Navien NHB-055 Installation & Operation Manual
  1. Manuals
  2. Brands
  3. Navien Manuals
  4. Boiler
  5. NHB-055
  6. Installation & operation manual

Navien NHB-055 Installation & Operation Manual

Condensing boiler
Hide thumbs Also See for NHB-055:
Table of Contents

Advertisement

Quick Links

See also: Service Manual , User's Information Manual
Installation & Operation Manual
NHB Condensing Boilers
Model
NHB-055
NHB-080
NHB-110
NHB-150
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.

Advertisement

Table of Contents
loading

Related Manuals for Navien NHB-055

Summary of Contents for Navien NHB-055

  • Page 1 Installation & Operation Manual NHB Condensing Boilers Model NHB-055 NHB-080 NHB-110 NHB-150 Keep this manual near this boiler for future reference whenever maintenance or service is required. WARNING If the information in these instructions is not followed exactly, a fire or explosion may result, causing property damage, personal injury, or death.
  • Page 2 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...

  • Page 3: Table Of Contents

    9. Installing a Common Vent System 9.1 About the Common Vent System 2. Installing the Boiler 9.2 Navien Backflow Damper (Back-draft Damper) 2.1 Choosing an Installation Location 9.3 Starting the Common Vent System 2.2 Mounting the Boiler to the Wall 9.4 Connecting and Terminating the Vent Pipe...

  • Page 4: Safety Information

    Safety Information The following safety symbols are used in this manual. Read and follow all safety instructions in this manual precisely to avoid DANGER 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.
  • Page 5 CAUTION WARNING 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.

  • Page 6: About The Boiler

    Check the box for each of the following items before installing the boiler. Installation & Operation Manual, Quick Installation Manual User’s Information Manual Navien Manifold System Navien Manifold System (for primary zone) (for secondary zone) 2 in Vent Termination Caps (x2)

  • Page 7: Specifications

    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.
  • Page 8 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...

  • Page 9: Components

    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 Exhaust Air Filter Air Vent Connection Flue Duct LWCO Front Panel Space Heating Supply Power Switch About the Boiler...
  • Page 10 Ignition Transformer Metal Fiber Premix Burner Igniter & Flame Rod Primary Heat Exchanger Mixing Gas Guide Secondary Heat Exchanger Fan & Motor Gas Valve Dual Venturi Gas Connection Condensate Trap Space Heating Return About the Boiler...

  • Page 11: Dimensions

    1 in Condensate Outlet Gas Connection Space Heating Supply 1 in Overhead View Supply Connections 15.9” (405 mm) 6.6” (170 mm) 4.5” (115 mm) 15.8” (401 mm) 6” (152 mm) 17.3” (440 mm) * NHB-055/080: 11.8” (300 mm) About the Boiler...

  • Page 12: Rating Plate

    Installation procedures at normal manifold pressure. For installation instructions at altitudes higher than 4,500 ft, please contact Navien. *Cet appareil est certifié pour une utilisation à des altitudes de 0 à 4,500 pieds (1,370 m) conformément aux toutes les procédures d’installation à...

  • Page 13: Installing The Boiler

    Carefully consider the following factors Navien will not be responsible for water damages that occur as a when choosing an installation location: result. For more information about condensate drainage, refer to “3.2 Connecting the Condensate Drain”...
  • Page 14 Adequate Installation Clearances CAUTION CAUTION It is necessary to leave clearance for service access. Do not install the boiler on carpeting. Clean, Debris and Chemical-free Combustion Air Do not install the boiler in areas where dust and debris may Install the boiler in an area that allows for service and maintenance accumulate or where hair sprays, spray detergents, chlorine, or access to utility connections, piping, filters, and traps.

  • Page 15: Mounting The Boiler To The Wall

    2.2 Mounting the Boiler to the Wall WARNING Navien NHB boilers come with an upper mounting bracket that is pre-drilled at 16 in (400 mm) on center for easy installation on The boiler is heavy. Always lift the unit with assistance. Be standard wall studs.

