Navien NHB-055 User manual

WARNING
If the information in these instructions is not followed exactly, a fire or explosion may result, causing
property damage, personal injury, or death.
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
WHAT TO DO IF YOU SMELL GAS

Do not try to light any appliance.

Do not touch any electrical switch; do not use any phone in your building.

Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency or the gas
supplier.
The installation must conform with local codes or, in the absence of local codes, the National Fuel
Gas Code, ANSI Z223.1/NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Code.
Keep this manual near this boiler for future
reference whenever maintenance or service
is required.
Installation & Operation Manual
NHB Condensing Boilers
Model
NHB-055
NHB-080
NHB-110
NHB-150

22
Requirements for the State of Massachusetts
NOTICE BEFORE INSTALLATION
This appliance must be installed by a licensed plumber or gas fitter in accordance with the Massachusetts Plumbing and Fuel Gas Code 248
CMR Sections 4.00 and 5.00.
IMPORTANT: In the State of Massachusetts (248 CMR 4.00 & 5.00)
For all side wall horizontally vented gas fueled equipment installed in every dwelling, building or structure used in whole or in part for
residential purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than
seven (7) feet above finished grade in the area of the venting, including but not limited to decks and porches, the following requirements shall
be satisfied:
1. INSTALLATION OF CARBON MONOXIDE DETECTORS. No installation or replacement of a vented gas appliance shall be permitted unless a
battery powered or electrically hard wired carbon monoxide detector is present on the same floor as the appliance or on the next adjacent
floor when the appliance is located in a crawl space unless the appliance is located in a detached, uninhabitable garage. For all residential
dwellings, a carbon monoxide detector must also be present on each habitable level of the dwelling. These requirements shall not be
deemed to waive any additional requirements imposed by M.G.L. c. 148 §26F1/2.
2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as required in accordance with the above provisions shall
comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.
3. SIGNAGE. Whenever any through-the-wall vent is installed less than seven feet above the finished grade, a metal or plastic identification
plate shall be permanently mounted to the exterior of the building at a minimum height of eight feet above grade directly in line with the
exhaust vent terminal. The sign shall read, in print size no less than 0.5 inches in size,“GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS”.
4. INSPECTION. The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve the installation
unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with the provisions of
248 CMR 5.09 and 5.12.

3Contents
Contents
1. About the Boiler 6
1.1 Included Items 6
1.2 Accessories 6
1.3 Specifications 7
1.4 Components 9
1.5 Dimensions 11
1.6 Rating Plate 12
2. Installing the Boiler 13
2.1 Choosing an Installation Location 13
2.2 Mounting the Boiler to the Wall 15
3. Installing the System Piping 16
3.1 Installing a Space Heating System 16
3.2 Connecting the Condensate Drain 22
3.3 Filling the System 24
3.4 Testing the Water System 24
3.5 Examples of System Applications 25
3.6 Examples of Electrical Connections 31
4. Connecting the Gas Supply 36
4.1 Gas Pipe Sizing Tables 38
4.2 Measuring the Inlet Gas Pressure 39
5. Venting the Boiler 41
5.1 Selecting a Vent Type 41
5.2 Selecting Vent Pipe Materials 45
5.3 Measuring Vent Length 45
5.4 Terminating the Vent 46
6. Setting the DIP Switches 48
6.1 PCB DIP Switches 48
6.2 Front Panel Dip Switches 49
7. Connecting the Power Supply 50
8. Installing a Cascade System
51
8.1 Connecting Water Supplies 51
8.2 Connecting the Communication Cables 55
9. Installing a Common Vent System 57
9.1 About the Common Vent System 57
9.2 Navien Backflow Damper (Back-draft Damper) 62
9.3 Starting the Common Vent System 63
9.4 Connecting and Terminating the Vent Pipe 65
9.5 Setting Up the Common Vent System 66
9.6 Common Vent Termination Clearances 66
9.7 Exhaust Vent Termination Clearances (For Direct Vent) 68
9.8 Maintenance
69
10. Installation Checklist 70
11. Operating the Boiler
73
11.1 Turning the Boiler On or Off 73
11.2 Adjusting the Temperature 73
11.3 Viewing Basic Information 74
11.4 Viewing Service Information 75
11.5 Setting the Operation Mode 77
11.6 Setting the Parameters 78
11.7 Resetting the Boiler 85
12. Appendixes 86
12.1 Gas Conversion 86
12.2 Wiring Diagram 91
12.3 Ladder Diagram 92
12.4 Component Assembly Diagrams and Parts Lists 93
12.5 Outdoor Temperature Sensor 99
12.6 Outdoor Reset Control 100

