Noritz NR71-SV, NR66-SV, NR71-OD, NR66-OD Installation Manual

Installation Manual

NORITZ AMERICA
CORPORATION

Canada

TANKLESS GAS WATER HEATER

NR71-SV, NR66-SV (Indoor/Outdoor Installation)
NR71-OD, NR66-OD (Outdoor Installation)

Potential dangers from accidents during installation and use are divided into the following three
categories. Closely observe these warnings, they are critical to your safety.

DANGER indicates an imminently hazardous situation which,

DANGER

WARNING

if not avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation which,

if not avoided, could result in death or serious injury.

CAUTION

CAUTION indicates a potentially hazardous situation which,
if not avoided, may result in minor or moderate injury.

WARNING: If the information in this manual is not followed exactly, a fire or explosion may result

causing property damage, personal injury or death.

Prohibited

Disconnect
Power

Ground

Be sure to do

CAUTION

Requests to Installers

• In order to use the water heater safely, read this installation manual carefully, and follow the
installation instructions.

• Failures and damage caused by erroneous work or work not as instructed in this manual are not
covered by the warranty.

• Check that the installation was done properly in accordance with this Installation Manual upon
completion.

•

After completing installation, please either place this Installation Manual in a plastic pouch and
attach it to the side of the water heater (or the inside of the pipe cover or recess box if applicable),
or hand it to the customer to retain for future reference. Also, be sure to fill in all of the required
items on the warranty and to hand the warranty to the customer along with the Owner's Guide.

CERTIFIED

R

KS-09-0007

Rev. 10/09

FOR USE IN RESIDENTIAL, COMMERCIAL, OR MANUFACTURED HOME
APPLICATIONS.

Installation must conform with local codes, or in the absence of local codes, the
National Fuel Gas Code, ANSI Z223.1/NFPA 54- latest edition and/or CSA
B149.1, Natural Gas and Propane Installation Code (NSCNGPIC).

When applicable, installation must conform with the Manufactured Home Construc­tion and Safety Standard, Title 24 CFR, Part 3280 or the Canadian Standard CAN/
CSA-Z240 MH Mobile Homes, Series M86. (NR71-OD, NR66-OD only)

Noritz America reserves the right to discontinue, or change at any
time, the designs and/or specifications of its products without notice.

(NR71-OD, NR66-OD only)

1.

Included Accessories

The following accessories are included with the unit.
Check for any missing items before starting installation.

Part Shape Q’ty

Tapping Screw

(NR71-SV, NR66-SV)

Owner's Guide, Warranty,

Installation Manual

(this document)

2.

Optional Accessories

Remote Controller

(See p. 22)

Outdoor Vent Cap

VC4-1 (for NR71-SV)

VC3 (for NR66-SV)

Cross Recess

5

1

each

1

1

Head Screw

(NR71-OD, NR66-OD)

Power Cord

(NR71-SV, NR66-SV)

The accessories listed below are not
included with the units, but may be necessary
for installation.

Remote Controller

Cord 3m (10ft)

Remote Controller

Cord 8m (26ft)

Q’tyShapePart

3

1

Q’tyShapePartPart Shape Q’ty

1

1

Isolation Valves

(includes pressure

relief valve)

Pipe Cover (PC1S)

(NR71-SV, NR71-OD)

Remote Controller

Outdoor

Junction Box

1

Recess Box

1

1

RB-600

(for NR71-OD only)

RB-500

(for NR66-OD only)

1

2

Before Installation

3.

DANGER

Checkup

• Check the fixing brackets and vent pipe yearly for damage or wear. Replace if necessary.

WARNING

Check the Gas

• Check that the rating plate indicates the
correct type of gas.

• Check that the gas supply line is sized for
180,000 Btuh for NR71-SV, NR71-OD.

(140,000 Btuh for NR66-SV, NR66-OD.)

Check the Power

• The power supply required is 120VAC, at 60Hz.
May result in fire or electric shock.

Use Extreme Caution if Using With a Solar Pre-Heater

• Using this unit with a solar pre-heater can lead to unpredictable output temperatures and

possibly scalding. If absolutely necessary, use mixing valves to ensure output temperatures do

not get to scalding levels.

Ex. For Natural Gas NR71-SV

NR71-SV

180,000 BTU

25,000 BTU

177

670

4.0

0.55 2.25

15

10.5

150

2

CAUTION

Do Not Use Equipment for Purposes Other Than Those Specified

• Do not use for other than increasing the temperature of the water supply, as unexpected accidents
may occur as a result.

Check Water Supply Quality

• If the water supply is in excess of 12 grains per gallon (200 mg/L) of hardness, acidic or otherwise
impure, treat the water with approved methods in order to ensure full warranty coverage.

3

Choosing Installation Site

4.

* Locate the appliance in an area where leakage from the unit or connections will not result in damage

to the area adjacent to the appliance or to the lower floors of the structure. When such locations
cannot be avoided, it is recommended that a suitable drain pan, adequately drained, be installed
under the appliance. The pan must not restrict combustion air flow.

DANGER

•

Install the exhaust vent (terminal) so that there are no obstacles around the termination and so that
exhaust can't accumulate. Do not enclose the termination with corrugated metal or other materials.

• Model NR71-OD, NR66-OD is for outdoor installation only. Never install it indoors.
Do not enclose the termination with corrugated metal or other materials.