  • Page 16: Installing The System Piping

    All systems, old and new, system. Freeze protection for new or existing systems requires must be cleaned to remove flux, grease and carbon residue. Navien specially formulated glycol, which contains inhibitors to prevent recommends cleaning the boiler system with cleaning products the glycol from attacking the metallic system components.
  • Page 17 (oxygen) and other impurities. To avoid the presence of oxygen, ensure all of the air is removed from The Navien NHB boiler comes with an air vent and an adapter the system during commissioning via strategically placed and bushing that must be connected to the air vent connection.
  • Page 18 Internal LWCO Install a backflow preventer valve in the make-up water supply to the unit as required by local codes. The Navien NHB boiler is equipped with a factory-installed, pressure-sensing type low water cutoff (LWCO) device. The Expansion Tank minimum operation pressure for this device is 6 psi by default.
  • Page 19 Method 2 it is installed in a manifold system. in, 30 psi (max.) pressure relief valve on the space heating hot If the installed system does not have a Navien manifold system, water outlet. An ASME approved HV pressure relief valve for space install a pressure relief valve with the air vent.
  • Page 20 Space Heating Supply The following tables list the specifications for the available pumps and Navien's manifold system. If you are not using one of the pumps listed below, you must use a circulator with check valve installed at pump outlet or a pump with an integral check valve.
  • Page 21 PQ Curves NHB-055/080 NHB-110 Q[GPM] Q[GPM] NHB-150 Q[GPM] Temperature Rise Conditions 20°F ΔT 30°F ΔT 40°F ΔT Model Flow Rate (GPM) Head (Ft) Flow Rate (GPM) Head (Ft) Flow Rate (GPM) Head (Ft) NHB-055 NHB-080 15.2 NHB-110 10.2 11.3 NHB-150 13.8...

  • Page 22: Connecting The Condensate Drain

    (refer to "3.2.1 Condensate Neutralizer Kit" on page 23). The Navien NHB boiler creates condensation when it operates. This condensation has an acidic pH of 3-5. Follow all local codes If you choose this option, the neutralizing agent Note and regulations when disposing of condensate from the boiler.
  • Page 23 Do not connect more than one appliance to the neutralizer. If option 'b' (p. 22) is selected as the disposal option, the Navien condensate neutralizer kit is recommended. The condensate from the appliance flows through the neutralizing media and increases the pH of the condensate.

  • Page 24: Filling The System

    If the pH level is not specified, replace the neutralizing media when the pH is below 6.0. For replacement media, contact your local Navien distributor. Pressure Relief Valve Air Separator 3.3 Filling the System...

  • Page 25: Examples Of System Applications

    Read and follow the guidelines listed below when installing system Sulfate 205 mg/l piping for the Navien NHB boiler: System application drawings are intended to explain the system 2. Close the manual and automatic air vents and the boiler drain piping concept only.
  • Page 26 Refer to the "3.1.1 Guidelines for a Space Heating Installation" on page 34 for wiring connections. Air Handler Interface The Navien NHB boiler can control the operation of an air WARNING handler when a thermostat is used in combination with the air handling unit.
  • Page 27 3.5.2 System Application - Zone System with Zone Valves Additional Zone Zone #2 Zone #1 Zone Valve System Pump (Typical) Air Separator Return filter Not to exceed 4 pipe Dia or Max. 12" Make-up Water Backflow preventer Pressure reducing valve Expansion Tank Boiler Pump System application drawings are intended to explain the system piping concept only.
  • Page 28 3.5.3 System Application - Zone System with Pumps Additional Zone Zone #2 Zone #1 Air Separator Return filter Not to exceed 4 pipe Dia or Max. 12" Make-up Water Backflow preventer Pressure reducing valve Expansion Tank Boiler Pump System application drawings are intended to explain the system piping concept only. Note Install a filter in the system return to remove foreign objects from the system.
  • Page 29 3.5.4 System Application - Air Handler System Return filter Air Separator System Pump (Boiler Pump) Make-up Water Backflow preventer Expansion Tank Pressure reducing valve Air Flow Air Handler System application drawings are intended to explain the system piping concept only. Note Install a filter in the system return to remove foreign objects from the system.
  • Page 30 3.5.5 System Application - DHW System with Indirect Tank System Pump Air Separator Return filter Make-up Water Backflow preventer Pressure reducing valve Expansion Tank DHW Outlet Anti-scald mixing valve Indirect Tank Boiler Pump DHW Pump DHW Inlet System application drawings are intended to explain the system piping concept only. Note Install a filter in the system return to remove foreign objects from the system.

