Noritz NR50-OD Service Manual

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Noritz NR50-OD Service Manual Manual pdf 54 page image

54DescriptionIgnition Failure(Initial Flame Faultdetection)Flame Rod Does NotDetect Flame (SecondaryFlame Fault Detection)Thermal FuseTriggeredAbnormally High OutputTemperatureHigh Limit SwitchTriggered.Inlet ThermistorAbnormalityOutlet ThermistorAbnormalityFan Motor AbnormalityHeat Exchanger FlowAbnormalityCheck for scale build-up in heat exchanger. Check forabnormal combustion. Check flue blockage or obstruction.Check that flame ignites all across the burner.Circuit board AbnormalityGas Solenoid Valve DriveCircuit AbnormalityRemote ControllerTr ansmission AbnormalityCircuit board setting abnormality(High elevation connector,dipswitch, etc)Combustion Abnormality(Warning Indication)Combustion Abnormality(Unit Shuts Off)Flame Rod circuitAbnormality(Detection of Flame whenno flame is present)Combustion Abnormality(BTU Drop)(Unit Continues Working)Display10111214162031326159707172739099760To reset this error code, the power needs tobe diconnected and then reconnected.To reset this error code, the power needs tobe disconnected and then reconnected.To reset this error code, the power needs to bedisconnected and then reconnected.To reset this error code, the power needs to bedisconnected and then reconnected.To reset this error code, the power needs tobe disconnected and then reconnected.Check for abnormal combustion.Check flue for blockage or obstruction.Check for melting or damage to the thermal fuse ( ).Check for improper connection of thermal fuse.Check if high limit switch is triggered ( ). Check forimproper connection of high limit switch.Measure the resistance through the inlet thermistor ( ).Check for an open or short circuit. Check for improperconnection to the inlet thermistor.Check that the fan is rotating. Check the pulse frequency fromthe fan rotational frequency sensor ( ). Check for improperconnection of the fan. Check voltage from circuit board.Check for damage to the gas solenoid vavle drive circuit onthe circuit board.Measure the current from the flame rod when there is noflame ( ). Check for a ground fault.Check connection from remote controller to circuit board.Check remote controller and circuit board for damage.Check for abnormal combustion.Check flue for blockage or obstruction.Measure the resistance through the outlet thermistor ( ).Check for improper connection or an open or short circuit.Check gas supply piping and pressure. Check for igniterspark ( ). Check gas solenoid valves ( ). Check flamerod ( ). Check ground, paying special attention to the groundconnection to the circuit board.1211113346 75Note 1)Note 1)Note 1)Note 1) This error code is not mentioned in the flowchart.Check for abnormal combustion.Check flue for blockage or obstruction.Check that flame ignites all across the burner.Combustion abnormality(Unit Shuts Off)Check for abnormal combustion.Check flue for blockage or obstruction.Check for proper setting of maintenance writers on circuit board.Check the circuit board (microcomputer) for damage. Check theDip switch. Check the "Control switch connector"(ex. high elevation connector etc.).8. TroubleshootingError Codes and Checkpoints (With optional remote controller connected)

Error Codes and Checkpoints for NR71/N-0631S Series Only (No remote controller connected)No. ofFlashesReset Method(without RemoteController)Will UnitWork AfterBeing ResetOther SymptomsNo ResetYESIt's available to burn even before reset.It's available to burn even before reset.109011 127273905916If minimum flow rate is available immediately61If power button is on immediately3220727199NO 70Error CodeRepresentationNONONO543Contin-uousFlashing Disconnect PowerDisconnect PowerTurn Off WaterReset Method(with RemoteController)Turn Off WaterDisconnect PowerTurn Off Water Turn Off WaterTurn Off WaterDisconnect PowerDisconnect PowerDisconnect PowerDisconnect PowerPower ButtonPower ButtonTurn Off WaterPower ButtonPower ButtonTurn Off WaterYESYESYESYESYESYESYESTurning off the water will only reset the unit if thereis no remote controller installed.If minimum flow rate is available immediatelyWhen adjusting the manifold gas pressure, be sure to remove the exhaust flue, the air inlet and the flue collar.Diagnosis Point (Trouble Point) Remarks8 9 10 1112Check for accidental extinction of the flame. Check forabnormal combustion, check gas solenoid valves, checkflame rod ( ). Check ground, especially on circuit board.Measure the resistance through the outlet thermistor ( ).Check for proportional gas valve trouble ( )4Circuit board failureYESNo Reset 903114Turn Off Water