Noritz N-0531S User manual

1
NORITZ America Corporation
Gas Water Heater
Field Manual
The materials in this manual are presented for reference
only. For further assistance, contact Noritz Technical
Support at 866-766-7489.
be changed without prior notice.
Do not short circuit any safety
device on this appliance
Rev: Jan, 2009
Contents
Important Safety Information .........................................................................................................................................
1. Features ...........................................................................................................................................................................
.....................................................................................................................................
3. Dimensions ....................................................................................................................................................................
4. Components .................................................................................................................................................................
5. Troubleshooting ..........................................................................................................................................................
Error Codes and Checkpoints ............................................................................................................................
Remote Controller .................................................................................................................................................
Displaying Maintenance Monitor ....................................................................................................................
Maintenance Monitor List ...................................................................................................................................
Gas Line Requirements ........................................................................................................................................
Periodic Inspection ................................................................................................................................................
Periodic Maintenance ..........................................................................................................................................
Changing Default Temperature Setting .........................................................................................................
6. Installation Check .......................................................................................................................................................
2.
2
3
5
20
29
44
44
46
46
47
50
52
52
55
58
N-0531S (-OD)
N-0631S (-OD)
N-0751M (-DV, -OD, -DVC)
N-0931M (-DV, -OD)
N-0841MC (-DV)
N-1321M-ASME
Neutralizer Life Cycle Warning/Replacement Procedures....................................................................... 48
Draining Water for Maintenance or Freeze Protection ............................................................................
57

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
W ear 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
Use 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.
When 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.
Do 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.
Exhaust and gas leakage caution:
Warning Always check for leaks when installing or modifying the exhaust vent or gas piping.
2. Post-Service Checks
Check parts for leaks:
Caution
If the unit is installed indoors, check that the ue collar and vent pipe are installed
correctly and that they are in good condition. Conrm that there are no gas, water, or
exhaust leaks regardless of whether the service performed could have caused them.
Check for combustibles:
Caution After service or maintenance is completed, check that there are no combustibles in
the vicinity of the unit.
Check 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.
Properly reconnect the power supply:
Warning
Do not attempt to modify or alter the unit. This will cause a re hazard and a risk of
electrical shock.
Conrm that there are no gas, water, or exhaust leaks regardless of whether the
service performed could have caused them.
Conrm that the power supply has been reconnected properly after service or main-
tenance is completed. Also conrm that there is no dust or other obstacles that might
cause an electric shock or a re hazard.
Modication of the unit is prohibited:

3
1. Features
1. Quick Connect Multi System (For N-0751M series, N-0931M series, N-0841MC series, and N-1321M-ASME only)
Allows the simple installation of up to 2 units linked together using a Quick Connect Cord
CCP Valve
System Controller
2. Secondary Recirculation Pump in a Multi-System (For N-0931M series, N-0841MC series, and N-1321M-ASME only)
T wo recirculation pumps can be connected to the multi-system controller to provide a rotational pump system.
The multi-system controller will rotate the run time of each pump to increase pump life and also provide a backup
should one pump fail.
3. Multi-System Rotation Timing (For N-0931M series, N-0841MC series, and N-1321M-ASME only)
(1) In a multi-system installation, the system controller rotates the primary unit every 8 hours of accumulated
combustion time.
of up to 16 hours).
(3) Rotation is made every 24 hours, regardless of the burn, to ensure even wear.
4. Maximum Remote Controller Length (Only one remote controller can be connected.)
Remote controller (1 unit): Cord can be extended up to 300' with 18AWG wire.
* Note: In a Quick Connect Multi-System, only one remote controller will be installed.
(For N-0751M series, N-0931M series, N-0841MC series, and N-1321M-ASME only)
5. Temperature Lockout Function
The remote controller can be set to restrict the maximum allowable temperature setting for added safety.
See page 55-56 for details.
6. Elevation Adjustment
of the unit. No additional equipment or adjustments are necessary. See the "Installation Manual" for details.
Not required

4
Cold water Cold water Gas Gas Hot water Hot water
Condensate
Combustion gas
About 400°F
About 400°F
tsuahxEtsuahxE
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
About 400°F
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
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 eciency, 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.

