Navien NCB-180, Service Manual, Page: 81 / 149

78 NCB Service Manual Version 1.0
5.2 Error Code List
Error Code Function Self-diagnostic/Action
E003
Ignition failure
1.
Check to see if the main gas supply valve is open.
2. Check that the power is
“
ON
”
.
3. Check the igniter for spark.
4. Tighten the ground connection screws on heat exchanger.
E004
False flame detection
1. Ensure ground wire is connected.
2. Check the igniter for spark.
E012
Flame loss
1. Check the main gas line (Is the valve open?).
2. Check intake air filter.
3. Check ground wire.
4. Check power supply.
5. Tighten the ground connection screws on heat exchanger.
E016
Overheating of heat exchanger
1. Turn OFF the system for at least 30 minutes then restart.
2. Clean the inlet water filter.
3. Check the high limit switch
4. Check the water adjustment valve.
5. Check the heat exchanger; a flush may be necessary.
E030
Exhaust Overheat: exhaust limit switch
shuts down the unit when the flue
temperature exceeds 230
°
F (110
°
C) for more
than 10 minutes.
1. Turn OFF the system for at least 30 minutes then restart.
2. Clean the inlet water filter.
3. Check the water adjustment valve.
4. Check the heat exchanger; a flush may be necessary.
E046
Abnormal heat exchanger thermistor Check heat exchanger thermistor connection
E047
Abnormal exhaust thermistor Check exhaust thermistor connection.
E060
Abnormal operation: dual venturi Check the Dual Venturi connection.
E109
Abnormal fan motor activity
1. Check and clean the intake air filter.
2. Check and clean the fan motor.
E110
Exhaust blockage
1. Check the exhaust pipe for obstructions.
2. Check and clean the intake air filter
E205
Heating supply : thermistor open or short
1. Check the thermistor.
2. Check the pump connection and
고착
E218
Heating return : thermistor open or short Check the thermistor.