Navien NPE-180A Service Manual page 75

Sub
Error Code
Code
1 Abnormal Hot water outlet thermistor (Open)
E407
2 Abnormal Hot water outlet thermistor (Short)
1 Abnormal Cold water inlet thermistor (Open)
E421
2 Abnormal Cold water inlet thermistor (Short)
1 Abnormal Cold water inlet2: thermistor (Open)
E432
2 Abnormal Cold water inlet2: thermistor (Short)
1 Abnormal water adjustment valve. (Open)
E434
2 Abnormal water adjustment valve. (Close)
E438 0 Abnormal circulation pump. ("A" models only)
E439 0 Abnormal flow sensor
1 Abnormal Hot water inlet2: thermistor(Open)
E441
2 Abnormal Hot water inlet2: thermistor(Short)
1 Abnormal mixing valve(Open)
E445
2 Abnormal mixing valve(Close)
1~7 Abnormal communicatin between PCB and Ignitor.
Abnormal communication between PCB and
8
Ignitor
9 Abnormal communication between PCB and FAN
E515
10 Abnormal monitoring device of PCB
Abnormal communication between PCB and Dual
11~12
Venturi
E517 0 Abnormal dip switch setting
E593 1 Abnormal panel key
Abnormal input data from High limit switch of Heat
0
exchanger
1 Abnormal input data from exhaust sensor
E594
2 Abnormal input data from flame rod
3~14 Abnormal memory of PCB
15 Below the range of input data from Pressure sensor
16 Over the range of input data from Pressure sensor
74 NPE Service Manual
Function Self-diagnostic/Action
Check the thermistor.
●
Replace the thermistor.
●
Check the thermistor.
●
Verify [C] value in DIAGNOSTIC mode.
●
Replace the thermistor.
●
Check the thermistor.
●
Check thermistor voltage and resistance values.
●
Replace the thermistor.
●
Check the water adjustment valve.
●
Check the circulation pump.
●
Check water filter for blockage.
●
Check the flow sensor.
●
Check the cold water main line.
●
Set to Internal Recirculation mode and verify flow rate.
●
Check the flow sensor.
●
Check the thermistor.
●
Replace the thermistor.
●
Check the mixing valve.
●
Check the PCB.
●
Check the PCB connection.
●
Check the Ignitor.
●
Check the PCB connection.
●
Check the Fan.
●
Check the PCB connection.
●
Check the Dual Venturi.
●
Check the PCB connection.
●
Check the Dual Venturi.
●
Check the dip switches on the front panel and PCB.
●
Check the Panel.
●
Check the PCB.
●
Check the exhaust sensor wiring connection.
●
Check the exhaust sensor.
●
Check the flame rod wiring connection.
●
Check the flame rod.
●
Check the PCB
●
Check the Pressure sensor wiring connection.
●
Check the output voltage of pressure sensor.
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Version 2.21