  • Page 31: Examples Of Electrical Connections

    3.6.2 Wiring Diagram - External LWCO 3.6 Examples of Electrical Connections WARNING Improperly connecting the electrical supplies can result in electrical shock and electrocution. Follow all applicable electrical codes of the local authority having jurisdiction. CN10 CN12 CN24 CN25 CN29 CN30 Connecting the electrical components should be performed only by a licensed professional.
  • Page 32 3.6.3 Wiring Diagram - the Navien SmartZone + When Navien boilers are used with a Navien Smartzone+ zone pump controller, an RS-485 data communication link is established through the Ready-link connection. This allows the controller and the boiler to share operational information and to control the zones more efficiently by minimizing unnecessary pump operation.

  • Page 33: Zone Valves

    3.6.4 Wiring Diagram - Generic Zone System with 3.6.5 Wiring Diagram - Generic Zone System with Zone Valves Circulators <NHB> <NHB> CN10 CN12 CN24 CN25 CN29 CN30 CN10 CN12 CN24 CN25 CN29 CN30 System System AC24V System System AC24V LWCO Supply LWCO Supply...
  • Page 34 Indirect Tank T/T If you are using the navien manifold system, connect the pump wires to the system pump. If you are not using the navien manifold system, connect the pump wires to either the system pump or the boiler pump.
  • Page 35 3.6.8 Wiring Diagram - Optional Supply/Return Temperature Sensors <NHB> CN10 CN12 CN24 CN25 CN29 CN30 System AC24V System LWCO Supply Return Output Temp. Temp. (optional) (optional) Temperature sensor Cable tie Thermal insulation Refer to "6.1 PCB DIP Switches" on page 48 to control the boiler supply or return water temperature using the external Note temperature sensors, and set the DIP switches accordingly.

  • Page 36: Connecting The Gas Supply

    This boiler cannot be converted from natural gas to propane or vice versa without a Navien gas conversion kit. Do not 5. Install full port valves on the gas supply line and boiler. attempt a field conversion of this boiler without a Navien gas 6.
  • Page 37 When using rigid pipe, Navien recommends the installation of a union on the gas supply line close to the boiler, to facilitate any future maintenance or service.

  • Page 38: Gas Pipe Sizing Tables

    4.1 Gas Pipe Sizing Tables The following tables are referenced from 2012 National Fuel Gas Code for reference only. Please consult the gas pipe manufacturer for actual pipe capacities. Maximum Natural Gas Delivery Capacity In Cubic Feet (ft ) per Hour (0.60 Specific Gravity; 0.5 in WC Pressure Drop). Contact your gas supplier for BTU/ft ratings.

  • Page 39: Measuring The Inlet Gas Pressure

    Maximum Liquefied Propane Delivery Capacity In Thousands of BTU/H (0.5 in WC pressure drop) Length (including fittings) Pipe Size 10 ft 20 ft 30 ft 40 ft 50 ft 60 ft 80 ft 100 ft 125 ft 150 ft 175 ft 200 ft 250 ft (3 m)
  • Page 40 To measure the inlet gas pressure: 9. Remove the front cover by loosening the 4 Phillips head screws securing it to the case. 1. Shut off the manual gas valve on the gas supply line. Opened Closed Gas Valve 10. Loosen the screws indicated in the figure below and connect a manometer to the pressure port.

