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Maintaining the Boiler        17

Checking the Water System

1.  Verify all system components are correctly installed and 

operational.

2.  Check the cold fill pressure for the system. Verify it is correct 

(must be a minimum of 12 psi).

3.  Watch the system pressure as the boiler heats up (during 

testing) to ensure pressure does not rise too high.

Note

 

If the system contains glycol, test for proper 

concentration as recommended by manufacturer.

 

Excessive pressure rise indicates expansion tank 

sizing or performance problem.

4.  Inspect automatic air vents and air separators. Remove air vent 

caps and briefly press push valve to flush vent.

5.  Replace caps. Make sure vents do not leak. Replace any leaking 

vents.

Checking Expansion Tank

 

Expansion tanks provide space for water to move in and out as 

the heating system water expands due to temperature increase 

or contracts as the water cools.

 

Perform annual checks as recommended by manufacturer to 

ensure proper operation.

Checking the Pressure Relief Valves

1.  Inspect the relief valve and lift the lever to verify flow. Before 

operating any relief valve, ensure that it is piped with its 

discharge in a safe area to avoid severe scald potential.

Note

Safety relief valves should be inspected 

at least once 

every three years

, by a licensed plumbing contractor 

or authorized inspection agency, to ensure that the 

product has not been affected by corrosive water 

conditions and to ensure that the valve and discharge 

line have not been altered or tampered with illegally.

WARNING

 

Certain naturally occurring conditions may corrode the 

valve or its components over time, rendering the valve 

inoperative. Such conditions are not detectable unless 

the valve and its components are physically removed and 

inspected. This inspection must only be conducted by a 

plumbing contractor or authorized inspection agency – not 

by the owner. Failure to re-inspect the boiler relief valve 

as directed could result in unsafe pressure buildup, which 

can result in severe personal injury, death, or substantial 

property damage.

 

Following installation, the valve lever must be operated 

at 

least once a year

 to ensure that waterways are clear. Certain 

naturally occurring mineral deposits may adhere to the valve, 

rendering it inoperative. When manually operating the lever, 

water will discharge and precautions must be taken to avoid 

contact with hot water and to avoid water damage. 

 

Before operating lever, check to see that a discharge line 

is connected to this valve directing the flow of hot water 

from the valve to a proper place of disposal. Otherwise 

severe personal injury may result. If no water flows, valve is 

inoperative. Shut down the boiler until a new relief valve has 

been installed.

2.  After following the above warning directions, if the relief 

valve weeps or will not seat properly, replace the relief valve. 

Ensure that the reason for relief valve weeping is the valve and 

not over-pressurization of the system due to expansion tank 

waterlogging or undersizing.

Inspecting the Ignition and Flame Detector Electrodes

1.  Remove the ignition and flame detector electrodes from the 

boiler heat exchanger.

2.  Remove any deposits accumulated on the ignition/flame 

detector electrode. If the electrodes cannot be cleaned 

satisfactorily, replace with new ones.

3.  Replace ignition/flame detector electrode, making sure gasket 

is in good condition and correctly positioned.

Summary of Contents for NFC Series

Page 1: ...ontact a licensed professional for the affected system for example a plumber or electrician When you contact Technical Support please have the following information at hand Model number Serial number...

Page 2: ...ilding 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...

Page 3: ...iler On or Off 9 3 2 Adjusting the Temperature 9 3 3 Accessing Basic Menu Items 10 3 4 Resetting the Boiler 11 4 Maintaining the Boiler 12 4 1 Cleaning the Boiler 12 4 2 Draining the Boiler 12 4 3 Cle...

Page 4: ...pplier call the fire department Do not return to your home until authorized by your gas supplier or the fire department C Do not use this appliance if any part has been under water Immediately call a...

Page 5: ...for use in the USA and Canada only Using the boiler in any other country will void the manufacturer s warranty Should overheating occur or the gas supply fail to shut off turn off the manual gas valve...

