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User’s Information Manual NCB-H Condensing Combi-Boilers Model NCB-190/060H NCB-190/080H NCB-240/110H NCB-240/130H NCB-250/150H Keep this manual near this boiler for future reference whenever maintenance or service is required. NSF/ANSI 372 * The wetted surface of this product contacted by consumable water contains less than one quarter of one percent (0.25%) of lead by...
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 Accessing Basic Menu Items 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 DANGER this manual precisely to avoid unsafe operating conditions, fire, explosion, property damage, If you do not follow these instructions exactly, personal injury, or death.
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WARNING WARNING Do not touch the power cord or internal ● components of the boiler with wet hands. Doing so may result in electric shock. Do not make any electrical connections ● before turning off the electrical power supply at service entrance panel. Doing so may result in severe personal injury or death.
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CAUTION DANGER 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, maintenance may lead to property damage, personal injury, or death and will void your BURN warranty.
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DANGER This boiler’s DHW temperature is set to 120°F (49°C) at the factory for your safety and comfort. Increasing the temperature increases the risk of accidental scalding. Water temperatures at or above 125°F (52°C) can cause instant scalding, severe burns, or death. Before you decide to change the temperature setting, read the following charts carefully.
2. About the Boiler 2.1 Description of the Boiler 2.2 Parts of the Boiler The Navien NCB-H boiler is available in 5 models: NCB-190/060H, NCB-190/080H, NCB-240/110H, 2.2.1 Front View NCB-240/130H and NCB-250/150H. The main features are as follows: Combustion Exhaust Power Interruption: When the power is restored ●...
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 and Command Dial Using the buttons and the Command dial ( ) 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.
3. Operating the Boiler 3.2 Adjusting the Temperature WARNING Follow the instructions below to avoid unsafe 3.2.1 Adjusting the Space Heating operating conditions that could cause property Temperature damage, severe personal injury, or death. To adjust the heating temperature: Ensure that the boiler is filled with water ●...
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You can adjust the temperature while the 2. Rotate the Command dial ( ) to the right to highlighted section is flashing. Once the flashing select the DHW temperature ( stops, the current temperature setting is stored. The space heating temperature Note ●...
3.3 Accessing Basic Menu Items Item Description AHU Space Heating Set In the Main Menu screen, you can view the boiler’s Temperature (°F) operating conditions, configure the space heating and DHW temperatures, and review error history. If AHU is not connected, ●...
3.4 Resetting the Boiler Item Description 22. Flow Control If an error message appears during boiler operation, 100 - Close State Valve Status clear the message and resolve the problem. Press the Back button ( ) on the front panel to reset the 23.
4. Maintaining the Boiler 4.1 Cleaning the Boiler 3. Close the gas valve. 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 Open Closed...
4.3 Cleaning the Domestic Cold 5. Remove the drain cap on the manifold system to drain the boiler. Filter (DHW side) To clean the filter: 1. Drain the DHW side of the boiler. Refer to “4.2 Draining the Boiler” on page 14. 2.
4.4 Cleaning the Heating Return 4.5 Cleaning the Air Intake Filter Water Filter (Space Heating side) If the air intake filter becomes clogged by dust or lint, the boiler will cease to operate and “Error If the heating performance is decreased, you can Code 110”...
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4. Remove the screw that secures the air intake 6. Remove the filter from the plastic assembly. filter (the filter is located at the top left of the Dust and rinse it with clean running water. boiler). 7. Allow the filter to dry completely. 8.
This is not a manufacturing CAUTION defect, and therefore, Navien will not warrant any damages due to freezing. The If the unit will not be used immediately, close off installer is responsible for ensuring that...
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Service technician (See the following instructions) WARNING General: Follow service maintenance ● Address reported problems. ● procedures given throughout this manual Inspect interior; clean and ● and in component literature shipped with vacuum if necessary. the boiler. Failure to perform the service and Clean condensate trap and fill maintenance could result in damage to the ●...
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Inspecting the Boiler Interior Checking the Water System 1. Remove the front cover and inspect the interior 1. Verify all system components are correctly of the boiler. installed and operational. 2. Vacuum any sediment from inside the boiler 2. Check the cold fill pressure for the system. Verify and components.
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Inspecting the Ignition and Flame Safety relief valves should be inspected Note at least once every three years, by Detector Electrodes a licensed plumbing contractor or authorized inspection agency, to ensure 1. Remove the ignition and flame detector that the product has not been affected electrodes from the boiler heat exchanger.
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A water circulation pump ● 2 flush valves (if not installed) ● Before flushing the heat exchanger, Note additional flush valves (“A” and “B”) must be installed on the near boiler piping (included with Navien Manifold System). Maintaining the Boiler...
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7. Pour the cleaning solution into the bucket. 8. Open both “A” and “B” valves. 9. Turn on the circulation pump and allow the solution to circulate through the boiler. Refer Navien Manifold to the manufacturer’s literature for information System about the circulation time.
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.
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 Manual RESET E001 Heatexchanger over temperature Auto RESET E003 Ignition failure Manual RESET Manual RESET...
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Error Code Reason Self-diagnostic/Action Manual RESET E615 Abnormal operation: input and memory Auto RESET Alarm E736 Abnormal operation: cascade communication Alarm Abnormal operation: outdoor temperature sensor (appears E740 Alarm only when the outdoor reset curve is enabled). E761 Abnormal Operation: Pre-Heat Aquastat Alarm E762 Abnormal flue gas duct: Vent pipe not properly inserted...
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The request, proof of the original installation date must replacement component must be Navien original also be provided to Navien. When the product is factory component. Navien, at its sole discretion, installed in a new construction, the commencement...
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Installer’s failure to fully comply with the warranty the product. NAVIEN SHALL NOT IN ANY EVENT BE ● service and return policy procedures previously LIABLE FOR INDIRECT, SPECIAL, CONSEQUENTIAL provided to installer and as is available on OR LIQUIDATED DAMAGES OR PENALTIES, Navien’s website.
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Installation location and type ● Error code, if any appears on the front panel display. ● Version: 1.0 (November, 2020) Navien, Inc. 800.519.8794 www.navieninc.com 20 Goodyear, Irvine, CA 92618 T H E L E A D E R C O N D E N S I N G...
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