Navien NP-180 Service Manual page 75

DIP S/W capacity
setting error
Adjust gas
pressure
Flame blowout
and noise occurs
at ignition
Check if there is
any foreign
substance
in the nozzle.
Defective air Defective air
supply
©Navien America Inc. 2010
PCB
Incorrect DIP S/W setting per capacity displayed on the PCB may
cause a problem on ignition and combustion.
Adjust differential pressure to MIN between 3 stages with the gas
manometer.
Turn the adjusting screw under the gas block 1/2 turn and restart.
When an ignition fail occurs due to a problem in supplying gas or
adjusting gas pressure, cover the blower inlet hole with a hand at
the ignition stage. If a flame occurs, check the gas supply system.
< Check the differential gas pressure >
Ignition fail occurs if there is foreign substance in the nozzle.
Disassemble the manifold and check the nozzle (Stage 1).
Check if rainwater is collected due to downward air supply pipe.
supply
73
NR/NP series service Manual
T-connection to GPS +
T-connection to gas block proportional valve
Version 2.0