Navien NHB-055, Service Manual

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78 NHB Service Manual Version 1.0
5.1 Error code classification
Classification Error Code Error Level Function Self-diagnostic / Action
Combustion System
E001
3
2
Overheating of Heat Exchanger
Manual RESET
Auto RESET
E003 3 Ignition failure Manual RESET
E004 2 False flame detection Auto RESET
E012 3 Flame loss Manual RESET
E016 3 Overheating of heat exchanger Manual RESET
E030
3
1
Exhaust Overheat: exhaust limit switch shuts
down the unit when the flue temperature
exceeds 230°F(110°C) for more than 10
seconds.
Manual RESET
Alarm
E046 2 Abnormal heat exchanger thermistor Auto RESET
E047
3
2
Abnormal exhaust thermistor
Manual RESET
Auto RESET
E060 1 Abnormal Dual Venturi Limit Switch Auto RESET
Air supply System
E109 3 Abnormal FAN motor activity Manual RESET
E110 3 Exhaust blockage Manual RESET
- -
Abnormal APS (open, short, initial value or no
answer)
No error display
CH System
E205 2
Abnormal H / E outlet : thermistor open or
short
Auto RESET
E218 1 Abnormal H / E inlet : thermistor open or short Alarm
E271 1 Temperature differential limit Alarm
E278 1 Abnormal system supply thermistor Alarm
E279 1 Abnormal system return thermistor Alarm
E291 3 Supply / Return inversion limit Manual RESET
Water supply System
E302 3 Abnormal water pressure (Low pressure) Manual RESET
E352 2 Abnormal water pressure (High pressure) Auto Reset
E353 2 Abnormal water pressure sensor Auto Reset
Controller
E515 3 Abnormal PCB Manual RESET
E517 3 Abnormal DIP Switch setting Manual RESET
E594 1 Abnormal communication in parts of PCB Alarm
E615 3 Abnormal input & memory Manual RESET
Installation System
E740 1 Abnormal outdoor sensor Alarm
E777 2 Abnormal LWCO Auto RESET
E782 1 Abnormal Main-Panel communication Alarm
E784 1 Abnormal Zone controller communication Alarm
5. Troubleshooting