38Error - Navien NP-180 Service Manual

5.22. 38Error

Error occurrence conditions and check items.
Error
Connect the power, start the pump, and check if the system senses the flow.
38E
If the flow is not sensed after the pump is started, the system displays 38E
Pump error
(cleared automatically) on the remote controller and the PCB.
1. Defective flow sensor.
2. Defective pump.
Check items
3. Defective PCB.
Is there clod water supply
inside water heater?
Yes
Circulation PUMP normal
operating?
Yes
Check water flow sensor
©Navien America Inc. 2010
Description
Supply cold water for water
No
heater inside
PUMP output voltage
No
normal?
Yes
Replace PCB
Or check connector
112
NR/NP series service Manual
No Replace circulation PUMP
Check the voltage of CN13:
Over 97V AC
Version 2.0