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NHB Condensing Boiler User’s Information Manual 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.
Contents 1. Safety Information 2. About the Boiler 2.1 Description of the Boiler 2.2 Parts of the Boiler 2.3 The Front Panel 3. Operating the Boiler 3.1 Turning the Boiler On or Off 3.2 Adjusting the Temperature 3.3 Viewing Basic Information 3.4 Resetting the Boiler 4.
1. Safety Information The following safety symbols are used in this manual. Read and follow all safety instructions in this manual precisely to avoid WARNING unsafe operating conditions, fire, explosion, property damage, personal injury, or death. Keep this manual for future reference. If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life.
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CAUTION WARNING Do not attempt to repair or replace any part of the boiler, unless it is specifically recommended in this manual. For all other service, contact an authorized technician or licensed professional. Improper adjustments, alterations, service, or maintenance may lead to property damage, personal injury, or death and will void your warranty.
2. About the Boiler 2.1 Description of the Boiler 2.2 Parts of the Boiler The Navien NHB boiler is available in 4 models: NHB-055, NHB-080, NHB-110 and NHB-150. 2.2.1 Front View The main features are as follows: Combustion Power Interruption: When the power is restored after a power...
2.3 The Front Panel The front panel allows you to adjust the temperature and view the operating status or error codes. Remove the protective sheet from the front panel before using it. 2.3.1 Icons and Digital Display The icons and digital display on the front panel provide important information required for the boiler’s operation.
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2.3.2 Buttons Using the buttons on the front panel, you can turn on or off the boiler, monitor the current operation status, and set the values required for the boiler’s operation, such as space heating and DHW supply temperatures. Refer to the following table for detailed information.
3. Operating the Boiler 2. Press the + (Up) or – (Down) buttons until the desired 3.1 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. You can adjust the temperature while the display is flashing.
3.2.2 Adjusting the DHW Indirect Supply 3.3 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.
3.4 Resetting the Boiler Display Description If an error message appears, you can try resetting the boiler to resolve the problem. To reset the boiler, press the Reset button. Boost interval time (set by installer) Space heating water pressure in PSI DHW priority time System supply water temperature (°F) (with optional temperature...
4. Maintaining the Boiler 3. Close the gas valve. 4.1 Cleaning the Boiler CAUTION Make sure the boiler is turned off and the power supply is disconnected before cleaning the boiler. The boiler may remain hot for several minutes after it is turned off. To prevent burns, wait until the boiler has cooled down before cleaning.
5. Remove the drain cap on the manifold system to drain the 4.3 Cleaning the Air Intake Filter boiler. If the air intake filter becomes clogged by dust or lint, the boiler will cease to operate and “Error Code 110” will appear on the front panel display.
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4. Remove the screw that secures the air intake filter (the filter is 6. Remove the filter from the plastic assembly. Dust and rinse it located at the top left of the boiler). with clean running water. 7. Allow the filter to dry completely. 8.
4.4 Protecting the Boiler from Freezing 4.5 Maintenance Schedules Owner maintenance CAUTION Check the boiler area is free of Damage due to freezing is not covered by the Navien limited combustible/flammable materials and warranty. air contaminants. Daily Freezing damage is most likely to occur due to back drafting Check the pressure/temperature caused by negative pressure in the building.
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Cleaning the Condensate Trap WARNING 1. Inspect the condensate drain line, condensate fittings, and condensate trap. Follow the service and maintenance procedures given throughout this manual and in component literature 2. Remove any sediment in the trap. shipped with the boiler. Failure to perform the service and maintenance could result in damage to the boiler or system.
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Checking the Water System WARNING 1. Verify all system components are correctly installed and operational. Certain naturally occurring conditions may corrode the valve or its components over time, rendering the valve 2. Check the cold fill pressure for the system. Verify it is correct inoperative.
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1. Start boiler and make sure that the boiler is operating properly. valves (“A” and “B”) must be installed on the near boiler piping (included with Navien Manifold System). 2. Verify cold fill pressure is correct and that operating pressure does not go too high.
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Refer to the manufacturer’s literature for information about the circulation time. 10. Rinse the cleaning solution from the boiler: Navien Manifold a. Remove the free end of the drain tube from the bucket and System place it in the condensate drain or laundry tub (wherever the boiler drains).
5. Troubleshooting 5.1 Solving Basic Problems If you experience a problem with the boiler, refer to the following chart for possible remedies. Error codes that appear on the front panel display are explained in the following section. For minor problems, resetting the boiler may resolve the issue. To reset the boiler, press the Reset button on the front panel.
5.2 Understanding Error Codes When an error code appears on the front panel, refer to the following chart for a definition and possible remedy for the situation. Error Code Reason Self-diagnostic/Action E001 Heat exchanger over temperature Auto reset/Manual reset/Power On reset E003 Ignition failure Manual reset/Power On reset...
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To obtain warranty repair service, the end user or homeowner parts and the heat exchanger. The following warranty periods must contact the original installer of your Navien product. If the begin to run from the date of original installation. The date of...
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NAVIEN SHALL NOT IN ANY EVENT BE LIABLE FOR INDIRECT, SPECIAL, CONSEQUENTIAL OR Performance problems caused by improper sizing of the boiler,...
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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.