Noritz NR50-OD User manual

1
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
sRefer to this manual whenever performing service or maintenance
on this appliance.
sThis manual will be used for service technician training seminars.
sThe specifications and descriptions in this manual may be changed
without prior notice.
sFor 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. Specications/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 Maintenance 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

2
Important Safety Information
To prevent damage to property and injury to the user, the icons below warn of
varying levels of risk.
Caution
Warning Ignoring this indication will cause an immediate danger of death or
serious injury.
Ignoring this indication may result in death or serious injury.
Prohibited.
1. Safety Tips for Service
tWear the appropriate clothing and protective gear:
In order to prevent injury or accident, wear a protective helmet, safety boots and a lifting
belt whenever necessary.
Caution
tUse only the appropriate tools and parts:
Warning Only use replacement parts manufactured by Noritz for this model as listed in the
Installation Manual Parts List for service on this unit. Use appropriate tools.
tModification of the unit is prohibited:
Do not attempt to modify or alter the unit.This will cause a fire hazard and a risk of
electrical shock.
tWhen servicing:
Warning Disconnect the power supply during maintenance and repairs to reduce the risk of
electric shock. If it is necessary to have the electricity connected during repairs, use
extreme caution not to touch parts that may cause a shock.
tDo not short circuit any safety device on this appliance:
If a safety device is not functioning properly, replace the part. Do not under any
circumstances short circuit the part.
tExhaust and gas leakage caution:
Warning Always check for leaks when installing or modifying the exhaust vent or gas piping.
2. Post-Service Checks
tCheck parts for leaks:
Caution Confirm that there are no gas, water, or exhaust leaks regardless of whether the
service performed could have caused them.
If the unit is installed indoors, check that the flue collar and vent pipe are installed
correctly and that they are in good condition. Confirm that there are no gas, water or
exhaust leaks regardless of whether the service performed could have caused them.
tCheck for combustibles:
Caution After service or maintenance is completed, check that there are no combustibles in
the vicinity of the unit.
tCheck insulation resistance:
Warning After service or maintenance is completed, measure the resistance between the elec-
trical wires and ground. If it is less than 10M:, there is a risk of electrical shock.
tProperly reconnect the power supply:
Warning Confirm that the power supply has been reconnected properly after service or main-
tenance is completed. Also confirm that there is no dust or other obstacles that might
cause an electric shock or a fire hazard.

3
1. Features
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4
Cold Water Cold Water Gas Gas Hot Water Hot Water
Condensate
Combustion Gas
Exhaust
About 120°F
Conventional
Type
Condensing
Tankless Gas
Water Heater
Water is heated
using the exhaust
gas which is about
400°F.
Primary Heat Exchanger
Primary Heat Exchanger
Secondary Heat Exchanger
Neutralizer
Combustion Gas
The condensing tankless gas water heater
discharges condensate.
When heat from the exhaust gas is collected within the
secondary heat exchanger, condensation occurs from
moisture in the exhaust gas and the resulting water is
discharged from the drain pipe (approx. 2 gallons/hour
(GPH) maximum). It is not a water leak. Do not plug or
block the drain line as it must always be allowed to freely
ow.
Drain pipe
(Installation example)
The condensing tankless gas water heater
tends to show white steam.
After the exhaust gas passes through the secondary heat
exchanger, it becomes low in temperature and moisture
rich which tends to produce steam at the vent discharge
terminal. This is a normal occurrence.
Condensate
comes out
from here.
During combustion, white
steam may often be seen.
This is normal.
Overview of Condensing Tankless Gas Water Heater
This water heater is a high efficiency, fully condensing appliance. Unlike a traditional tankless water heater, a
condensing type captures heat from the exhaust gas and uses it to preheat the incoming cold water as it passes
through the secondary heat exchanger as illustrated below.
Exhaust
About 400°F
About 400°F
About 400°F