  • Page 41: Venting The Boiler

    Navien also recommends installing a new vent system with this For best results, keep the venting system as short and straight as appliance. If reusing an existing vent system, thoroughly inspect possible.
  • Page 42 Description Canadian Direct Vent Installations US Direct Vent Installations Clearance above grade, veranda, porch, deck, or balcony 12 in (30 cm) 12 in (30 cm) Clearance to window or door that may be opened 36 in (91 cm) 12 in (30 cm) Clearance to permanently closed window Vertical clearance to ventilated soffit located above the terminal within a horizontal distance of 2 ft (61 cm) from...
  • Page 43 Vent Pipe 2" problem, any freezing damage which occurs from back drafting will not be covered by the Navien warranty. If there is any question about the possibility of back drafting in the installation location, use a direct venting system for the boiler.
  • Page 44 Canadian Non-Direct Vent US Non-Direct Vent Description Installations Installations Clearance above grade, veranda, porch, deck, or balcony 12 in (30 cm) 12 in (30 cm) 48 in (120 cm) below or to side Clearance to window or door that may be opened 36 in (91 cm) of opening;...

  • Page 45: Selecting Vent Pipe Materials

    140°F (60°C) respectively. 5.2 Selecting Vent Pipe Materials Venting requirements differ in the US and Canada. Consult the When PCB DIP switch 2 #8 is set to Off (factory Note following chart or the most recent edition of ANSI Z223.1/NFPA default), the boiler does not operate without an 54 or CAN/CGA B149.1, as well as all applicable local codes and exhaust thermostat installed.

  • Page 46: Terminating The Vent

    Indoor Boiler Installation Venting Examples 5.4 Terminating the Vent The following are some possible indoor venting options: Before installing the boiler, determine what type of vent termination is appropriate for the installation location and 2 in or 3 in Two-pipe Sidewall Venting situation.
  • Page 47 Non-concentric Sidewall Venting – Air is drawn from a different 2 in or 3 in Two-pipe Vertical Venting – Intake and exhaust pipes location that is at least 12 in (300 mm) away from the exhaust do not have to terminate in the same area. termination.

  • Page 48: Setting The Dip Switches

    6. Setting the DIP Switches Dip Switch 2 (8 switch unit) CAUTION The DIP SW 2 on the circuit board configures the temperature control modes, country, and enables or disables the space heating Do not remove the front cover unless the power to the thermostat.

  • Page 49: Front Panel Dip Switches

    Dip Switch 2 (2 switch unit) 6.2 Front Panel Dip Switches The DIP SW 2 on the front panel configures settings for the type of Dip Switch 1 (10 switch unit) gas. Before changing the settings, lift the rubber cover to access the The DIP SW 1 on the front panel configures the temperature unit front panel DIP switches.

  • Page 50: Connecting The Power Supply

    Do not connect the boiler to a 220-240V AC power supply. Doing so will damage the boiler and void the warranty. All the Navien NHB boilers are supplied with a factory-installed, 3-pronged (grounded) plug. The boiler’s current rating is 5 A and can be plugged into any grounded electrical outlet adjacent to the boiler.