4 Safety Information
The following safety symbols are used in this manual. Read and
follow all safety instructions in this manual precisely to avoid
unsafe operating conditions, fire, explosion, property damage,
personal injury, or death.
DANGER
Indicates an imminently hazardous situation which, if not
avoided, could result in severe injury or death.
WARNING
Indicates a potentially hazardous situation which, if not
avoided, could result in injury or death.
CAUTION
Indicates a potentially hazardous situation that, if not avoided,
could result in property damage.
DANGER
If you smell gas:
Do not try to light any appliance.
Do not touch any electrical switches or use landline phones.
From a neighbor’s phone, call your gas provider and follow
their instructions.
If you cannot reach your gas provider, call the fire
department.
Do not return to your home until authorized by your gas
supplier or the fire department.
Do not use or store flammable products, such as gasoline,
solvents, or adhesives in the same room or area as the
boiler.
The boiler has a main burner flame that can turn on at
any time and can ignite flammable vapors. Vapors from
flammable liquids can explode and catch fire, causing death
or severe burns.
Vapors cannot be seen and are heavier than air. They can
travel long distances along the ground and can be carried
from other rooms to the boiler’s main burner flame by air
current.
Keep all flammable products far away from the boiler and
store them in approved containers. Keep the containers
closed tightly and out of the reach of children and pets.
Safety Information

5Safety Information
CAUTION
Do not turn on the boiler unless the water and gas
supplies are fully opened.
Doing so may damage the boiler.
Do not use this boiler for anything other than its
intended purpose, as described in this manual.
Do not remove the front cover unless the power to the
boiler is turned off or disconnected.
Failure to do so may result in electric shock.
When servicing the controls, label all wires prior to
disconnecting them.
Failure to do so may result in wiring errors, which can lead to
improper or dangerous operation. Verify proper operation
after servicing.
Do not use unapproved replacement or accessory parts.
Doing so may result in improper or dangerous operation
and will void the manufacturer’s warranty.
Do not place anything in or around the vent terminals,
such as a clothes line, that could obstruct the air flow in
or out of the boiler.
This boiler has been approved for use in the USA and
Canada only.
Using the boiler in any other country will void the
manufacturer’s warranty.
WARNING
Do not store or use gasoline or other flammable liquids
near this boiler.
Doing so may result in fire or explosion.
Do not place combustibles, such as newspapers or
laundry, near the boiler or venting system.
Doing so may result in a fire.
Do not place or use hair sprays, spray paints, or any other
compressed gases near the boiler or venting system,
including the vent termination.
Doing so may result in fire or explosion.
Do not operate the boiler with the front cover opened.
Doing so may result in fire or carbon monoxide (CO)
poisoning, which may result in property damage, personal
injury, or death.
Do not operate this boiler without proper venting.
Doing so may result in fire or carbon monoxide (CO)
poisoning, which may result in property damage, personal
injury, or death.
Do not touch the power cord or internal components of
the boiler with wet hands.
Doing so may result in electric shock.

6 About the Boiler
1.1 Included Items
When you open the box, you will find the following items with
the boiler. Check the box for each of the following items before
installing the boiler.
Installation & Operation Manual,
User’s Information Manual Quick Installation Manual
2 in Vent Termination Caps (x2) 2 in Wall Flanges (x4)
Spare Parts Air Vent
Wall Mounting Bracket Tapping Screws & Anchors (x4)
Pressure Relief Valve, Heating Conversion Kit
Outdoor Temperature Sensor and
Cable Air Vent Bushing (3/4in to 1/2in)
1. About the Boiler
1.2 Accessories
The following optional accessories are available for the boiler.
Navien Manifold System
(for primary zone)
Navien Manifold System
(for secondary zone)
Condensate Neutralizer Kit Zone Controller
(FMZ-20/30)
Zone Controller
(FMZ-40/60)
System Supply/Return
Temperature Sensors
Navi-Link
(Wi-Fi Control System) Ready-Link Rack