5
2. Specications/Performance Table
NR50-OD / NR66 (-SV,-OD) / N-0531S (-OD) / NR71 (-SV,-OD) / N-0631S (-OD)
Installation Indoor/Outdoor,
Wall Mounted
Outdoor,
Wall Mounted
Air Supply/Exhaust
24.2"(Height) x 18.3"(Width) x
9.4"(Depth)
23.6"(Height) x 13.8"(Width) x
10.2"(Depth)
54 lbs. 55 lbs.
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
NG : 62W NG : 64W NG : 85W NG : 108W
LP : 75W LP : 77W LP : 100W LP : 96W
Casing
Flue Collar
Heat Exchanger
Anchoring Screws
Item
Model Name
Type
Ignition
Operating Pressure
Water Holding Capacity
Safety Devices
Accessories
Connection Sizes
Power Supply
Consumption
Materials
0.5 GPM
NR98-OD
NC199-OD
N-0751M-OD
NR98-DVC
NC199-DVC
N-0751M-DVC
Dimensions
Weight
Minimum Flow Rate
N-0751M-DV
Indoor,
Wall Mounted
Power Vented
Specication
NR98-SV
N-0751M
Direct Ignition
15-150 psi
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection Device (ZNR), Overheat Prevention Device, Freeze
Prevention Device, Fan Rotation Detector
23.6"(Height) x 13.8"(Width) x
9.4"(Depth)
47 lbs.
Freeze Prevention 145W
3/4"
3/4"
3/4"
120 VAC (60Hz)
Zincied Steel Plate/Polyester Coating
Stainless Steel
0.2 Gallon
Freeze Prevention 161W
Remote Controller, Remote Controller Cord, Anchoring Screws
NR98 (-SV,-OD,-DVC) / NC199 (-OD,-DVC) / N-0751M (-OD,-DV,-DVC)
Installation Indoor/Outdoor,
Wall Mounted
Outdoor,
Wall Mounted
Indoor/Outdoor,
Wall Mounted
Outdoor,
Wall Mounted
Air Supply/Exhaust
Connection Sizes Water Inlet
Hot Water Outlet
Gas Inlet
Power Supply Supply
NG : 54W NG : 51W NG : 59W NG : 46W
LP : 59W LP : 52W LP : 66W LP : 50W
Materials Casing
Flue Collar
Heat Exchanger
0.5 GPM
23.6"(Height) x 13.8"(Width) x 6.7"(Depth)
41 lbs.
0.2 Gallon
3/4"
Power Vented
Direct Ignition
15-150 psi
NR71-SV
N-0631S
NR71-OD
N-0631S-OD
Type
Item
Ignition
Operating Pressure
NR66-SV
N-0531S
NR66-OD
N-0531S-OD
Specication
20.5"(Height) x 13.8"(Width) x 6.7"(Depth)
36 lbs.
3/4"
3/4"
120 VAC (60Hz)
Freeze Prevention 141W (Optional for NR50-OD)
Zincied Steel Plate/Polyester Coating
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection Device (ZNR), Overheat Prevention
Device, Freeze Prevention Device (optional for NR50-OD), Fan Rotation Detector
Anchoring Screws
Model Name
Safety Devices
Accessories
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Consumption
NR50-OD
Outdoor,
Wall Mounted
33 lbs.
1/2"
NG : 36W
LP : 39W

6
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
NCC199-SV
N-0841MC
NCC199-DV
N-0841MC-DV
NRC111-SV
N-0842MC
NRC111-DV
N-0842MC-DV
Installation Indoor/Outdoor,
Wall Mounted
Outdoor,
Wall Mounted
Indoor/Outdoor,
Wall Mounted
Indoor,
Wall Mounted
Air Supply/Exhaust
Connection Sizes Water Inlet
Hot Water Outlet
Gas Inlet
Power Supply Supply
Materials Casing
Flue Collar
Heat Exchanger
Freeze Prevention 213W
Zincied Steel Plate/Polyester Coating
Consumption
Stainless Steel
24.4"(Height) x 18.4"(Width) x 9.4"(Depth)
73 lbs.
0.5 Gallon
NG : 106W
Stainless Steel
Copper Sheeting, Copper Tubing
Safety Devices
Flame Rod, Thermal Fuse, Pressure Relief Valve, Lightning Protection Device
(ZNR), Overheat Prevention Device, Freeze Prevention Device, Fan Rotation Detector
Accessories Remote Controller, Remote Controller Cord, Anchoring Screws
3/4"
3/4"
3/4"
120 VAC (60Hz)
LP : 109W
Dimensions
Weight
Water Holding Capacity
Ignition Direct Ignition
Operating Pressure 15-150 psi
Minimum Flow Rate 0.5 GPM
Item Specication
Model Name
Type
Power Vented
NR111-SV
NC250-SV-ASME
N-0931M
NR111-OD
N-0931M-OD
NR111-DV
NC250-DV-ASME
N-0931M-DV
NC380-SV-ASME
Installation Indoor/Outdoor,
Wall Mounted
Outdoor,
Wall Mounted
Indoor,
Wall Mounted
Indoor/Outdoor,
Wall Mounted
Air Supply/Exhaust
0.7 GPM
29.7"(Height) x 19.1"(Width) x 11.8"(Depth)
105 lbs.
0.6 Gallon
Connection Sizes Water Inlet 1"
Hot Water Outlet 1"
Gas Inlet 1"
Power Supply Supply
NG : 115W NG : 90W NG : 115W NG : 137W
LP : 115W LP : 95W LP : 120W LP : 142W
Freeze Prevention 371W
Materials Casing
Zincied Steel Plate/
Polyester Coating
(Stainless Steel for
ASME)
Zincied Steel Plate/
Polyester Coating
Zincied Steel Plate/
Polyester Coating
(Stainless Steel for
ASME)
Stainless Steel
Flue Collar
Heat Exchanger
Remote Controller, Remote Controller Cord, Anchoring Screws
120 VAC (60Hz)
Stainless Steel
Copper Sheeting, Copper Tubing
Safety Devices
Accessories
Specication
Power Vented
Direct Ignition
15-150 psi
Flame Rod, Thermal Fuse, Pressure Relief Valve, Lightning Protection Device (ZNR),
Overheat Prevention Device, Freeze Prevention Device, Fan Rotation Detector
3/4"
Consumption
Freeze Prevention 250W
Weight 62 lbs.
Water Holding Capacity 0.3 Gallon
3/4"
3/4"
Operating Pressure
Minimum Flow Rate 0.5 GPM
Dimensions 24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
Item
Model Name
Type
Ignition