  • Page 51: Installing A Cascade System

    Use pumps with integral check valves or install check valves at the pump outlets. Navien system supply/return temperature sensors (#GXXX001417) must be installed for cascade system operation. Adjust the settings at the master unit as the cascade system uses only the master unit settings. Changes made to the slave units are ignored.
  • Page 52 System Application #1- Cascade System with Closely Spaced Tees Supply Air separator Slave2 Slave1 Master Cold water Back flow preventor Expansion tank Temperature 12” (30 cm) sensors (required) maximum Return Connect the “CH Demand (CH T/T or Zone controller)” to the master unit. Note Connect the supply/return sensors to CN29 (supply) and CN30 (return) terminals on the master unit PCB.
  • Page 53 System Application #3- Cascade System with DHW Indirect Tank (for High DHW Demand) Air separator Supply Cold water Back flow preventor Expansion tank Indirect tank Slave1 Master Slave2 Aquastat Temperature 12” (30 cm) sensors (required) maximum Return Cold water In this configuration, the full capacity of all boilers will be prioritized to the DHW demand. Note The aquastat on the DHW indirect tank must be connected to the master unit.
  • Page 54 System Application #5- Cascade System with DHW Indirect Tank (for Low DHW Demand) Supply Indirect Air separator tank Slave2 Slave1 Master Cold water Back flow preventor Expansion tank Aquastat Temperature 12” 30 cm sensors (required) maximum Cold water Return In this configuration, space heating and DHW can operate simultaneously. Note The aquastat on the DHW indirect tank must be connected to a slave unit.

  • Page 55: Connecting The Communication Cables

    8.2 Connecting the Communication Cables When plumbing a cascade system, consider the following pipe Up to 16 boilers can be connected with Navien Ready-Link diameters and flow rates. Note that flow rates above 4 ft/s may communication cables. Select one of the boilers in the cascade cause pipe erosion or velocity noise.
  • Page 56 2. On the slave boiler, press and hold the Diagnostic and Down(- ) buttons for more than 2 seconds. “SL.01” will appear on the display to confirm that this boiler is set as a slave. 3. Repeat step 2 to configure the rest of the slave boilers in the system.

  • Page 57: Installing A Common Vent System

    The Navien Common Vent System* provides an easy way to install the “Included Items” on page 62). the vent system for up to 8 Navien NHB boiler units. By sharing the main intake and exhaust vent pipes, effective system venting...
  • Page 58 Adequate Installation Clearances CAUTION It is necessary to leave clearance for service access. CAUTION Do not install the boiler on carpeting. Clean, Debris and Chemical-free Combustion Air Do not install the boiler in areas where dust and debris may Install the boiler in an area that allows for service and maintenance accumulate or where hair sprays, spray detergents, chlorine, or access to utility connections, piping, filters, and traps.
  • Page 59 General and Local Standards Information Cutting and Assembling Common Vent System Components When installing and operating the common vent system, the following standards and regulations must be complied with and Standard tools are suitable for the cutting and assembly of adhered to: common vent system components.
  • Page 60 Vent Pipe Pitch and Supports Use approved solvent type cement for the proper Note vent materials. For horizontal runs, slope the horizontal section upward toward Use solvent type cement only. the vent termination at a rate of 1/4” per foot (2% slope). Check the date of manufacture before using the cement.
  • Page 61 9.1.2 Determining the Length of a Common Vent System The following illustration depicts an example of a common vent system installed for a cascade system of 8 Navien NHB boiler units. Follow the instructions listed below to determine the length of a common vent.

  • Page 62: Navien Backflow Damper (Back-Draft Damper)

    Maintenance Port 9.2 Navien Backflow Damper (Back-draft Damper) Navien Backflow Damper has a maintenance port to allow you to easily inspect the operating condition of the damper plate. The Navien backflow damper prevents backflow (back-draft) at the exhaust vent while the boiler unit operates.

  • Page 63: Starting The Common Vent System

    3. Connect the backflow damper to the exhaust duct of the boiler 9.3 Starting the Common Vent System unit. 9.3.1 Backflow Damper Assembly Follow the instructions below to assemble the backflow damper on the NHB boiler unit: 1. Remove the screws from the exhaust vent adapter. 4.
  • Page 64 9.3.2 Connecting the Pipe to the Damper 9.3.3 Assembling the T Joint 1. Insert 2” vent pipe to the backflow damper to start the vent 1. Connect an 8”-to-2” reducer to the 8” tee. Apply solvent run. cement to the mating surfaces. Apply Cement 8”-to-2”...

