Noritz NH-2001- DV User manual

1
NORITZ America Corporation
GAS-FIRED DIRECT VENT BOILER
NH-2001- DV
NH-1501- DV
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: January, 2007
Contents
Important Safety Information ....................................................................................................2
1. Product Features ................................................................................................................ 3
2. Specifications/Performance Table ...................................................................................... 4
3. Dimensions ......................................................................................................................... 6
4. Components ....................................................................................................................... 7
5. Operating Principle ............................................................................................................. 9
6. Operation Flow Chart ......................................................................................................... 11
7. Wiring Diagram ................................................................................................................... 13
8. Troubleshooting .................................................................................................................. 15
•Error Codes and Checkpoints ......................................................................................... 15
• Checkpoints .................................................................................................................... 16
•Error Descriptions and How to Reset.............................................................................. 17
•Operation Panel (Remote Controller) ............................................................................. 20
•Displaying Maintenance Monitors on the Operation Panel (Remote Controller) ............ 20
•Maintenance Monitor List ................................................................................................ 21
• Circuit Board Replacement ............................................................................................. 22
• When Changing the Fan Motor ....................................................................................... 23
• Gas Line Requirements .................................................................................................. 24
• Gas Line Sizing Charts ................................................................................................... 25
• Manifold Gas Pressure Adjustment ................................................................................ 26
•Periodic Inspection.......................................................................................................... 27
•Changing Boiler Settings ................................................................................................ 29
• Installations at Elevations Above 2,000 ft. ..................................................................... 30
•Emergency operation procedure..................................................................................... 30
9. Installation Check ............................................................................................................... 31
WS-06-9018

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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
•Wear 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
Parts List for service on this unit. Use appropriate tools.
•Modification 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.
•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
Confirm that there are no gas, water, or exhaust leaks regardless of whether the
service performed could have caused them.
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.
•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
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.

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1. Product Features
1. An external controller is unnecessary in a basic system.
An external zone controller is unnecessary for the indirect tank (PRIORITY1) and heating systems
(PRIORITY 2) which do not use multiple zones.
The boiler has two T-T connections and two circulator output terminals.
2. Dual temperature control
The hot water supply temperature can be set between 140°F-180°F.
It can be customized for PRIORITY1 and PRIORITY2.
3. Flow switch activation
The boiler is equipped with a water flow switch which prevents the boiler from firing when little or no
flow is circulating through the heat exchanger.
Should the circulator, zone valve, etc. fail, the flow switch will also prevent damage to the heat
exchanger.
4. Freeze prevention
Freezing within the boiler caused by a drop in temperature at the installation site or a backflow of
cold air from the outdoors is prevented with the on-board freeze prevention control.
*Refer to the "Installation and Instruction Manual" for limitations on this control.

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2. Specifications/Performance Table
Specification
NH-1501-DV
Indoor Wall Hanging
Direct Vent / Sealed Combustion
Closed type hot-water circulation method
Direct Ignition
15-150 psi
30 psi
24.2"(Height) x 18.3"(Width) x 9.4"(Depth)
65.3 lbs.
0.4 Gallon
1 "
1"
3/4"
120 VAC (60Hz)
NG : 97W LP : 111W
Zincified 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,
Boil-dry Safety Device, Boil-dry Protection Device, Overcurrent Protection Device
Pressure & Temperature Gauge, Safety Relief Valve (valve, fitting, and gasket),
Anchoring Screws, Terminals
Performance
Item
Model Name
Type
Ignition
Operating Pressure
Safety valve setting pressure
Dimensions
Weight
Water Holding Capacity
Accessories
Installation
Air Supply/Exhaust
Heating method
Connection Sizes
Power Supply
Materials
Supply
Return
Gas Inlet
Supply
Consumption (*)
Casing
Flue Collar
Heat Exchanger
Safety Devices
Item
Gas
Consumption
Standard output
Temperature Settings
NG
LP
140-170°F (In 5°F intervals), 176, 180°F (9 Options)
NH-2001-DV
199,900 btuh
NH-1501-DV
150,000 btuh
4-17 GPM (bypass minimum-flow rate: 2.5GPM)Amount of boiler water used
NH-2001-DV
55,500 btuh 55,500 btuh
Maximum Performance
Minimum Performance
Maximum Performance
Minimum Performance
199,900 btuh 150,000 btuh
55,500 btuh 55,500 btuh
60-80°C (In 5°C intervals), 83°C (6 Options)
45,500-163,100 btuh 45,500-122,400 btuh
Fahrenheit
Centigrade
NG : 93W LP : 93W
AFUE NG
LP
82.7% 83.0%
83.0% 82.8%
*The values listed are for the boiler only.
The maximum current draw by the unit with 2 pumps connected will be 6 amperes or less.

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Heating load - Temperature Specification
Pressure Loss Characteristics
The total flow rate of the heating circuit should be no less than 4 gpm (15 L/min.) and no greater
than 17 gpm (65 L/min.).
Flow rate (GPM)
0 3.8 7.6 11.4 15.2 19.0 22.8 26.6 30.4 34.2 38.0 41.8 45.6 49.4 53.2 57.0 60.8 64.6
Flow rate (L/min)
Setting Temp. +13°F
Note) Maximum temperature is 188°F (87°C)
Proportional control
Setting Temp. Setting Temp.
Temperature
(approximately)
Setting Temp. -18°F
Setting Temp. +7°C
Setting Temp. -10°C
NH-1501-DV
NH-2001-DV
45,500 btu/h
45,500 btu/h
122,400 btu/h
163,100 btu/h
(approximately)
Heating load

