Navien NP-180 Service Manual page 115

Check method
Error type
Defective flow
Malfunction
Defective pump
Defective
pump
Defective
Other trouble
©Navien America Inc. 2010
Cause
Check the current flow displayed on the PCB (15.66 15.66 gal/min).
The flow sensor is defective if the water flow displayed is 00.0
sensor
when water is discharged from the hot water tap.
< Water leak sensor wire: Blue 2P>
1. Check if the pump works normally.
2. Check the pump power cable connector and if the wiring is
performed normally.
3. Check the power supply (AC 102~132 V).
4. Check for air in the system.
< Circulation pump >
If the trouble continues despite the checking of above items,
the PCB is defective.
PCB
113
NR/NP series service Manual
Check method
< Circulation pump wire: Blue 2P >
Version 2.0