7
Performance
Maximum Performance
Minimum Performance
Maximum Hot Water Capacity 45°F Rise
0.5 - 7.1 Gal./min.
Default Temperature Options 120, 130, 135 (for NR50-OD only), 140°F (Original is 120°F)
Temperature Settings (Using the Remote Controller) 100 - 150°F (In 5°F intervals), 160°F (12 Options)
NR66-SV
N-0531S
NR66-OD
N-0531S-OD
NR71-SV
N-0631S
Gas Consumption NG : 140,000 btuh LP : 140,000 btuh NG : 180,000 btuh LP : 180,000 btuh
NG : 20,000 btuh LP : 20,000 btuh NG : 25,000 btuh LP : 25,000 btuh
5.3 Gal./min. 6.3 Gal./min.
Capacity Range
Item
0.5 - 6.6 Gal./min.
NR71-OD
N-0631S-OD
NR98 (-SV,-OD)
N-0751M (-OD,-DV)
NR98-DVC
N-0751M-DVC
NCC199 (-SV,-DV)
N-0841MC (-DV)
NRC111 (-SV,-DV)
N-0842MC (-DV)
Maximum Performance
Minimum Performance NG : 12,000 btuh
LP : 12,000 btuh
Maximum Hot Water Capacity 45°F Rise
Item
Gas Consumption NG : 199,900 btuh LP : 199,900 btuh
7.5 Gal./min.
Capacity Range 0.5 - 9.8 Gal./min.
100 - 150°F (In 5°F intervals),
160, 170, 180°F (In 10°F intervals) (14 Options)
Default Temperature Options
NG : 11,000 btuh
LP : 11,000 btuh
8.4 Gal./min.
0.5 - 11.1 Gal./min.
120, 130, 140, 180°F (Original is 120°F)
Temperature Settings (Using the Remote Controller)
NR111-SV
NC250-SV-ASME
N-0931M (-ASME)
NR111-OD
N-0931M-OD
NR111-DV
NC250-DV-ASME
N-0931M-DV (-ASME)
NC380-SV-ASME
Maximum Performance NG : 380,000 btuh LP : 380,000 btuh
Minimum Performance NG : 22,500 btuh LP : 22,500 btuh
Maximum Hot Water Capacity 45°F Rise 13.2 Gal./min.
0.7 - 13.2 Gal./min.
Temperature Settings (Using the Remote Controller)
Default Temperature Options
100 - 150°F (In 5°F intervals),
160, 170, 180°F (In 10°F intervals) (14 Options)
120, 130, 140, 180°F (Original is 120°F)
Item
Gas Consumption NG : 250,000 btuh LP : 250,000 btuh
NG : 11,000 btuh LP : 11,000 btuh
9.3 Gal./min.
Capacity Range 0.5 - 11.1 Gal./min.
NR50-OD
NG : 120,000 btuh LP : 120,000 btuh
NG : 20,000 btuh LP : 20,000 btuh
4.2 Gal./min.
0.5 - 5.0 Gal./min.
Hot Water Supply Capabillities
NR50-OD
80
01 2 345 678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
012345678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
01 2 345 6 78
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
[Winter] Inlet Water Temp. 46˚F
Set Temperature (˚F)
[Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
Set Temperature (˚F)
Set Temperature (˚F)
NR66 (-SV,-OD) / N-0531S (-OD)
80
012345 678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
01 2 345 6 78
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
01 2 345 6 78
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
[Winter] Inlet Water Temp. 46˚F
Set Temperature (˚F)
[Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
Set Temperature (˚F)
Set Temperature (˚F)

