Navien NPN-160U, User'S Information Manual

Page: 22 / 28

22 Troubleshooting
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
E003 Ignition failure
Ɣ
Ensure that the main gas supply valve is open.
Ɣ
Ensure that the gas manifold and the fuel DIP
SW setting match the supplied gas type.
E004 False flame detection
Ɣ
Ensure that the electrical cord is properly
grounded.
E012 Flame loss
Ɣ
Clean the intake air filter. See page 19.
Ɣ
Ensure that the electrical cord is properly
grounded.
Ɣ
Ensure that the gas manifold and the fuel DIP
SW setting match the supplied gas type.
E016 Overheating of heat exchanger
Ɣ
Turn off the system for at least 30 minutes, and
then restart it.
Ɣ
Clean the cold water inlet filter. See page 19.
Ɣ
Flush the heat exchanger. See page 17.
E046 Abnormal operation: limit control Contact Technical Support at 1-800-519-8794.
E056 Abnormal operation: Modulating gas valve Contact Technical Support at 1-800-519-8794.
E109 Abnormal operation: fan motor Contact Technical Support at 1-800-519-8794.
E110 Abnormal air pressure Ensure that the vent pipe is free of obstructions.
E127
Abnormal operation : Air volume Open/
Short/Default value/No answer
Contact Technical Support at 1-800-519-8794.
E157 Abnormal operation : Air volume control Contact Technical Support at 1-800-519-8794.
E170 Antifreeze heater Open/Short Contact Technical Support at 1-800-519-8794.
E407
Hot water outlet: thermistor open or short
circuit
Contact Technical Support at 1-800-519-8794.
E421
Cold water inlet1: thermistor open or short
circuit
Contact Technical Support at 1-800-519-8794.
E434 Abnormal operation: water adjustment valve Contact Technical Support at 1-800-519-8794.
E438 Abnormal operation: circulation pump
External: Ensure that all water supply and return
lines are open.
E439 Abnormal operation: flow sensor Contact Technical Support at 1-800-519-8794.
E441
Hot water inlet2: thermistor open or short
circuit
Contact Technical Support at 1-800-519-8794.
E445 Abnormal operation: Bypass mixing valve Contact Technical Support at 1-800-519-8794.
E515 Abnormal operation: PCB
Ensure that the electrical cord is properly
grounded.