5
N-0531S
Indoor/ Outdoor, Wall Mounted
Direct Ignition
15-150 psi
0.5 GPM
20.5"(Height) x 13.8"(Width) x 6.7"(Depth)
36 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 54W
LP : 59W
Freeze Prevention 141W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Overheat Prevention Device,
Freezing Prevention Device, Fan Rotation Detector
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
N-0531S-OD
NG : 51W
LP : 52W
Freeze Prevention 141W
Anchoring Screws
Outdoor, Wall Mounted
N-0531S (-OD)
Item
Gas Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
(Using the remote controller)
Default Temperature Options
NG : 140,000 btuh, LP : 140,000 btuh
45°F Rise
100-150°F (In 5°F intervals), 160°F (12 Options)
Maximum Performance
Minimum Performance
Performance
NG : 20,000 btuh, LP : 20,000 btuh
5.3 Gal./min.
0.5-6.6 Gal./min.
120, 130, 140
°F (Original is 120 °F )
N-0531S N-0531S-OD
Po wer Vented

6
N-0631S
Indoor/ Outdoor, Wall Mounted
Direct Ignition
15-150 psi
0.5 GPM
23.6"(Height) x 13.8"(Width) x 6.7"(Depth)
41 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 59W
LP : 66W
Freeze Prevention 141W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Overheat Prevention Device, Freezing
Prevention Device, Fan Rotation Detector
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
N-0631S-OD
NG : 46W
LP : 50W
Freeze Prevention 141W
Anchoring Screws
Item
Gas Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
(Using the remote controller)
Default Temperature Options
NG : 180,000 btuh, LP : 180,000 btuh
45°F Rise
100-150°F (In 5°F intervals), 160°F (12 Options)
Maximum Performance
Minimum Performance
Performance
NG : 25,000 btuh, LP : 25,000 btuh
6.3 Gal./min.
0.5-7.1 Gal./min.
120, 130, 140
°F (Original is 120 °F )
N-0631S N-0631S-OD
Outdoor, Wall Mounted
N-0631S (-OD)
Po wer Vented

7
N-0751M
Indoor/ Outdoor, Wall Mounted
Po wer Vented
Direct Ignition
15-150 psi
0.5 GPM
23.6"(Height) x 13.8"(Width) x 9.4"(Depth)
47 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 62W LP : 75W Freeze Prevention 145W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Overheat Prevention Device, Freezing
Prevention Device, Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
45°F Rise 7.5 Gal./min.
0.5-9.8 Gal./min.
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)
Maximum Performance
199,900 btuh
199,900 btuh
Minimum Performance
12,000 btuh
12,000 btuh
N-0751M

8
N-0751M-DV
N-0751M-DV
Indoor, Wall Mounted
Po wer Vented
Direct Ignition
15-150 psi
0.5 GPM
24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
54 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 85W LP : 100W Freeze Prevention 161W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Overheat Prevention Device, Freezing
Prevention Device, Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
45°F Rise 7.5 Gal./min.
0.5-9.8 Gal./min.
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)
Maximum Performance
199,900 btuh
199,900 btuh
Minimum Performance
12,000 btuh
12,000 btuh

9
Specication
N-0751M-OD
Outdoor, Wall Mounted
Power Vented
Direct Ignition
15-150 psi
0.5 GPM
23.6"(Height) x 13.8"(Width) x 9.4"(Depth)
47 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 64W LP : 77W Freeze Prevention 145W
Zincied Steel Plate/Polyester Coating
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Overheat Prevention Device, Freezing
Prevention Device, Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
45°F Rise 7.5 Gal./min.
0.5-9.8 Gal./min.
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)
Maximum Performance
199,900 btuh
199,900 btuh
Minimum Performance
12,000 btuh
12,000 btuh
N-0751M-OD

10
Specication
N-0751M-DVC
Indoor, Wall Mounted
Po wer Vented
Direct Ignition
15-150 psi
0.5 GPM
23.6"(Height) x 13.8"(Width) x 10.2"(Depth)
55 lbs.
0.2 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 108W LP : 96W Freeze Prevention 161W
Zincied Steel Plate/Polyester Coating
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Lightning Protection
Device (ZNR), Electric Leakage Prevention Device
(GFCI), Overheat Prevention Device, Freezing
Prevention Device, Fan Rotation Detector
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Po wer Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
.nim/.laG5.7esiRF°54
0.5-9.8 Gal./min.
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)
Maximum Performance
199,900 btuh
199,900 btuh
Minimum Performance
11,000 btuh
11,000 btuh
N-0751M-DVC

