Navien NHB-055, Руководство по обслуживанию

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NHB Service Manual 81 Version 1.0
Error Code Sub Code Function Self-diagnostic / Action
E279
1
Abnormal operation: system return thermistor
(open)
Check the thermistor.
2
Abnormal operation: system return thermistor
(short)
Check the thermistor.
E291 0 Supply / Return inversion limit
Check if the supply water outlet piping of heating
piping and return inlet piping are mutually changed.
E302 0 Low water pressure
Check incoming water pressure and any activity at
PRV.
E352 0 High water pressure
Check incoming water pressure and any activity at
PRV.
E353
1 Abnormal water pressure sensor (Open)
Check the water pressure sensor.
2 Abnormal water pressure sensor (Short)
E515
1-7 Abnormal internal communication of PCB Check the PCB
8 Abnormal communication between PCB and Igniter
1. Check the PCB connection
2. Check the Igniter
9 Abnormal communication between PCB and FAN
1. Check the PCB connection
2. Check the Fan
10 Abnormal monitoring device of PCB 1. Check the PCB connection
11-12
Abnormal communication between PCB and Dual
Venturi
1. Check the PCB connection
2. Check the Dual Venturi
E517 0 Abnormal dip switch setting Check the dip switches on the front panel and PCB.
E594 0 Abnormal operation: EEPROM Check the PCB.
E615
1
Abnormal input data from High limit switch of Heat
exchanger l
Check the PCB.
3 Abnormal input data from flame rod
1. Check the flame rod wiring connection.
2. Check the flame rod.
4-5 Abnormal memory of PCB Check the PCB
E740
1
Abnormal outdoor temperature sensor (Open)
(appears only when the outdoor reset curve is
enabled).
1. Ensure that the outdoor reset curve is configured
properly.
2. Check the outdoor temperature sensor wiring
connection.
2
Abnormal outdoor temperature sensor (Short)
(appears only when the outdoor reset curve is
enabled).