  • Page 65: Connecting And Terminating The Vent Pipe

    9.4 Connecting and Terminating the Vent Pipe Refer to the following example to install the common vent system. The installation area should be measured to ensure that sufficient space is available to install the boiler units and the common vent system. Ensure that the common vent system is installed near the boiler units while satisfying all clearance requirements that are specified in this manual as well as the Installation Manuals supplied with the boiler units.

  • Page 66: Setting Up The Common Vent System

    9.5 Setting Up the Common Vent System 9.6 Common Vent Termination Clearances DANGER 9.6.1 Direct Vent Application – Vertical Installation Incorrect DIP switch settings may lead to severe personal injury, death, or property damage. 36" min. Exhaust Refer to the following figures when setting DIP switches. Intake 12"...
  • Page 67 9.6.3 Direct Vent Application – Horizontal Installation Exhaust Maximum length 20’ (6 m) Minimum length 36” Intake (91 m) The illustration is intended for reference purposes Note only. Direct the exhaust away from any building openings. During cold weather situations, the temperature of the exhaust will be much warmer than the ambient air.

  • Page 68: Exhaust Vent Termination Clearances (For Direct Vent)

    9.7 Exhaust Vent Termination Clearances (For Direct Vent) Description Canadian Direct Vent Installations1 U.S. Direct Vent Installations2 Clearance above grade, veranda, porch, deck, or 12 in (30 cm) 12 in (30 cm) balcony Clearance to window or door that may be opened 12 in (30 cm) 12 in (30 cm) Clearance to permanently closed window...

  • Page 69: Maintenance

    3. Reinstall the gasket and maintenance port cover, and then fix 9.8 Maintenance them with a set screw. Periodically check the damper condition inside the backflow damper through the maintenance port to ensure optimal performance of the system. Follow the instructions to check the damper condition and replace the backflow damper if necessary.

  • Page 70: Installation Checklist

    To troubleshoot any operational problems refer to “Troubleshooting” in the Owner’s Manual. If you have additional questions or need assistance with installation, contact Technical Support at 1-800-519-8794 or 1-949-420-0420, or refer to the technical support section of Navien’s website (www.navien.com). Installing the boiler...
  • Page 71 Connecting a Pressure Relief Valve Have you installed an approved pressure relief valve on the boiler? Does the rating of the pressure relief valve match or exceed the maximum BTU rating of the boiler? Is the pressure relief valve in on the space heating outlet? Have you installed the pressure relief valve on the space heating supply pipe near the boiler? Have you installed a discharge drain tube from the pressure relief valve to within 6-12 in (150-300 mm) of the floor? Connecting the Condensate Drain...
  • Page 72 PCB DIP switch setting (DIP SW 2, set of 8) Is switch #1 set correctly for Return Water Control (ON) or Supply Water Control (OFF)? If continuous boiler operation is required, is switch #7 in the up (ON) position? If high temperature venting has been installed (CPVC or polypropylene), is switch #8 in the up (ON) position? Front Panel DIP switch setting (DIP SW 1, set of 10) Is switch #2 set correctly for Celsius (ON) or Fahrenheit (OFF)? Is switch #4 and #5 are set correctly for the installation altitude?

  • Page 73: Operating The Boiler

    11. Operating the Boiler 2. Press the + (Up) or – (Down) buttons until the desired 11.1 Turning the Boiler On or Off temperature appears on the display. To turn the boiler on or off, press the Power button for 0.3 seconds. MODE MODE You can adjust the temperature while the display is flashing.

  • Page 74: Viewing Basic Information

    11.2.2 Adjusting the DHW Indirect Supply 11.3 Viewing Basic Information Temperature To view information about the boiler, press the Mode button three To adjust the water temperature: times. “INFO” will appear on the display. 1. Press the Mode button twice. The DHW mode icon turns on. 2.

