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16        Maintaining the Boiler

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

 

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If the system contains glycol, test for proper 
concentration as recommended by manufacturer.

 

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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

 

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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.

 

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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

 

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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.

 

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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. 

 

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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 NHB-110

Page 1: ...nce 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...

Page 2: ...oiler On or Off 8 3 2 Adjusting the Temperature 8 3 3 Viewing Basic Information 9 3 4 Resetting the Boiler 10 4 Maintaining the Boiler 11 4 1 Cleaning the Boiler 11 4 2 Draining the Boiler 11 4 3 Clea...

Page 3: ...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 4: ...shut off turn off the manual gas valve to the appliance WARNING Shut off the gas supply if the boiler is damaged Have your installer or plumber show you the location of the gas shut off valve and dem...

Page 5: ...e temperature and if necessary initiates a safety heating cycle to prevent internal equipment damage due to freezing temperatures Short Circuit Protection Any short circuit occurring in the boiler s e...

Page 6: ...peration Refer to the following table for detailed information a Space heating mode f S Supply water control Indicates space heating mode operation Indicates supply water control status b Error g R Re...

Page 7: ...ler s operation such as space heating and DHW supply temperatures Refer to the following table for detailed information k Diagnostics button n Up button For installers only Increases the temperature l...

Page 8: ...fault space heating return water temperature range is 86 F 30 C Absolute MIN to 149 F 65 C Absolute MAX You can adjust the temperature range in the parameter settings menu The boiler will retain your...

Page 9: ...Low mass radiant 5 High mass radiant 6 Radiator 7 Custom set by installer 3 2 2 Adjusting the DHW Indirect Supply Temperature To adjust the water temperature 1 Press the Mode button twice The DHW mod...

Page 10: ...ooting section of this manual or contact Technical Support at 1 800 519 8794 Display Description psi O R S R Pri Boost interval time set by installer psi O R S R Pri Space heating water pressure in PS...

Page 11: ...e 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 freezin...

Page 12: ...clean the air intake 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 MODE 2 Disconnect the power supply to the boiler 3 Remov...

Page 13: ...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 14: ...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 protection against freezing is maintain...

Page 15: ...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 16: ...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 17: ...r 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 contra...

Page 18: ...inutes d Close the B valve and open the D 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 boiler To flu...

Page 19: ...the system in stand by Make sure the power is on and plugged into the outlet with the correct voltage Press the Power button and raise the setting temperature Make sure the boiler is turned on Is the...

Page 20: ...On reset E205 Abnormal operation heating supply thermistor Auto reset E218 Abnormal operation heating return thermistor Alarm E271 Temperature differential limit Alarm E278 Abnormal operation system...

Page 21: ...uct If the original installer cannot be identified the end user or homeowner may contact Navien s Technical Administration Department at 800 519 8794 Proof of purchase is required to obtain warranty s...

Page 22: ...F NAVIEN HAD OR SHOULD HAVE HAD ANY KNOWLEDGE ACTUAL OR CONSTRUCTIVE OF THE POSSIBILITY OF SUCH DAMAGES Warranty Exclusions Navien s Limited Warranty shall be void in the event of an occurrence of any...

Page 23: ...Memo...

Page 24: ...er Contact 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 num...

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