or qualified service provider works with Navien according to the manufacturer's warranty procedures. Proof of installation and other required information may be necessary.
4Most Energy Labour Warranty
4Most Energy labour warranty coverage should be provided according to the terms stated in the customer's installation agreement and invoice.
Optional Maintenance Plan
Maintenance Plans Starting From $12.99/Month
Regular boiler maintenance can help identify operating issues before they develop into larger service problems.
Maintenance-plan benefits can include:
- Scheduled system inspections
- Boiler performance checks
- Combustion and operating checks
- Inspection of key components
- Identification of potential service issues
- Ongoing maintenance support
Enrollment: Customers can request maintenance-plan availability and current plan terms from 4Most Energy.
Service Area
Greater Toronto Area (GTA) and surrounding regions
Toronto, Markham, Richmond Hill, Vaughan, Aurora, Newmarket, Scarborough, Brampton, and Mississauga.
Extended Service Area: Stouffville, Oshawa, Barrie, Orangeville, Hamilton, St. Catharines, Guelph, Kitchener.