7About the Boiler
1.3 Specifications
The following tables list the specifications for the boiler. Additional specifications for water, gas, electricity, and vent connections are provided
in the Installation section.
Space Heating Specifications
Navien Condensing Boiler
Space Heating Ratings Other Specifications
Model Number
1
Heating Input (MBH) Heating
Capacity
2
(MBH)
Net AHRI
Rating Water
3
(MBH)
AFUE
2
(%) Water
Pressure
Water
Connection
Size (Supply,
Return)
Min Max
NHB-055 8 55 51 44 95
12–30 psi 1 in NPT
NHB-080 8 80 74 64 95
NHB-110 10 110 102 89 95
NHB-150 10 150 138 120 95
Note 1. Ratings are the same for natural gas models converted to propane use.
2. Based on U.S. Department of Energy (DOE) test procedures.
3. The net AHRI water ratings shown are based on a piping and pickup allowance of 1.15. Consult Navien before selecting a boiler
for installations having unusual piping and pickup requirements, such as intermittent system operation, extensive piping
system, etc.

8 About the Boiler
General Specifications
Item NHB-055 NHB-080 NHB-110 NHB-150
Dimensions 17in (W) x 12in (D) x 24in (H) 17in (W) x 13in (D) x 24in (H)
Weight 73 lb (33 kg) 80 lb (36 kg)
Installation Type Indoor Wall-Hung
Venting Type Forced Draft Direct Vent
Ignition Electronic Ignition
Natural Gas Supply Pressure (from source) 3.5 in–10.5 in WC
Propane Gas Supply Pressure (from source) 8.0 in–13.5 in WC
Natural Gas Manifold Pressure -0.03 in WC -0.08 in WC -0.10 in WC -0.40 in WC
Propane Gas Manifold Pressure -0.03 in WC -0.07 in WC -0.09 in WC -0.30 in WC
Gas Connection Size 3/4 in NPT
Power Supply
Main Supply 120V AC, 60Hz
Maximum Power
Consumption Less than 10 amperes
Materials Casing Cold-rolled carbon steel
Heat Exchangers Primary and Secondary: Stainless Steel
Venting
Exhaust 2 in or 3 in PVC, CPVC, approved polypropylene*
2 in or 3 in Special Gas Vent Type BH (Class III, A/B/C)
Intake 2 in or 3 in PVC, CPVC, polypropylene
2 in or 3 in Special Gas Vent Type BH (Class III, A/B/C)
Vent Clearance 0 in to combustibles
Safety Devices
Flame Rod, APS, Ignition Operation Detector
Water Temperature High Limit Switch, Exhaust Temperature High Limit Sensor, Water
Pressure Sensor
*Approved polypropylene systems include:
Duravent Polypro (Single Wall): 2PPS-xxx (2”), 3PPS-xxx (3”)
Centrotherm Innoflue SW: ISxx02xx (2”), ISxx03xx (3”)
Refer to manufacturer’s literature for detailed information.
Temperature Setting Range
Item Temperature Setting Range Remarks
Space Heating
Supply 77–194°F (25-90°C) Actual supply and return temperatures vary
depending on the selected outdoor reset
curve.
Return 68–158°F (20-70°C)
Note For more information about the space heating temperature setting range, refer to“Setting the Heat Load for the Outdoor Reset
Control Mode” on page 79.

9About the Boiler
1.4 Components
The following diagram shows the key components of the boiler. Component assembly diagrams and particular parts lists are included in the
Appendixes.
Intake Air
Air Filter
Front Panel
Exhaust
Flue Duct
Space Heating
Supply
APS
PCB
Power Switch
Air Vent Connection
LWCO

10 About the Boiler
Dual Venturi
Ignition Transformer
Igniter & Flame Rod
Primary Heat Exchanger
Mixing Gas
Guide
Secondary Heat Exchanger
Condensate Trap
Gas Connection
Space Heating
Return
Gas Valve
Fan & Motor
Metal Fiber
Premix Burner