30
Error Code Possible Cause
Check Point (Location of Failure)
113
Ignition failure
Is the gas valve closed?
Does the igniter spark?
Are all wiring connections to the gas valves secure?
Is the lead from the flame rod securely connected?
123
Flame rod is triggered
Is the gas valve closed?
Are all wiring connections to the gas valves secure?
Is the lead from the flame rod securely connected?
163
Hot water temperature does not
The heating load might be too large.
stabilize
Is the hot water temperature higher than 131
°
F (55
°
C) or more?
If the hot water temperature is lower than 131
°
F (55
°
C), adjust
the flow in the heating circuit and/or check the temperature
setting on the operation panel.
633
PRIORITY 1 pump abnormality,
Is the pump running?
water flow switch failure
Is the fuse inside the boiler blown?
Is the wiring for the flow switch properly connected?
643
PRIORITY 2 pump abnormality,
Is the pump running?
water flow switch failure
Is the fuse inside the boiler blown?
Is the wiring for the flow switch properly connected?
733
Circuit board setting abnormality,
This error code is displayed when the high elevation connector is
high elevation connector
disconnected or connected while the boiler has power.
Disconnect power to the boiler before making this adjustment.
903
Abnormal combustion
Check if there is any obstruction of the intake/exhaust pipe.
Error descriptions and possible cause / check points
The error codes in bold cannot be reset by turning the boiler OFF on the operation panel.
Disconnect, then reconnect electrical power to the boiler to reset the system.
Please contact Noritz America if any other error code appears.