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3. Dimensions
WIRING THROUGHWAYS
WATER SUPPLY(1")
GAS INLET(3/4")
WATER RETURN(1")
"14.2
"10.6
"8.9
"2.4
"6.8
"6.8
"5
"3.2
"6.4
"5.8
"4.3
"4.6
(WATER DRAIN VALVE)
"26.2
"
6.7
"
5.5
"
3.9
"
2.8
"
1.4
"
6.7
"
5.5
"
3.9
"
2.8
"
1.4
17.7"
(WATER FILTER)
BOTTOM OF CASE
PRESSURE RELIEF VALVE
WATER DRAIN VALVE
WIRING THROUGHWAYS
WATER SUPPLY
GAS INLET
WATER RETURN
BOTTOM OF CASE
"7
"5.7
"0.4
"9.4
"3.7
"0.4
"1.6
OPERATION
PANEL
AIR INLET FLUE COLLAR
9.1"
"4
"24.2
18.3"
"4
5.9"
1.7"
"2.2 "3.4
"2.6
(VIEW FROM TOP)

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4. Components
Transformer
Heat Exchanger
Circuit Board SC
Circuit Board
Heat Exchanger Thermistor
Water Return Thermistor
Water Supply Thermistor
Water Flow Switch
Gas Valve Mechanism
Air Inlet Exhaust Flue
Air Inlet Thermistor
Flame Rod
Thermal Fuse
Ignition Electrode
Manifold
Safety Relief Valve
High Limit Switch
Igniter
Fan Motor
Junction Box
(Inlet Filter)
Drain Plug Water Drain Plug
Gas Inlet
Water Supply
Water Return

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Operation Panel (RC-7648M)
For changing the set
temperature and
performing various
settings.
Setting Buttons
Temperature Setting
(Ex.: 180°F)
A number will flash if
a failure occurs.
Burner On Indicator
When burning, the indicator is lit.
•The indicator will flash when
the temperature of
PRIORITY 1 (Indirect tank
use) is displayed.
•The indicator is lit during
PRIORITY 1 (Indirect tank
use) operation.
PRIORITY 1 Indicator
Error Code
Power On/Off Button
For turning the
boiler on and off.
For setting the temperature
of PRIORITY 1.
PRIORITY 1 Button
For setting the temperature
of PRIORITY 2.
PRIORITY 2 Button
For changing the maximum
temperature setting of
PRIORITY 1.
Maximum Temperature
Setting Button
* Before use, remove the protective sheet from the remote controller surface.
• The indicator will flash
when the temperature
of PRIORITY 2 (Heating
use) is displayed.
•The indicator is lit
during PRIORITY 2
( Heating use )
operation.
PRIORITY 2 Indicator

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5. Operating Principle
T-T connection
Contact for Lamp
Circulator outputs,
Air inlet thermistor
Controller
SC
Controller
Rotational
frequency sensor
Fan motor
Air supply
AC 120V
Transformer
Gas solenoid valve-2
Gas solenoid valve-1
Gas solenoid valve-3
Water supply thermistor
Drain plug
Supply Gas Return
Inlet filter
Water drain plug
Water flow
switch
Primary gas
valve
Gas proportioning
valve
Burner
Flame rod
Ignition plug
Igniter
Over heat prevention
device (Thermal fuse)
Water return thermistor
Heat exchanger
thermistor
Exhaust
High limit switch
Safety relief
valve

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< How to Use, NH-2001-DV / NH-1501-DV >
1. Normal Operation (Priority1 or Priority2)
1. Turn on the power by pressing the "POWER" button on the operation panel (remote controller).
(Power indicator lit.)
2. When the Operation switch of the "Indirect tank" or "Room thermostat" is turned ON (Priority1 or Priority2 calls for
heat), the boiler supplies power to the Priority1 or Priority2 circulator.
3. When the water flow switch is ON and water supply thermistor detection temperature is lower than combustion
start temperature, the fan will initiate and pre-purge any residual combustible gas in the combustion chamber,
and then the igniter begins to spark. Finally, the gas valves open, and burner is ignited by the spark.
4. When the flame rod detects a flame, the igniter stops sparking.
5. The computer will then control the gas and fan to maintain the supply temperature set on the operation panel
(According to "Priority1 temperature setting" or "Priority2 temperature setting").
The temperature can be adjusted using the "Priority1" button or "Priority2" button on the operation panel.
* When "Priority1" and "Priority2" both call for heat, the boiler gives priority to the "Priority1" circuit.
* When the heating load is too small, the burner is controlled ON/OFF.
6. When the Operation switch of the "Indirect tank" or "Room thermostat" is turned OFF (Priority1 or Priority2 no
longer calls for heat), the gas valve will close and the burner flame will go out. After the post purge removes
residual gas from the combustion chamber and post circulation removes the residual heat from the heat
exchanger, the appliance stops.
7. When the boiler is not being used for an extended period of time, turn off the power by pressing the "POWER"
button on the operation panel. (Power indicator OFF)
2. Error Codes
If the flame rod does not detect a flame, or if the high limit switch has been triggered, the gas valve will close, the
flame will go out, and an error code will flash on the operation panel. In order to reset the boiler and remove the
error code, turn the power off by pressing the "POWER" button on the operation panel, and then press it again to
turn the boiler back on. If the problem requires service ( the thermal fuse is triggered, etc.) the gas valves will stay
closed and resetting the appliance will not eliminate the error code. If this is the case, the boiler must be serviced
(repaired) before it will work again.
3. Miscellaneous
If the boiler will not be used for a long period of time, turn off the power, and close the manual gas valves on the
supply line.