8
80
0 1 2 3 4 5 6 7 8 9 10 11 12
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
0 123456 789101112
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
0 12 34567891011
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
NR98 (-SV,-OD,-DVC) / NC199 (-OD,-DVC) / N-0751M (-OD,-DV,-DVC)
80
0 1 2 3 4 5 6 7 8 9 10 11 12
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
80
0 123456 789101112
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
80
0 12 34567891011
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
NR111 (-SV,-OD,-DV) / NC250 (-SV,-DV)-ASME / N-0931M (-OD,-DV)
80
0 1 2 3 4 5 6 7 8 9 10 11 12
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
80
0 123456 789101112
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
80
0 12 34567891011
90
100
110
120
130
140
150
160
170
180
Set Temperature (˚F)
Flow Rate (GPM)
NCC199 (-SV,-DV) / N-0841MC (-DV) / NRC111 (-SV,-DV) / N-0842MC (-DV)
[Winter] Inlet Water Temp. 46˚F [Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
[Winter] Inlet Water Temp. 46˚F [Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
[Winter] Inlet Water Temp. 46˚F [Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
Set Temperature (˚F)
Set Temperature (˚F)
Set Temperature (˚F)
Flow Rate (GPM) Flow Rate (GPM) Flow Rate (GPM)
[Winter] Inlet Water Temp. 46˚F [Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
0 1.3 2.6 4 5.3 6.6 8 9.3 10.6 12 13.2 14.5
176
158
140
122
104
176
158
140
122
104
0 1.3 2.6 4 5.3 6.6 8 9.3 10.6 12 13.2 14.5
176
158
140
122
104
0 1.3 2.6 4 5.3 6.6 8 9.3 10.6 12 13.2 14.5
NC380-SV-ASME / N-1321M-ASME
Set Temperature (˚F) Set Temperature (˚F) Set Temperature (˚F)
Flow Rate (GPM)
80
0 12345678910
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM) Flow Rate (GPM)
80
0 12 345678910
90
100
110
120
130
140
150
160
170
180
80
0 12 345678910
90
100
110
120
130
140
150
160
170
180
NR71 (-SV,-OD) / N-0631S (-OD)
Set Temperature (˚F)
[Winter] Inlet Water Temp. 46˚F [Spring/Fall] Inlet Water Temp. 64˚F [Summer] Inlet Water Temp. 82˚F
Set Temperature (˚F)
Set Temperature (˚F)

9
Pressure Loss Characteristics
NOTE: Flow rates shown will vary slightly depending on the incoming water temperature and the setting temperature on the remote
controller.
NR50-OD
0
5
10
15
20
25
30
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Pressure Loss (psi)
0
10
20
30
40
50
60
Ft of Head
Flow Rate (gpm)
NR66 (-SV,-OD) / N-0531S (-OD)
0
5
10
15
20
25
30
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Pressure Loss (psi)
0
10
20
30
40
50
60
Ft of Head
Flow Rate (gpm)
0
5
10
15
20
25
30
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Pressure Loss (psi)
0
10
20
30
40
50
60
Ft of Head
Flow Rate (gpm)
NR71 (-SV,-OD) / N-0631S (-OD)
0
5
10
15
20
25
30
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0
Flow Rate (GPM)
Pressure Loss (psi)
Ft of Head
0.0
10.0
20.0
30.0
40.0
50.0
60.0
Bypass Closed
Set temperature:
125˚F or higher
Bypass Open
Set temperature:
120˚F or less
NR98 (-SV,-OD,-DVC) / NC199 (-OD,-DVC) /
N-0751M (-OD,-DV,-DVC)
NCC199 (-SV,-DV) / N-0841MC (-DV) /
NRC111 (-SV,-DV) / N-0842MC (-DV)
Flow Rate (GPM)
Pressure Loss (psi)
Ft of Head
0
5
10
15
20
25
30
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
Bypass Close
Set temperature:
125 ˚ F or higher
(Storage Tank Setting w/
System Controller: 170 -180
˚ F)
Bypass Open
Set temperature:
120
˚ F or less
(Storage Tank Setting w/
System Controller: 160
˚ F or less)
System Controllers are compatible with Commercial models only (NC199, NCC199, NC250, and NC380 Series). The Storage Tank
setting is a feature that is only available with SC-201-6M(-EXT), SC-201-12M, and SC-201-24M System Controller models. See System
Controller Manual for more information regarding installation and compatibility.

10
Pressure Loss Characteristics (continued)
0
5
10
15
20
25
30
30
35
45
55
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
Flow Rate (GPM)
Pressure Loss (psi)
Ft of Head
0.0
10.0
20.0
30.0
40.0
50.0
60.0
80.0
70.0
90.0
100.0
110.0
NR111 (-SV,-OD,-DV) / NC250 (-SV,-DV)-ASME /
N-0931M (-OD,-DV)
Bypass Close
Set temperature:
125
˚F or higher
(Storage Tank Setting w/System
Controller : 170 -180
˚ F)
Bypass Open
Set temperature:
120
˚ F or less
(Storage Tank Setting w/System
Controller : 160
˚ F or less)
Ft of Head
Flow Rate (GPM)
Pressure Loss (psi)
0
10
20
30
40
50
60
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
0
5
10
15
20
25
30
NC380-SV-ASME / N-1321M-ASME
Bypass Close
Set temperature:
145 ˚F or higher
(Storage Tank Setting w/System
Controller : 170 -180
˚ F)
Bypass Open
Set temperature:
140
˚ F or less
(Storage Tank Setting w/System
Controller : 160 ˚ F or less)
AIR INLET
AIR INLET
GAS INLET
COLD WATER INLET
WATER DRAIN VALVE
HOT WATER OUTLET
(WATER FILTER)
WATER DRAIN VALVE
WIRING THROUGHWAYS
13.3"
13.1"
13.8"
20.5"
0.4"
19.2"
0.4" 6.7"
1.2"
0.4"
21.4"
4.7"
2.4"
3.3"
0.4"
4.7"
COLD WATER INLET (3/4")
HOT WATER OUTLET (3/4")
7.0"
4.3"
1.5"
3.8"
1.6 "
GAS INLET (1/2")
10.0"
3.9"
7.2"
2.2"
(VIEW FROM TOP)
WIRING THROUGHWAYS
1.8"
1.9"
2.0"
UPPER WALL MOUNT BRACKETS
BOTTOM OF
CASE BOTTOM OF CASE
FLUE TERMINAL
1.7" 1.0"
LOWER WALL MOUNT BRACKETS
3. Dimensions
NR50-OD

