Troubleshooting; Error Codes And Checkpoints - Noritz NR50-OD Service Manual

8. Troubleshooting

When adjusting the manifold gas pressure, be sure to remove the exhaust flue, the air inlet and the flue collar.
<NR50-OD / NR66 (-SV,-OD) / N-0531S (-OD), NR71 (-SV,-OD) / N-0631S (-OD)>
Error Codes and Checkpoints (With optional remote controller connected)
Display
Description
Combustion Abnormality
Check for abnormal combustion.
10 (BTU Drop)
Check flue for blockage or obstruction.
(Unit Continues Working)
Check gas supply piping and pressure. Check for igniter
Ignition Failure
spark (
11 (Initial Flame Fault
rod (
detection)
connection to the circuit board.
Check for accidental extinction of the flame. Check for
Flame Rod Does Not
abnormal combustion, check gas solenoid valves, check
12 Detect Flame (Secondary
Flame Fault Detection) flame rod (
Check for melting or damage to the thermal fuse (
Thermal Fuse
14
Triggered Check for improper connection of thermal fuse.
Measure the resistance through the outlet thermistor (
Abnormally High Output
16
Check for proportional gas valve trouble (
Temperature
Check if high limit switch is triggered (
20 High Limit SwitchTriggered.
improper connection of high limit switch.
Measure the resistance through the inlet thermistor (
Inlet Thermistor
31 Check for an open or short circuit. Check for improper
Abnormality
connection to the inlet thermistor.
Outlet Thermistor
Measure the resistance through the outlet thermistor (
32
Abnormality Check for improper connection or an open or short circuit.
Check for scale build-up in heat exchanger. Check for
Heat Exchanger Flow
59
abnormal combustion. Check flue blockage or obstruction.
Abnormality
Check that flame ignites all across the burner.
Check that the fan is rotating. Check the pulse frequency from
61
Fan Motor Abnormality the fan rotational frequency sensor (
connection of the fan. Check voltage from circuit board.
70
Circuit board Abnormality Circuit board failure
Gas Solenoid Valve Drive Check for damage to the gas solenoid vavle drive circuit on
71
Circuit Abnormality
the circuit board.
Flame Rod circuit
Measure the current from the flame rod when there is no
Abnormality
72
flame (
(Detection of Flame when
no flame is present)
Check for proper setting of maintenance writers on circuit board.
Circuit board setting abnormality
Check the circuit board (microcomputer) for damage. Check the
73
(High elevation connector,
Dip switch. Check the "Control switch connector"
dipswitch, etc)
(ex. high elevation connector etc.).
Remote Controller Check connection from remote controller to circuit board.
760
Tr ansmission Abnormality
Check remote controller and circuit board for damage.
Combustion Abnormality
Check for abnormal combustion.
(Warning Indication)
Check flue for blockage or obstruction.
90
Check for abnormal combustion.
Combustion abnormality
Check flue for blockage or obstruction.
(Unit Shuts Off)
Check that flame ignites all across the burner.
Combustion Abnormality
Check for abnormal combustion.
99
(Unit Shuts Off)
Check flue for blockage or obstruction.
Note 1) This error code is not mentioned in the flowchart.
Error Codes and Checkpoints for NR71/N-0631S Series Only (No remote controller connected)
Reset Method Reset Method
No. of
(without Remote (with Remote
Flashes
Controller) Controller)
No Reset No Reset
Contin-
Turn Off Water Turn Off Water
uous
Flashing
Disconnect Power Power Button
Disconnect Power Power Button
3
Turn Off Water
Turn Off Water
Turn Off Water Turn Off Water
4 Disconnect Power
Power Button
Turn Off Water
Turn Off Water
Disconnect Power Disconnect Power
Power Button
5 Disconnect Power
Disconnect Power
Diagnosis Point (Trouble Point)
). Check gas solenoid valves (
8 9 10 11
). Check ground, paying special attention to the ground
12
12 ). Check ground, especially on circuit board.
)
11
). Check for
13
). Check for improper
6 7
5 ). Check for a ground fault.
Will Unit
Work After
Being Reset
YES It's available to burn even before reset.
YES
YES
YES
It's available to burn even before reset.
YES
If minimum flow rate is available immediately
NO
Turning off the water will only reset the unit if there
YES
is no remote controller installed.
If power button is on immediately
NO
If minimum flow rate is available immediately
YES
YES
NO
YES
NO
Remarks
To reset this error code, the power needs to
be diconnected and then reconnected.
). Check flame
).
1
).
4
To reset this error code, the power needs to
be disconnected and then reconnected.
).
3
).
4
Note 1)
To reset this error code, the power needs to be
disconnected and then reconnected.
Note 1)
Note 1)
To reset this error code, the power needs to
be disconnected and then reconnected.
To reset this error code, the power needs to be
disconnected and then reconnected.
Other Symptoms
54
Error Code
Representation
10
90
90
11 12
90
59
16
31
61
14
32
20
72
72
71
99
70 73