Navien NPE-240A Service Manual

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

Navien NPE-240A Specifications

General

Type	Tankless
Fuel Type	Natural Gas or Propane
Energy Factor	0.97
Energy Efficiency	97%
Voltage	120V
Ignition Type	Electronic
Maximum Input	199, 900 BTU/h
Water Connection Size	3/4"
Gas Connection Size	3/4"
Warranty	15-year on heat exchangers, 5-year on parts, 1-year on labor
Dimensions	17.3" W x 13.2" D x 27.4" H