11
NR66-SV / N-0531S
NR66-OD / N-0531S-OD
FLUE COLLAR
AIR INLET
AIR INLET
GAS INLET
COLD WATER INLET
WATER DRAIN VALVE
HOT WATER OUTLET
(WATER FILTER)
WATER DRAIN VALVE
WIRING THROUGHWAYS
13.3"
3"
13.1"
13.8"
20.5"
0.4"
3.2"
19.2"
0.4" 6.7"
3.0"
1.2"
0.4"
21.4"
4.7"
2.4"
3.3"
0.4"
4.7"
COLD WATER INLET (3/4")
HOT WATER OUTLET (3/4")
7.0"
4.3"
1.5"
3.8"
1.6"
GAS INLET (3/4")
10.0"
3.9"
7.2"
2.2"
WIRING THROUGHWAYS
1.8"
1.9"
2.0"
(VIEW FROM TOP)
UPPER WALL MOUNT BRACKETS
LOWER WALL MOUNT BRACKETS
BOTTOM OF CASEBOTTOM OF CASE
AIR INLET
AIR INLET
GAS INLET
COLD WATER INLET
WATER DRAIN VALVE
HOT WATER OUTLET
(WATER FILTER)
WATER DRAIN VALVE
WIRING THROUGHWAYS
13.3"
13.1"
8.4"
13.8"
20.5"
0.4"
19.2"
0.4" 6.7"
1.2"
0.4"
21.4"
4.7"
2.4"
3.3"
0.4"
4.7"
COLD WATER INLET (3/4")
HOT WATER OUTLET (3/4")
7.0"
4.3"
1.5"
3.8"
1.6"
GAS INLET (3/4")
10.0"
3.9"
7.2"
2.2"
(VIEW FROM TOP)
WIRING THROUGHWAYS
1.8"
1.9"
2.0" 1.7" 1.0"
LOWER WALL MOUNT BRACKETS
UPPER WALL MOUNT BRACKETS
BOTTOM OF CASE BOTTOM OF CASE

12
NR71-SV / N-0631S
4- 0.5"
2-0.3" x 0.5"
OBLONG HOLE
4.7"
2.0"
3.3"
2.4"
3.3"
4.7"
0.4" 24.5" 0.4"
1.2"
3.2"22.3"
0.4"
0.4"
3"
6.7"
1.1"
AIR INLET
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
WIRING THROUGHWAYS
GAS INLET
COLD WATER INLET
23.6"
13.8"
13.1"
4"
FLUE COLLAR
AIR INLET
LED
13.3"
(VIEW FROM TOP)
10.5"
7.8"
6.2"
1.4"
4.3"
2.5" 1.8"
1.9"
4.2"
1.7"
HEGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
HOT WATER OUTLET
COLD WATER INLET
GAS INLET
NR71-SV/N-0631S
1.8"
1.9"
2.0"
4- 0.5"
2-0.3" x 0.6"
OBLONG HOLE
HOT WATER OUTLET (3/4")
COLD WATER INLET (3/4")
GAS INLET (3/4")
WIRING THROUGHWAYS
NR71-OD / N-0631S-OD
‚b‚n‚k‚c
‚g‚n‚s ‚f‚`‚r
4- 0.5"
2-0.3" x 0.5"
OBLONG HOLE
4.7"
2.0"
3.3"
2.4"
3.3"
4.7"
3-0.3" x 0.6"
OBLONG HOLE
0.4" 24.5" 0.4"
1.2"
22.3"
0.4"
0.4" 6.7"
0.4"
1.1"
AIR INLET
(VIEW FROM TOP)
13.3"
13.8"
13.1"
10.0" 1.6"
AIR INLET
LED
10.5"
4.3"
2.5"
1.8"
7.8"
6.2"
1.4"
1.9"
4.2"
1.7"
1.0"1.7"
23.6"
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
WIRING THROUGHWAYS
GAS INLET
COLD WATER INLET
HEGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
HOT WATER OUTLET
COLD WATER INLET
GAS INLET
NR71-OD/N-0631S-OD
1.8"
1.9"
2.0"
FLUE TERMINAL
4- 0.5"
COLD WATER INLET (3/4")
HOT WATER OUTLET (3/4")
WIRING THROUGHWAYS
GAS INLET (3/4")

