Page 1
User’s Information Manual NFC Condensing Combi-Boilers 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. ●...
Page 2
User’s Information Manual NFC Condensing Combi-Boilers Model NFC-175 NFC-200 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 weight.
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 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.
Page 5
California law requires the following Prop 65 warning to be provided: WARNING WARNING This product can expose you to chemicals including lead, lead compounds, and carbon bisulfide which are known to the State of California to cause cancer and birth defects or other reproductive harm.
Page 6
DANGER DANGER This boiler’s DHW water 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.
2. About the Boiler 2.1 Description of the Boiler 2.2 Parts of the Boiler The Navien NFC boiler is available in 2 models: NFC-175 and NFC-200. 2.2.1 Front View The main features are as follows: 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.
Page 9
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 3.1 Turning the Boiler On or Off 2. Press the Command dial ( ) to select the space heating temperature ( ). The highlighted section will flash. To turn the boiler on or off, press the Power button. 3.
3.2.2 Adjusting the DHW Indirect Supply 6. Press the Back button ( ) to return to normal operation Temperature mode, or rotate the Command dial ( ) to adjust other operation conditions. To adjust the water temperature: You can adjust the temperature while the display is flashing. Once the display stops flashing, the current temperature setting is 1.
Item Description Item Description 1. Operation State Current Operation State Outdoor Reset Curve Load Type (Displayed when the outdoor reset 2. Heat Capacity Heat Capacity (%) option “20. Outdoor Reset”is enabled.) 1: Finned Tude Baseboard 3. SH Set Temp Space Heating Set Temperature (°F) 25.
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 cleaning.
4.3 Cleaning the Air Intake Filter 5. Remove the drain cap on the manifold system to drain the 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.
Page 15
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.
4.5 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 ●...
Page 17
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.
Page 18
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.
Page 19
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.
Page 20
10. Rinse the cleaning solution from the boiler: a. Remove the free end of the drain tube from the bucket and place it in the condensate drain or laundry tub (wherever Navien the boiler drains). Manifold System b.
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 Back 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 Manual RESET E001 Heatexchanger over temperature Auto RESET E003 Ignition failure Manual RESET Manual RESET...
Page 23
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 only when the E740 Alarm outdoor reset curve is enabled). E761 Abnormal Operation: Pre-Heat Aquastat Alarm E777 LWCO (service code: 7700) (external device)
Page 24
You must contact the original installer of your Product. Your Subject to the foregoing terms, Navien will repair or replace the installer will need to contact Navien to report the issue. If the covered Product or any part or component that is defective in...
Page 25
What is not covered? Warranty Limitations Navien’s Limited Warranty shall be void in the event of an EXCEPT AS EXPRESSLY PROVIDED HEREIN, THERE ARE NO OTHER occurrence of any of the following: WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO WARRANTIES OR MERCHANTABILITY OR FITNESS FOR A Improper installation, including but not limited to, installation in ●...