11
N-0931M
N-0931M
Indoor/ Outdoor, Wall Mounted
Power Vented
Direct Ignition
15-150 psi
0.5 GPM
24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
62 lbs.
0.3 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 115W LP : 115W Freeze Prevention 250W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Pressure Relief Valve,
Lightning Protection Device (ZNR), Overheat
Prevention Device, Freezing Prevention Device,
Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
.nim/.laG3.9esiRF°54
0.5-11.1 Gal./min.
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)
Maximum Performance
250,000 btuh
250,000 btuh
Minimum Performance
11,000 btuh
11,000 btuh

12
N-0931M-DV
N-0931M-DV
Indoor Wall Mounted
Po wer Vented
Direct Ignition
15-150 psi
0.5 GPM
24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
62 lbs.
0.3 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 115W LP : 120W Freeze Prevention 250W
Stainless Steel
Copper Sheeting, Copper Tubing
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
.nim/.laG3.9esiRF°54
0.5-11.1 Gal./min.
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)
Maximum Performance
250,000 btuh
250,000 btuh
Minimum Performance
11,000 btuh
11,000 btuh
Flame Rod, Thermal Fuse, Pressure Relief Valve,
Lightning Protection Device (ZNR), Overheat
Prevention Device, Freezing Prevention Device,
Fan Rotation Detector

13
N-0931M-OD
N-0931M-OD
Outdoor, Wall Mounted
Po wer Vented
Direct Ignition
15-150 psi
0.5 GPM
24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
62 lbs.
0.3 Gallon
3/4"
3/4"
3/4"
120 VAC (60Hz)
NG : 90W LP : 95W Freeze Prevention 250W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Pressure Relief Valve,
Lightning Protection Device (ZNR), Overheat
Prevention Device, Freezing Prevention Device,
Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
.nim/.laG3.9esiRF°54
0.5-11.1 Gal./min.
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)
Maximum Performance
250,000 btuh
250,000 btuh
Minimum Performance
11,000 btuh
11,000 btuh

14
N-0841MC
Power Vented
Direct Ignition
15-150 psi
0.5 GPM
24.4"(Height) x 18.4"(Width) x 9.4"(Depth)
73 lbs.
0.5 Gallon
NPT 3/4"
NPT 3/4"
NPT 3/4"
120 VAC (60Hz)
NG : 106W LP : 109W
Freeze Prevention 213W
Stainless Steel
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Pressure Relief Valve,
Lightning Protection Device (ZNR),
Overheat Prevention Device, Freezing Prevention Device,
Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
First Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
.nim/.laG4.8esiRF°54
0.5-11.1 Gal./min.
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)
Maximum Performance
199,900 btuh
199,900 btuh
Minimum Performance
11,000 btuh
11,000 btuh
1/2" Threaded
Condensate Drain
Stainless Steel Sheeting, Stainless Steel Tubing
Secondary Heat Exchanger
N-0841MC-DV
Indoor/ Outdoor, Wall Mounted
Indoor, Wall Mounted
NG : 115W LP : 120W
Freeze Prevention 213W
N-0841MC (-DV)

15
N-1321M-ASME
N-1321M-ASME
Indoor/ Outdoor, Wall Mounted
Power Vented
Direct Ignition
15-150 psi
0.7 GPM
29.7"(Height) x 19.1"(Width) x 11.8"(Depth)
105 lbs.
0.6 Gallon
1"
1"
3/4"
120 VAC (60Hz)
NG : 137W LP : 142W Freeze Prevention 371W
Stainless Steel
Copper Sheeting, Copper Tubing
Flame Rod, Thermal Fuse, Pressure Relief Valve,
Lightning Protection Device (ZNR), Overheat
Prevention Device, Freezing Prevention Device,
Fan Rotation Detector
Remote Controller, Remote Controller Cord,
Anchoring Screws
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Minimum Flow Rate
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Connection Sizes
Power Supply
Materials
Water Inlet
Hot Water Outlet
Gas Inlet
Supply
Consumption
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Maximum Hot Water Capacity
Capacity Range
Temperature Settings
Default Temperature Options
NG
LP
13.2 Gal./min.esiRF°54
0.7-13.2 Gal./min.
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)
Maximum Performance
380,000 btuh
380,000 btuh
Minimum Performance
22,500 btuh
22,500 btuh
Stainless Steel

