Noritz NR501 Series Service Manual

1
NORITZ America Corporation
Gas Water Heater
NR501-OD
NR662-OD
NRC661 (-DV, -OD)
NRC711 (-DV,-OD)
Service Manual
• Refer to this manual whenever performing service or
maintenance on this appliance.
• This manual will be used for service technician training seminars.
• The specifications and descriptions in this manual may be
changed without prior notice.
• For further assistance, contact Noritz Technical Support at
1-866-766-7489.
Do not short circuit any safety device on
this appliance
Rev: Dec, 2013
Contents
Important Safety Information .................................................................................................... 2
1. Specifications/Performance Table ....................................................................................... 3
2. Dimensions ......................................................................................................................... 9
3. Components ....................................................................................................................... 12
4. Operating Principle ............................................................................................................. 16
5. Operation Flow Chart .......................................................................................................... 19
6. Wiring Diagram ................................................................................................................... 25
7. Troubleshooting .................................................................................................................. 28
• Error Codes and Checkpoints ......................................................................................... 28
• Circuit board checkpoints ................................................................................................ 29
• Error Code Diagnostic Flow Charts .............................................................................. 31
• Displaying Maintenance Monitors ................................................................................... 59
• Maintenance Monitor List ................................................................................................ 60
• Circuit Board Replacement ............................................................................................. 61
• When Changing the Fan Motor ....................................................................................... 63
• Gas Line Requirements ................................................................................................... 64
• Manifold Gas Pressure Adjustment ................................................................................. 67
• Water Treatment ............................................................................................................. 73
• Periodic lnspection ......................................................................................................... 68
• Periodic Maintenance ..................................................................................................... 69
• Changing Default Temperature Setting ........................................................................... 75
8. Installation Check .............................................................................................................. 79
KS-11-0004
• Preventing Freeze Damage .................................................................................................. 76

Noritz NR501 Series Specifications

General

Fuel Type	Natural Gas or Propane
Heating Capacity	Up to 199, 900 BTU/h
Maximum BTU Input	199, 900 BTU/h
Minimum BTU Input	15, 000 BTU/h
Voltage	120 VAC
Frequency	60 Hz
Heat Exchanger Material	Copper
Temperature Range	100°F - 140°F
Type	Tankless Water Heater
Weight	Varies by model
Vent Type	Direct Vent
Category	Residential
Gas Type	Natural Gas or Propane
Input BTU/h	199, 900 BTU/h
Efficiency	82%
Warranty	12 years heat exchanger, 5 years parts
Inlet/Outlet Connection Size	3/4 inch
Gas Connection Size	3/4 inch