Navien NCB-150E, Service Manual, Page: 84 / 157

Troubleshooting 83
5.2 Error Code List
Error Code Sub Code Function Self-diagnostic/Action
E001 0 Overheating of heat exchanger
●
Clean the Strainer
●
Check the Pump for proper voltage from PCB(120AC)
●
Check for proper flow rate and circulation through the
heating line.
●
Check the heat exchanger; a flush with a cleaning solution.
E003 0 Ignition failure
●
Tighten the ground connection screws on heat exchanger.
●
Check to see if the main gas supply valve is open.
●
Verify that gas pressure is within operating range.
●
Check gas system and orifice.
●
Check Dual Venturi for proper operation.
●
Check for proper dipswitch settings (see page 20)
E004 0 FALSE flame detection
●
Ensure ground wire is connected.
●
Check the igniter for spark.
E012 0 Flame loss
●
Tighten the ground connection screws on heat exchanger.
●
Check the main gas line (Is the valve open?).
●
Verify gas pressure is within operating range.
●
Check gas meter for proper BTU capacity.
●
Check flame rod and verify [K] value in DIAGNOSTIC mode.
●
Check intake air filter.
●
Check ground wire.
●
Check power supply.
●
Tighten the ground connection screws on heat exchanger.
E016 0 Overheating of heat exchanger
●
Clean the inlet water filter and Strainer.
●
Check High Limit Switch.
●
Check for proper dipswitch settings (see page 20)
●
Check the 3 way valve.
●
Check the heat exchanger; a flush may be necessary.
●
Turn OFF the system for at least 30 minutes then restart.
E030 0
Exhaust Overheat: exhaust limit sensor shuts
down the unit when the flue temperature
exceeds 230 °F (110 °C) for more than 10
seconds.
●
Turn OFF the system for at least 30 minutes then restart.
●
Clean the inlet water filter and Strainer.
●
Check exhaust thermistor and verify [P] value in
DIAGNOSTIC mode.
●
Check the heat exchanger; a flush may be necessary.
E046 2 Abnormal heat exchanger High Limit Switch
●
Check heat exchanger High Limit Switch connection
●
Check for proper connection to the PCB.
E047
1 Abnormal exhaust thermistor (open)
●
Check exhaust thermistor connection.
2 Abnormal exhaust thermistor (short)
●
Check for proper connection to the PCB.
E060
1
Abnormal Dual Venturi Limit Switch operation
(ON)
●
Check the Dual Venturi connection.
2
Abnormal Dual Venturi Limit Switch operation
(Close OFF)
●
Test Dual Venturi for proper operation using TEST mode.
3
Abnormal Dual Venturi Limit Switch operation
(Open ON)
●
Check gas orifice for obstructions.