16
F46.pmetretawtelnI]llaF/gnirpS[F64.pmetretawtelnI]retniW[ [Summer] Inlet water temp. 82 F
80
0 1234567 89101112
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
01234567891011
90
100
110
120
130
140
150
160
170
180
Set temperature ( F)
Flow Rate (GPM)
Hot Water Supply Capabillities
Hot Water Temperature ( F)
Hot Water Flow Rate (gal/min)
[Winter] Inlet water temp. 46 F
[Spring/Fall] Inlet water temp. 64 F [Summer] Inlet water temp. 82 F
80
0 12345678910
90
100
110
120
130
140
150
160
170
180
Hot Water Temperature ( F)
Hot Water Flow Rate (gal/min)
Hot Water Temperature ( F)
Hot Water Flow Rate (gal/min)
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
N-0751M (-DV, -OD, -DVC)
N-0631S (-OD)
F46.pmetretawtelnI]llaF/gnirpS[F64.pmetretawtelnI]retniW[ [Summer] Inlet water temp. 82 F
80
0 1234567 89101112
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
01234567891011
90
100
110
120
130
140
150
160
170
180
Set temperature ( F)
Flow Rate (GPM)
N-0931M (-DV, -OD)
N-0531S (-OD)
F46.pmetretawtelnI]llaF/gnirpS[F64.pmetretawtelnI]retniW[ [Summer] Inlet water temp. 82 F
Set temperature ( F) Set temperature ( F) Set temperature ( F)
80
012345 678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
01 2345 678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
80
01 2345 678
90
100
110
120
130
140
150
160
170
180
Flow Rate (GPM)
F46.pmetretawtelnI]llaF/gnirpS[F64.pmetretawtelnI]retniW[ [Summer] Inlet water temp. 82 F
80
0 1234567 89101112
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
01234567891011
90
100
110
120
130
140
150
160
170
180
Set temperature ( F)
Flow Rate (GPM)
N-0841MC (-DV)

17
Pressure Loss Characteristics
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)
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
Pressure Loss (psi)
0
10
20
30
40
50
60
Ft of Head
Flow Rate (gpm)
F46.pmetretawtelnI]llaF/gnirpS[F64.pmetretawtelnI]retniW[ [Summer] Inlet water temp. 82 F
N-1321M-ASME
Flow Rate (GPM) Flow Rate (GPM) Flow Rate (GPM)
Set temperature ( F)
Set temperature ( F)
Set temperature ( F)

18
Flow rates shown will vary slightly depending on the incoming water temperature
and the setting temperature on the remote controller.
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:
145 F or higher
Bypass Open
Set temperature:
140 F or less
N-0751M (-DV, -OD, -DVC)
Flow rates shown will vary slightly depending on the incoming water temperature
and the setting temperature on the remote controller.
N-0931M (-DV, -OD)
Bypass Close
Set temperature:
145 F or higher
(Storage Tank Setting w/System
Controller : 170 -180 F)
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
Bypass Open
Set temperature:
140 F or less
(Storage Tank Setting w/System
Controller : 160 F or less)

19
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
10
20
30
40
50
60
Set temperature: 135°F or higher
(Storage Tank Setting w/ System
Controller: 170~180°F)
Set temperature: 130 °F or less
(Storage Tank Setting w/ System
Controller: 160 °F or less)
N-0841MC (-DV)
Set temperature: 145°F or higher
(Storage Tank Setting w/ System
Controller: 170~180°F)
Set temperature: 140°F or less
(Storage Tank Setting w/ System
Controller: 160°F or less)
Ft of Head
Flow Rate (GPM)
Pressure Loss (psi)
N-1321M-ASME
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

20
3. Dimensions
N-0531S
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