13
NR98-SV / N-0751M
NR98-SV/N-0751M
1.8"
2.2"
2.2"
13.8"
23.6"
13.1"
AIR INLET
1.2"
3.7"
22.3"
2.8"
0.4"
9.4"
0.4"
1.1"
AIR INLET
13.2"
GAS INLET
3.3"
0.4" 24.5"
4.7"
0.4"
2.4"
4.7"
2.0"
3.3"
4- 0.5"
2-0.3 x 0.5"
OBLONG HOLE
10.3"
7.1"
4.8"
2.8"
4.5" 5.9"
7.8"
3.1"
1.4"
7.0"
GAS INLET (3/4")
4- 0.5"
2-0.3 x 0.6" OBLONG HOLE
HEIGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
HOT WATER OUTLET
COLD WATER INLET
GAS INLET
WIRING THROUGHWAY
WA TER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
COLD WATER INLET
(120VAC)
(120VAC)
WIRING THROUGHWAY
WIRING THROUGHWAY
COLD WATER INLET (3/4")
WIRING THROUGHWAY
HOT WATER OUTLET (3/4")
(VIEW FROM TOP)
4"
FLUE COLLAR
NR98-OD / NC199-OD / N-0751M- OD
4- 0.5"
2-0.3 x 0.5" OBLONG HOLE
4- 0.5"
2-0.3 x 0.6" OBLONG HOLE
NR98-OD/NC199-OD/
N-0751M-OD
1.8"
2.2"
"2.2
GAS INLET
13.8"
23.6"
1.7" 2.1"
8.6" 2.9"
13.1"
AIR INLET
22.3"
0.4" 9.4"0.4"
1.2"
0.4"
1.1"
AIR INLET
0.4"
2.4"
4.7"
3.3"
24.5"
4.7"
0.4"
3.3"
2.0"
13.2"
GAS INLET
2.8"
4.5"
7.1"
10.3"
4.8"
7.8"
5.9"
1.4"
3.1"
7.0"
GAS INLET (3/4")
HEIGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
HOT WATER OUTLET
COLD WATER INLET
FLUE COLLAR
WIRING THROUGHWAY
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
WIRING THROUGHWAY
(120VAC)
COLD WATER INLET
(VIEW FROM TOP)
COLD WATER INLET (3/4")
WIRING THROUGHWAY
(120VAC)
WIRING THROUGHWAY
HOT WATER OUTLET (3/4")

14
N-0751M-DV
HOT WATER OUTLET (3/4")
WIRING THROUGHWAY
WIRING THROUGHWAY
AC120V
COLD WATER INLET (3/4")
GAS INLET (3/4")
(VIEW FROM TOP)
7.3"
8.1"
7.3"
2.6"
1.2"
6.9"
10.3"
6.0"
5.9"
4.1"
1.8"
0.5
0.5"
1.4"
0.2" x 0.4" OBLONG HOLE
0.2" x 0.4" OBLONG HOLE
5.5"
4.1"
2.8"
1.4"
5.5"
4.1"
2.8"
0.8"
26.0"
0.8"
2.9"
22.3"
2.5"
4.1"
1.1"
10.2"
0.4" - 1.8"
0.4" - 1.8"
WIRING THROUGHWAY
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE COLD WATER INLET
GAS INLET
(AC120V)
WIRING THROUGHWAY
13.2"
FLUE COLLAR
AIR INLET
5.0"
3.1"
13.1"
23.6"
13.8"
2.2"GAS INLET
2.2"COLD WATER INLET
1.8"
HOT WATER OUTLET
NR98-DVC/NC199-DVC/
N-0751M-DVC
FROM BOTTOM OF CASE
HEIGHT OF EACH FITTINGS
NR98-DVC / NC199-DVC / N-0751M-DVC
(120VAC)
WIRING THROUGHWAY
WIRING THROUGHWAY
(VIEW FROM TOP)
HOT WATER OUTLET (3/4")
COLD WATER INLET (3/4")
GAS INLET (3/4")
12.5"
2.1"
5.9"
5.4"
10.8"
4.8"
4.5"
9.4"
3.7"
2.8"
26.2"
6.7"
5.5"
3.9"
2.8"
1.4"
6.7"
5.5"
3.9"
2.8"
1.4"
17.7"
(120VAC)
WIRING THROUGHWAY
WIRING THROUGHWAY
COLD WATER INLET
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
GAS INLET
1.1"
3"
0.4"
23.1"
9.4"
0.4"
3.7"
1.6"
FLUE COLLAR
AIR INLET
17.6"
9.1"
5.9"
24.2"
18.3"
2.2"GAS INLET
2.2"COLD WATER INLET
1.8"HOT WATER OUTLET
N-0751M-DV
HEIGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
4- 0.5"
6-0.24 x 0.4"OBLONG HOLE
4- 0.5"
6-0.24 x 0.4" OBLONG HOLE
4"4"

