Navien NFC Series, User'S Information Manual

Page: 22 / 26

Troubleshooting 21
5.2 Understanding Error Codes
When an error code appears on the front panel, refer to the following chart for a definition and possible remedy for the situation.
Error Code Reason Self-diagnostic/Action
E001 Heatexchanger over temperature
Manual RESET
Auto RESET
E003 Ignition failure Manual RESET
E004 False flame detection
Manual RESET
Auto RESET
E012 Flame loss Manual RESET
E016 Overheating of heat exchanger Manual RESET
E030 Abnormal exhaust temperature
Manual RESET
Alarm
E031 Overheating of burner Manual RESET
E046 Abnormal operation: limit control Auto RESET
E047 Abnormal operation: exhaust thermostat
Manual RESET
Auto RESET
E060 Abnormal operation: dual venturi Alarm
E109 Abnormal operation: fan motor Manual RESET
E110 Abnormal air pressure Manual RESET
E205 Heating supply thermistor open or short circuit Auto RESET
E218 Heating return thermistor open or short circuit Auto RESET
E278 Abnormal operation: system supply thermistor Alarm
E279 Abnormal operation: system return thermistor Alarm
E351 Abnormal Auto feeder valve (make-up water) Manual RESET
E352 High water pressure Auto RESET
E353 Abnormal operation: water pressure sensor Auto RESET
E407 Hot water outlet: thermistor open or short circuit Auto RESET
E421 Cold water inlet: thermistor open or short circuit Auto RESET
E434 Abnormal operation: water adjustment valve Alarm
E439 Abnormal operation: flow sensor Alarm
E441 Hot water outlet 2: thermistor open or short circuit Auto RESET
E445 Abnormal operation: Bypass mixing valve Alarm
E515 Abnormal operation: PCB
Manual RESET
Alarm
E517 Abnormal operation: Dip switch setting Manual RESET
E594 Abnormal operation: EEPROM Alarm