Navien NP-180 Service Manual page 125

Check method
Error
Gas pressure error
Defective gas
Combustion
stops during pressure sensor
the operation
Defective gas
pressure sensor
Defective
Other trouble
©Navien America Inc. 2010
Cause
Measure the main pressure.
LP : 8"(9" 180 Model) ~13.5" W.C
If the gas pressure is low, contact the gas supplier.
Cause of low gas pressure:
1) Narrow gas pipe.
2) Defective gas regulator.
3) Lack of gas in the container.
4) Clogged pipe (foreign substance)
1. Check if the gas pressure sensor hose is damaged.
2. Check if the gas pressure sensor hose is clogged.
3. Check if the gas venturi is clogged.
hose
1. Check the gas pressure sensor value (AD value) displayed on
the controller. (P.100
Check the value at min / max of the combustion specification table.
2. Check the gas pressure sensor voltage
Operating voltage (Black+Red) : DC 5 V
Sensor output voltage (Black+White) : DC 0.3~4.0 V
If the trouble continues despite the checking of above items,
replace the PCB.
PCB
123
NR/NP series service Manual
Check method
100)
Version 2.0