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NORITZ America Corporation
Gas Water Heater
NR50-OD
NR66 (-SV,-OD) / N-0531S (-OD)
NR71 (-SV,-OD) / N-0631S (-OD)
NR98 (-SV,-OD,-DVC) / NC199 (-OD, -DVC) / N-0751M (-OD,-DVC)
NCC199 (-SV,-DV) / N-0841MC (-DV)
NRC111 (-SV,-DV) / N-0842MC (-DV)
NR111 (-SV,-OD,-DV) / NC250 (-SV,-DV)-ASME / N-0931M (-OD,-DV)
NC380-SV-ASME / N-1321M-ASME
Service Manual
s Refer to this manual whenever performing service or maintenance
on this appliance.
s This manual will be used for service technician training seminars.
s The specifications and descriptions in this manual may be changed
without prior notice.
s For further assistance, contact Noritz Technical Support at 1-866-
766-7489.
Do not short circuit any safety device on
this appliance
Rev: July, 2011
Contents
WS-06-9019E
Important Safety Information 2
1. Features 3
2. Specications/Performance Tables 5
3. Dimensions 10
4. Components 19
5. Operating Principle 34
6. Operation Flow Chart 44
7. Wiring Diagram 49
8. Troubleshooting 54
Error Codes and Checkpoints 54
Circuit Board Checkpoints 57
Error Descriptions and How to Reset 62
Remote Controller (Optional for NR50-OD/NR66/N-0531S Series, NR71/N-0631S Series) 71
Displaying Maintenan
ce Monitor 72
Maintenance Monitor List 73
Circuit Board Replacement 75
Changing the Fan Motor 79
Neutralizer Life Cycle Warning and Replacement Procedures (condensing models only)
80
Gas Line Requirements 82
Manifold Gas Pressure Adjustment 83
Periodic Inspection 88
Periodic Maintenance 89
Changing Default Temperature Setting 90
9. Installation Check 94