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6        About the Boiler

2.2    Parts of the Boiler

Front View

Exhaust  

Gas Vent

Combustion  

Air Intake

Bottom View

#

Description

a

Pump Drain Plug

b

Space Heating Strainer

c

Space Heating Supply Connection

d

Space Heating Return Connection

e

DHW Hot Water Outlet Connection

f

Gas Connection

g

Cold Water Inlet Filter

h

Condensate Water Outlet

i

Auto Feeder Connection

j

Cold Water Inlet Connection

2.1    Description of the Boiler

The Navien NCB boiler is available in 3 models: NCB-180, NCB-210, 

and NCB-240.

The main features are as follows:

 

Power Interruption: When the power is restored after a power 

failure, the boiler will automatically start and return to normal 

operation. A manual reset is not required.

 

Automatic Water Fill: Should the water level in the system fall too 

low, a sensor will automatically activate the refill circuit. 

 

Freeze Protection: A sensor inside the boiler automatically 

detects the temperature and, if necessary, initiate a safety 

heating cycle to prevent internal equipment damage due to 

freezing temperatures.

 

Short-Circuit Protection: Any short-circuit occurring in the 

boiler’s electrical circuit immediately blows the internal glass 

fuses and automatically cuts off the gas supply.

 

Lightning Protection: Each boiler is specially grounded, both 

internally and externally, to protect against lightning strikes.

 

Carbon Monoxide Protection: The boiler is designed to maintain 

a safe air-to-gas ratio and combustion rate. This function is 

continuously monitored by the boiler’s air ratio control module.

 

Thermostat Control Failure: Should the thermostat fail to 

function properly, the boiler’s gas supply will be shut off 

automatically as a safeguard.

 

Auto Fan Detection: The rotation of the fan is automatically 

detected and controlled. Fan failure will stop the operation of 

the boiler.

 

Boiling Prevention: Excessive temperatures will automatically 

stop the boiler.

2.    About the Boiler

a

b

c

d

e

f

g

h

i

j

Summary of Contents for NCB-180

Page 1: ...navienamerica com For warranty service always contact Technical Support first Contact the technician or professional who installed your boiler Contact a licensed professional for the affected system f...

Page 2: ...fire or explosion may result causing property damage personal injury or death Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance WHATTO D...

Page 3: ...9 3 3 Viewing Basic Information 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 Cleaning the Inlet Water Filter DHW side 13 4 4 Cle...

Page 4: ...tment C Use only your hand to push in or turn the gas control knob Neverusetools Iftheknobwillnotpushinorturnbyhand don t try to repair it call a qualified service technician Force or attempted repair...

Page 5: ...130 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...

Page 6: ...ler 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 to the appliance WARNING Shut off the gas suppl...

Page 7: ...side the boiler automatically detects the temperature and if necessary initiate a safety heating cycle to prevent internal equipment damage due to freezing temperatures Short Circuit Protection Any sh...

Page 8: ...important information required for the boiler s operation Refer to the following table for detailed information a Space heating mode f S Supply water control Indicates space heating mode operation In...

Page 9: ...t the values required for the boiler 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...

Page 10: ...er settings menu The boiler will retain your settings during a power outage 3 1 Turning the Boiler On or Off To turn the boiler on or off press the Power button for 0 3 seconds MODE When the power is...

Page 11: ...he water temperature read To prevent burns on page 4 carefully Water above 120 F can cause instant scalding severe burns or death To adjust the water temperature 1 Make sure that all hot water faucets...

Page 12: ...to the Troubleshooting section of this manual or contact Technical Support at 1 800 519 8794 Display Description psi O R S R Outdoor reset curve Not in use 1 Finned tube baseboard 2 FAN coil 3 Cast ir...

Page 13: ...Boiler You will need to drain either both the space heating side and domestic hot water DHW side or one side only before performing maintenance tasks such as cleaning the inlet water filter or to pre...

Page 14: ...require draining and open a purge valve to drain the space heating side Open all domestic hot water faucets completely to drain the water heating side The water that remains in the plumbing lines will...

Page 15: ...rinse it with clean running water cold 4 Reinsert and tighten the strainer 5 Fill the boiler and check for proper operation 4 5 Cleaning the Air Intake Filter If the air intake filter becomes clogged...

Page 16: ...rew 10 Replace the front cover 11 Reconnect the power supply to the boiler 12 Press the Power button on the front panel to turn on the boiler 4 Remove the screw that secures the air intake filter the...

Page 17: ...t there is sufficient make up air to avoid such a situation and the owner is responsible for ensuring that protection against freezing is maintained To avoid freezing issues we strongly recommend the...

Page 18: ...e boiler Failure to perform the 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 p...

Page 19: ...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 Remo...

Page 20: ...ignition flame detector electrode making sure gasket is in good condition and correctly positioned Checking the Ignition Ground Wiring 1 Check that the ground wire is in good condition and securely a...

Page 21: ...on the supply and return water lines 4 Connect one tube to the A valve and place the free end in the bucket 5 Connect one of the tubes to the circulation pump outlet and the return water line at the B...

Page 22: ...fer to 3 2 Adjusting the Temperature on page 9 Check for cross plumbing 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 th...

Page 23: ...r open or short circuit Contact Technical Support at 1 800 519 8794 E351 Abnormal Auto feeder valve make up water Contact Technical Support at 1 800 519 8794 E352 High water pressure Contact Technical...

Page 24: ...al and shall be subject to Navien s schedule of approved labor allowances Warranty Exclusions Navien s Limited Warranty shall be void in the event of an occurrence of any of the following Improper ins...

Page 25: ...nited States and Canada Removal or alteration of the rating plate OtherTerms This Limited Warranty is subject further to the terms and conditions set forth herein and as may be further specified in th...

Page 26: ...Memo...

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