15
NCC199-DV / N-0841MC-DV / NRC111-DV / N-0842MC-DV
5.9" 9.2"
18.4"
17.6"
24.4"
LED
17.7"
23.1"
3.1"
0.4" 9.4"
5.1"
1.1"
0.4"
2.8"
2.4"
4.3"
3.9"
8.4"
5.3"
2.8"
10.0"
6.1"
3.9"
6.1"
10.4"
13.7"
4.7"
(120VAC)
26.2"
1.4"
2.8"
3.9"
5.5"
1.4"
2.8"
3.9"
5.5"
6.7"
1.6"
4- 0.5"
6- 0.24 x 0.4" OBLONG HOLE
6.7"
HEIGHT OF EACH FITTING
FROM BOTTOM OF CASE
NCC199-DV/N-0841MC-DV/
NRC111-DV/N-0842MC-DV
0.9"
HOT WATER OUTLET
COLD WATER INLET
GAS INLET
4"4"
AIR INLET FLUE COLLAR
WIRING THROUGHWAY
WATER DRAIN VALVE
HOT WATER OUTLET
WATER DRAIN VALVE
COLD WATER INLET
WATER DRAIN VALVE
(WATER FILTER)
WIRING THROUGHWAY
GAS INLET
WATER DRAIN VALVE
WIRING THROUGHWAY
(120VAC)
WIRING THROUGHWAY
HOT WATER OUTLET (3/4")
WIRING THROUGHWAY
GAS INLET (3/4")
WIRING THROUGHWAY
COLD WATER INLET(3/4")
(VIEW FROM TOP)
4- 0.5"
6- 0.24 x 0.4" OBLONG HOLE
CONDENSATE DRAIN CONDENSATE DRAIN
CONDENSATE DRAIN (1/2")
1.7"
2.2"
NCC199-SV / N-0841MC / NRC111-SV / N-0842MC
4- 0.5"
6-0.24 x 0.4" OBLONG HOLE
6.7"
5.5"
3.9"
2.8"
1.4"
0.4"
9.4"
5.1"
1.6"
26.2" 23.1"
24.4"
3.1"
FLUE COLLAR
1.1"
0.4"
1.4"
2.8"
3.9"
5.5"
6.7"
6-0.24 x 0.4" OBLONG HOLE
AIR INLET
17.7"
COLD WATER INLET
WATER DRAIN VALVE
HOT WATER OUTLET
WATER DRAIN VALVE
CONDENSATE DRAIN
WIRING THROUGHWAY
(120VAC)
WIRING THROUGHWAY
WATER DRAIN VALVE
GAS INLET
WIRING THROUGHWAY
(WATER FILTER)
WATER DRAIN VALVE
HOT WATER OUTLET (3/4")
WIRING THROUGHWAY
2.8"
3.9"
COLD WATER INLET (3/4")
WIRING THROUGHWAY
GAS INLET (3/4")
WIRING THROUGHWAY
6.1" 4.3"
6.1"
5.3" 4.7"
2.8"
2.4"
13.7"
10.4"
10.0"
8.4"
3.9"
(AC120VAC)
AIR INLET
LED
(VIEW FROM TOP)
HEIGHT OF EACH FITTING
FROM BOTTOM OF CASE
CONDENSATE DRAIN
HOT WATER OUTLET
COLD WATER INLET
GAS INLET 2.2"
2.2"
1.7"
0.9"
NCC199-SV/N-0841MC
NRC111-SV/N-0842MC
18.4"
17.6"
4"
4- 0.5"
CONDENSATE DRAIN (1/2")
2.2"
9.1"5.9"
448 [17.6"]
464 [18.3"]
5.1" 5.1"
17.6"
18.3"
5.1"
NRC111-SV/
N-0842MC
NRC111-DV/
N-0842MC-DV

16
NR111-OD / N-0931M-OD
NR111-OD/N-0931M-OD
1.7"
2.2"
"2.2GAS INLET
10.6" 3.2"
1.7" 2"
18.3"
24.2"
17.6"
AIR INLET
LED
17.7"
GAS INLET
1.6"
9.4"0.4"
0.4"
0.4"
AIR INLET
26.2"
23.1"
1.4"
2.8"
3.9"
5.5"
6.7"
1.4"
2.8"
3.9"
5.5"
6.7"
7.7"
2.6"
2.8"
3.9"
6.1"
11"
5.3"
5.4"
14.4"
6.3"
6.9"
2.9"
GAS INLET (3/4")
(120VAC)
4- 0.5"
6 - 0.24 x 0.4" OBLONG HOLE
4- 0.5"
6 - 0.24 x 0.4" OBLONG HOLE
HEIGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
WATER OUTLET
WATER INLET
FLUE COLLAR
WIRING THROUGHWAYS
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
WIRING THROUGHWAY
(120VAC)
COLD WATER INLET
HOT WATER OUTLET (3/4")
WIRING THROUGHWAYS
COLD WATER INLET (3/4")
(VIEW FROM TOP)
WIRING THROUGHWAY
NR111-SV / NC250-SV-ASME / N-0931M
NR111-SV/NC250-SV-ASME/
N-0931M
1.7"
2.2"
"2.2GAS INLET
18.3"
24.2"
17.6"
AIR INLET
LED
17.7"
1.6"
0.4"
23.1"
0.4" 9.4"
3.7"
2.7"
1.1"
AIR INLET
5.5"
5.5"
3.9"
3.9"
1.4"
2.8"
6.7"
1.4"
2.8"
6.7"
26.2"
GAS INLET
2.6"
2.8"
6.9"
5.3"
5.4"
6.3"
11"
14.4"
7.7"
6.1"
3.9"
2.9"
GAS INLET (3/4")
4- 0.5"
6-0.24 x 0.4" OBLONG HOLE
4- 0.5"
6-0.24 x 0.4" OBLONG HOLE
FLUE COLLAR
WIRING THROUGHWAYS
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE WIRING THROUGHWAY
(120VAC)
COLD WATER INLET
HEIGHT OF EACH FITTINGS
FROM BOTTOM OF CASE
HOT WATER OUTLET
COLD WATER INLET
(VIEW FROM TOP)
WIRING THROUGHWAY
(120VAC)
COLD WATER INLET (3/4")
WIRING THROUGHWAYS
HOT WATER OUTLET (3/4")
4"