  • Page 75: Viewing Service Information

    Display Description Display Description Space heating return water Space heating water pressure in PSI temperature (°F) DHW priority time Not Available System supply water temperature (°F) (with optional temperature Not Available sensor) System return water temperature (°F) (with optional temperature Not Available sensor) Outdoor air temperature (°F)
  • Page 76 Display Description Display Description System supply water temperature Blower fan motor target RPM (x 10) (°F) (with optional temperture sensor) System return water temperature Blower fan motor current RPM (x 10) (°F) (with optional temperture sensor) APS target voltage DHW priority time in minutes Current exhaust gas temperature2 APS current voltage (°F)

  • Page 77: Setting The Operation Mode

    11.5 Setting the Operation Mode Display Description 1. On the Front Panel, press and hold the Diagnostics Button for over 5 seconds until “1.PAR” is displayed. DHW pump status Overheating sensing (HTL) status MODE Dual venturi status Low water cut-off (LWCO) status 2.

  • Page 78: Setting The Parameters

    If you enter an incorrect password 10 times or make 11.6 Setting the Parameters Note no inputs 5 minutes, the boiler will return to Normal mode. You can modify parameter settings for boiler operations, such as the space heating and DHW temperature ranges, in different To return to the previous mode, press the Reset operating conditions.
  • Page 79 Setting the Heat Load for the Outdoor Reset Control Mode Setting the Lowest Outdoor Temperature Display Description Display Description Outdoor Reset heat load types 1: Finned tube baseboard Lowest outdoor temperature (°F) 2: FAN coil 3: Cast iron baseboard 4: Low mass radiant 5: High mass radiant 6: Radiator Lowest outdoor temperature not...
  • Page 80 Setting the Pump Freeze Protection Temperature Setting the Boost Interval Time Display Description Display Description Pump freeze protection temperature Boost interval time (min) (°F) This menu is used to configure the circulation pump freeze The boost interval time may be set to prevent interruption in protection temperature.
  • Page 81 Setting the Pump Overrun Time Setting the Burner-On Temperature Differential Display Description Display Description Pump overrun time (min) Burner-on temperature (°F) The pump overrun time is the duration the circulation pump During space heating, the boiler turns on the burner when continues to run between the space heating supply or return the space heating supply temperature is below the burner-on temperature reaching the set point and the burner turning off.
  • Page 82 Setting the Supply Absolute MIN Temperature Setting the Return Absolute MIN Temperature Display Description Display Description Supply absolute Min set point (°F) Return absolute MIN set point (°F) This menu can be used to change the minimum supply This menu can be used to change the minimum return temperature range in Supply Control mode.
  • Page 83 (On) T-T Zone Controller Connection (Off) Use system pump (Yes) Use this menu to operate the boiler with a Navien SmartZone+ Use this menu to set system pump operation for DHW mode. controller connected via a Ready-Link cable. Default: Off...
  • Page 84 Low Burning Time Setting the Warm Weather Shut-down Display Description Display Description Low burning time during initial Warm weather shut-down heating temperature Default: 1 min Default: OFF Range: 1–20 min Range: OFF, 50°F (10°C) – 104°F (40°C) Burning Acceleration Time Display Description Warm weather shutdown ON...

  • Page 85: Resetting The Boiler

    Use this menu to operate the boiler with the Navi-Link Controller If you do not press the Mode button in 10 seconds Note connected via a Ready-Link cable. after setting a new password, the new password is automatically saved and “*.PSC” is displayed on the Default: OFF front panel.