Page 6: ...0 F 55 C 10 seconds 120 F 49 C 10 minutes 100 F 37 C very low scald risk DANGER HOT BURN To prevent burns Use the lowest operating temperature setting necessary to provide comfortably hot water If you...

Page 7: ...eze Protection A sensor inside the boiler automatically detects the temperature and if necessary initiates a safety heating cycle to prevent internal equipment damage due to freezing temperatures Shor...

Page 8: ...when the boiler is operating in anti freeze mode Auto air purge Displayed when an auto air purge is being performed e Cascade Main mode Flashes when configuring a cascade system Turns on solid if the...

Page 9: ...for the boiler s operation such as space heating and DHW supply temperatures Refer to the following table for detailed information a Back button Return to the previous menu or screen b Mode button En...

Page 10: ...ion the boiler will operate at this set temperature Take note of the original heating temperature in case you want to restore it to the default The default space heating supply water temperature range...

Page 11: ...configure the space heating and DHW temperatures and review error history Press the Menu button to enter the Main Menu screen To view information about the boiler press the Menu button and then select...

Page 12: ...or contact Technical Support at 1 800 519 8794 Item Description 1 Operation State Current Operation State 2 Heat Capacity Heat Capacity 3 SH Set Temp Space Heating Set Temperature F 4 DHW Set Temp DH...

Page 13: ...ture resistant but it is not waterproof Keep it as dry as possible 4 2 Draining the Boiler You will need to drain the boiler before performing maintenance tasks such as to prevent the boiler from free...

Page 14: ...e filter every 3 4 months To clean the air intake filter 1 Press the Power button on the front panel to turn off the boiler 2 Disconnect the power supply to the boiler 3 Unfasten the 4 latches 2 at th...

Page 15: ...of the boiler 6 Remove the filter from the plastic assembly Dust and rinse it with clean running water 7 Allow the filter to dry completely 8 Place the filter assembly back into the boiler and secure...

Page 16: ...enwillnotwarrant any damages due to freezing The installer is responsible for ensuring that there is sufficient make up air to avoid such a situation and the owner is responsible for ensuring that pro...

Page 17: ...e service and maintenance could result in damage to the boiler or system Failure to follow the directions in this manual and component literature could result in severe personal injury death or substa...

Page 18: ...ts over time rendering the valve inoperative Such conditions are not detectable unless the valve and its components are physically removed and inspected This inspection must only be conducted by a plu...

Page 19: ...filter is clean Review with the Owner 1 Review the User s Information Manual with the owner 2 Emphasize the need to perform the maintenance schedule 3 Remind the owner of the need to call a licensed c...

Page 20: ...r for 5 minutes d Close the A valve and open the C valve 11 Disconnect all tubes and valves 12 Reconnect the power supply to the boiler 13 Press the Power button on the front panel to turn on the boil...

Page 21: ...er to 3 2 Adjusting the Temperature on page 9 Check for cross piping between the cold and hot water lines The water from the hot water faucet is too hot Is the set temperature set too high Check the b...

Page 22: ...Manual RESET E110 Abnormal air pressure Manual RESET E205 Heating supply thermistor open or short circuit Auto RESET E218 Heating return thermistor open or short circuit Auto RESET E278 Abnormal oper...

Page 23: ...ration outdoor temperature sensor appears only when the outdoor reset curve is enabled Alarm E761 Abnormal Operation Pre Heat Aquastat Alarm E777 LWCO service code 7700 external device Auto RESET E782...

Page 24: ...riod replacement of the Product or components may be authorized by Navien only Navien does not authorize any person or company to assume for it any obligation or liability in connection with the repla...

Page 25: ...tion for non recommended uses failure to follow or comply with the User s Operational Manual etc Improper maintenance including but not limited to scale buildup vent blockage failure to maintain etc M...

Page 26: ...Memo...

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