17
NR111-DV / NC250-DV-ASME / N-0931M-DV
(120VAC)
WIRING THOROUGHWAY
WIRING THOROUGHWAYS
(VIEW FROM TOP)
HOT WATER OUTLET (3/4")
COLD WATER INLET (3/4")
GAS INLET (3/4")
2.9"
6.1"
3.9"
7.7"
14.4"
11"
5.4"
6.9"
6.3"
5.3"
2.8"
2.6"
6.7"
5.5"
3.9"
2.8"
1.4"
6.7"
5.5"
3.9"
2.8"
1.4"
26.2"
1.1"
3"
9.4"
3.7"
23.1"
0.4"
0.4"
1.6"
(120VAC)
WIRING THROUGHWAY
WIRING THROUGHWAYS COLD WATER INLET
WATER DRAIN VALVE
(WATER FILTER)
HOT WATER OUTLET
WATER DRAIN VALVE
GAS INLET
17.7"
AIR INLET
FLUE COLLAR
LED
17.6"
5.9" 9.1"
24.2"
18.3"
2.2"GAS INLET
2.2"COLD WATER INLET
1.7"HOT WATER OUTLET
NR111-DV/NC250-DV-ASME/
N-0931M-DV (-ASME)
FROM BOTTOM OF CASE
HEIGHT OF EACH FITTINGS
4- 0.5"
6-0.24 x 0.4" OBLONG HOLE
4" 4"
4- 0.5"
6- 0.24 x 0.4" OBLONG HOLE
NC380-SV-ASME / N-1321M-ASME
2.2"GAS INLET
3.4"COLD WATER INLET
2.6"HOT WATER OUTLET
NC380-SV-ASME /
N-1321M-ASME
FROM BOTTOM OF CASE
HEIGHT OF EACH FITTINGS
FLUE COLLAR AND ADAPTER
LED
AIR INLET
COLD WATER INLET
(WATER FILTER)
GAS INLET
WATER DRAIN VALVES
WIRING THROUGHWAYS
WATER DRAIN VALVE
HOT WATER OUTLET
LOWER WALL MOUNT BRACKETS
UPPER WALL MOUNT BRACKETS
WIRING THROUGHWAYS
HOT WATER OUTLET (1”)
(VIEW FROM TOP)
GAS INLET (3/4”)
COLD WATER INLET (1”)

18
RC-7649M (Optional for NR50-OD / NR66 (-SV,-OD) / N-0531S (-OD) /
NR71 (-OD) / N-0631S (-OD))
5.0"
4.7"
0.8"
RC-7650M (Optional Canadian Version)
5.0"
4.7"
0.8"

19
NR50-OD / NR66-OD / N-0531S-OD
4. Components
G.F.C.I
ENW
Exhaust Terminal
Anti-Frost Heater*
Anti-Frost Heater*
High-Limit Switch
Flame Rod
Ignition Electrode
Manifold
Heat Exchanger
Thermal Fuse
Gas Valve Unit
Gas Inlet
Cold Water Inlet
Hot Water Outlet
Water Drain Valve
Water Flow Sensor
Circuit Board
Igniter
Fan Motor
Flow Control Valve
* Freeze protection kit is an optional accessory for the NR50-OD model and is not included with the unit.
For cold weather installations, the optional Freeze Protection Kit (#SKG7772) is required in order to
prevent internal freezing. For more information about the Freeze Protection Kit, please contact Noritz
Technical Support at 1-866-766-7489.

20
NR66-SV / N-0531S
‚P‚U‚`
‚P‚U‚`
G.F.C.I
Hot Water Outlet
Anti-Frost Heater
Flow Control Valve
Heat Exchanger
Frost Sensing Switch
Anti-Frost Heater
High-Limit Switch
Flame Rod
Exhaust Flue
Ignition Electrode
Manifold
Gas Valve Unit
Circuit Board
Thermal Fuse
Igniter
Water Filter
Cold Water Inlet
Gas Inlet
ENW