Navien NP-180 Service Manual page 101

Check method
Error type
Connector
contact error
Defective
sensor
Defective air
volume sensor
Defective
Other trouble
©Navien America Inc. 2010
Cause
Check connector assembly and contact of the air volume sensor.
1. Check the air volume sensor value displayed on the PCB.
(AD value) (A.150
Check the value at min / max of the combustion specification table.
Replace the air pressure sensor if an error occurs
(standard value ±500 or higher).
2. Check the air volume sensor voltage.
Operating voltage (Black+Red) : DC 5 V
Sensor output voltage (Black+White) Open: DC 0.1±0.1 V or lower
Short circuit: DC 4.5±0.2 V or higher
An error occurs if the air volume sensor voltage of 1.20V is
detected before pre-purge.
If the trouble continues despite the checking of above items,
replace the PCB.
PCB
NR/NP series service Manual
Check method
150)
99
Version 2.0