352Error - Navien NCB-150E Service Manual

5.2.15 352Error

Error conditions and Check Items
Error
E352
High water pressure
Check items
Check method
Fault
E352
High water pressure
sensor
118 NCB-E Service Manual
Upon receiving a signal from the water pressure sensor, the system displays the error(E352) on
front panel.
High water level error if the water level of 56.6 psi or higher continues 3 seconds.
Error is automatically cancelled if water level is 43.5 psi or lower.
1. Check if the cold water pipe input water pressure sensor is wet due to any reason, including
leakage.
2. Check the Auto Feeder Sensor.
3. Check the controller.
Leaking in unit
No
Is the water
pressure sensor
normal?
Yes
1. Check connecter
(#1,#2 and #3 of CN 22)
Possible Causes
Check the pressure increase conditions. (high water pressure of 3.9bar or higher)
High water pressure Check if the safety valve is stuck.
Check if Auto feeder valve is normal.
1. Check the output voltage. (Normal state : 0.3-2.8V)
Defective water pressure
sensor
2. Replace the defective or opened water pressure sensor.
Defective Auto Feeder
1. Check the Auto feeder valve. (refer to page80)
valve
Description
Yes
Check leaking in unit
No
Replace the water pressure sensor
Check method
Version 1.4