  • Page 86: Appendixes

    WARNING This conversion kit must be installed by a qualified service agency* in accordance with Navien’s instructions and all applicable codes and requirements of the authority having jurisdiction. The information in these instructions must be followed to minimize the risk of fire or explosion or to prevent property damage, personal injury or death.
  • Page 87 7. Remove the PCB assembly. 10. Once the gas inlet pipe is detached from the gas valve, find location B - the connection above the gas valve where it is attached to the fan motor assembly. Carefully remove the four screws by hand using a Phillips screwdriver and pull the gas valve away from the fan assembly to access the gas orifice.
  • Page 88 Inspect the O-ring between the gas valve and gas valve inlet personal injury, death or substantial property damage. adapter whenever they are disassembled. The O-ring must be Navien NHB boilers are shipped ready to fire natural gas in good condition and must be installed. Failure to comply will ONLY.
  • Page 89 Fuel The set screw is located behind the screw-on Note cover. This must be removed first. NHB-055 10.2 10.8 d. Activate multiple zones and set the boiler to operate at 2-stage D. MAX mode (refer to “11.5 Setting the Operation Mode”...
  • Page 90 The set screw is located behind the screw-on cover. Note NAC-N1 -0.04 in ±0.01 in This must be removed first. NHB-055 NAC-L1 -0.03 in ±0.01 in d. At high fire, do not check the offset value and never adjust NAC-N2 -0.04 in ±0.01 in...

  • Page 91: Wiring Diagram

    12.2 Wiring Diagram (Max 8 W, 0.3 A) Appendixes...

  • Page 92: Ladder Diagram

    12.3 Ladder Diagram Appendixes...

  • Page 93: Component Assembly Diagrams And Parts Lists

    12.4 Component Assembly Diagrams and Parts Lists 12.4.1 Case Assembly Appendixes...
  • Page 94 Description Part # Remark 20030085A NHB-110/150 Case 20030088A NHB-055/080 Cover 30013463A 30013044A Front Panel 30013041A Exhaust Pipe Assembly 30008673A Intake Air Duct Assembly 30008662B Intake Air Fillter 20007667A Air Pressure Sensor 30010238A Rubber Ring 20029318A PCB Lower Bracket 20030117A Appendixes...
  • Page 95 12.4.2 Heat Exchanger and Waterway Assembly 23-1 Appendixes...
  • Page 96 Description Part # Remark 30014219A NHB-150 30013575A NHB-110 Heat Exchanger Assembly 30014060A NHB-080 30014218A NHB-055 O-Ring (P29) 20032163A NHB-110/150 O-Ring (Φ17.5x2.7t) 20003022A NHB-055/080 20017724A NHB-110/150 Fastener 20007853A NHB-055/080 High Limit Switch 30002558A 30014032A NHB-110/150 SC Outlet Adapter 30014067A NHB-055/080 Thermistor...
  • Page 97 12.4.3 Combustion Parts Assembly 10-1 10-2 10-3 Appendixes...
  • Page 98 NHB-150 10-3 Intake Pipe 20030064A NHB-110 20031243A NHB-055/080 Orifice Packing 20022660A 20032404A NHB-150 (NG) 20032403A NHB-110 (NG) 20032402A NHB-055/080 (NG) Gas Orifice 20032407A NHB-150 (LP) 20032406A NHB-110 (LP) 20032405A NHB-055/080 (LP) O-Ring (P34) 20019090A 30013955A NHB-150 Gas Pipe 30013509A NHB-110...

  • Page 99: Outdoor Temperature Sensor

    When necessary, shielded cable may be used. Make sure wiring connections are secure before closing the cap. The sensor is a water resistant device. Any damage to the device may require the replacement of the entire component. Navien Outdoor Temperature Sensor Kit Appendixes...

  • Page 100: Outdoor Reset Control

    12.6 Outdoor Reset Control Outdoor Temperature Sensor Installation Guidelines The Outdoor Reset Control feature may be used to enhance energy Supply Set Point Return Set Point efficiency while maintaining optimal heating performance. With Heat Load Range Range the Outdoor Reset Control, the space heating temperature setting automatically changes according to the outdoor temperature and Finned Tube 120-180°F...
  • Page 101 Memo...
  • Page 102 Getting Service If your boiler requires service, you have several options for getting service: Contact Technical Support at 1-800-519-8794 or on the website: www.navien.com. For warranty service, always contact Technical Support first. Contact the technician or professional who installed your boiler.

This manual is also suitable for:

Nhb-080Nhb-150Nhb-110Nhb seriesNhb-55Nhb-80

Table of Contents