Navien NCB500-2S/37K User Manual

Troubleshooting 83
5.2.15 Error 353
Error conditions and checklist
Error Description
E353
Water pressure sensor fault
If a voltage error (< 0.3 V or > 5 V) at the water pressure sensor is detected continuously for
3 sec, the system displays E353. When this error occurs, the boiler shuts down.
Checklist
1. Check if the input water pressure sensor is wet due to any reason, including leakage.
2. Replace the water pressure sensor.
3. Check the controller.
Is there a leak inside
the boiler?
Is the water
pressure sensor
normal?
1. Check connections
Repair the leak in the boiler
Replace the water pressure sensor
Yes
No
Yes
No
Testing method
Fault Possible causes Testing method
Water pressure sensor
fault
Water pressure sensor
fault
1. Check if the sensor is frozen.
2. Check the output voltage. (Normal state: 0.25-4.93 V)
3. Replace the PCB if the voltage is not correct.

Navien NCB500-2S/37K Specifications

General

Brand	Navien
Model	NCB500-2S/37K
Category	Boiler
Language	English