This will cause carbon monoxide poisoning and a potential fire hazard.

WARNING

• Avoid places where fires are common, such as those where gasoline,
benzene and adhesives are handled, or places in which corrosive gases
(ammonia, chlorine, sulfur, ethylene compounds, acids) are present.
Using the incorrect voltage may result in fire or cracking.

Prohibited

• Avoid installation in places where dust or debris will accumulate.

Dust may block the air-supply opening, causing the performance of the
device fan to drop and incomplete combustion to occur as a result.

• Avoid installation in places where special chemical agents
(e.g., hair spray or spray detergent) are used.

Ignition failures and malfunction may occur as a result.

[NR71-SV, NR66-SV only]

• Carbon Monoxide Poisoning Hazard. Do not install this water heater in a
mobile home, recreation vehicle or on a boat.

[NR71-OD, NR66-OD only]

• Carbon Monoxide Poisoning Hazard. Do not install this water heater in a
recreational vehicle or on a boat.

CAUTION

• Install the water heater in a location where it is free from obstacles and stagnant air.

• Consult with the customer concerning the location of installation.

• Do not install the water heater near staircases or emergency exits.

• Do not install the water heater where the exhaust will blow on outer walls or material
not resistant to heat. Also consider the surrounding trees and animals.

The heat and moisture from the water heater may cause discoloration of walls and
resinous materials, or corrosion of aluminum materials.

• Do not locate the vent termination directed towards a window or any other structure
which has glass or wired glass facing the termination.

4

CAUTION

•

Avoid installation above gas ranges or stoves. (NR71-SV, NR66-SV)

• Avoid installation between the kitchen fan and stove. If oily
fumes or a large amount of steam are present in the installation
location, take measures to prevent the fumes and steam from
entering in the equipment. (

• Install in a location where the exhaust gas flow will not be
affected by fans or range hoods.

• Take care that noise and exhaust gas will not affect neighbors.
Avoid installation on common walls as the unit will make some
operational noises while it is running.

• Make sure that the location allows installation of the exhaust
vent as specified.

• For outdoor installation, use the outdoor vent cap.

(NR71-SV, NR66-SV)

If it is necessary to vent above the roof line in an outdoor instal­lation, use high temperature sealant around the flue collar for
rain protection.

• Avoid installation where the unit will be exposed to excessive
winds.

NR71-SV, NR66-SV

)

Prohibited

Be sure to do

Prohibited

• Before installing, make sure that the vent termination (or the
vent cap in an outdoor installation) will have the proper clear­ances according to the National Fuel Gas Code (ANSI Z223.1).

State of California: The water heater must be braced, anchored or strapped to avoid moving during an
earthquake. Contact local utilities for code requirements in your area or call: 1-866-766-7489 and request
instructions.

The Commonwealth of Massachusetts:

1) The outdoor units (OD) can only be used if they are for summer use only.

2) The water heater can be used for hot water only and not in a combination of domestic and space
heating.

For Venting Manufacturers Requirements, see websites or phone numbers listed below:
Noritz N-Vent www.noritz.com

5

5. Installation Clearances

WARNING

Before installing, check for the following:

Install in accordance with relevant building and mechanical codes, as well as any local, state or
national regulations, or in the absence of local and state codes, to the National Fuel Gas Code ANSI
Z223.1/NFPA 54 – latest edition. In Canada, see NSCNGPIC for detailed requirements.

[ For NR71-SV, NR66-SV ]

Item

• Maintain the following clearance from
both combustible and non-combustible
materials.

From Heater

Required Clearances

• If the unit will be installed in the vicinity of a
permanent kitchen range or stove that has
the possibility of generating steam that
contains fats or oils, use a dividing plate or
other measure to ensure that the unit is not
exposed to air containing such impurities.

* The dividing plate should be of noncombust-

ible material of a width greater than the

Cooking Equipment

water heater.

Check Illustration

Exhaust hood

Dividing plate

Range

300mm (12") or more
(Indoor)
900mm (36") or more
(Outdoor)

100mm (4") or more
(Indoor)
600mm (24") or more
(Outdoor)

50mm (2")

150mm (6") or more (Outdoor)

or more (Indoor)

Water
heater

• If possible, leave 200mm (8") or more on
either side of the unit to facilitate inspection.

• If possible, leave 600mm (24") or more in
front of the unit to facilitate maintenance
and service if necessary.

• If possible, leave 75mm (3") or more above
and below the vent pipe to facilitate inspec­tion and repair if necessary.

repair/inspection

Securing of space for

6

200mm
(8") or
more

600mm
(24") or
more

75mm (3") or more

75mm (3") or more

200mm
(8") or
more

[ For NR71-OD, NR66-OD ]

Item Check

• Maintain the following clearance from both combustible
and non-combustible materials.

*( ) indicates the distance when installing a heat insulat-

ing board (incombustible material other than metal, with
thickness of 2.5mm (0.1") or more) or "section of build­ing effectively finished with incombustible material."
Note, however, that combustion failure may occur to the
unit as exhaust gas reflects from the wall. Provide clear­ance of 600mm (24") or more in the front of the unit to
facilitate inspection and repair.

Required Clearances From Heater

• When installing the unit in a common side corridor, pro­vide a clearance of 1175mm (47") or more in front of the
unit.

• Set the bottom edge of the exhaust port about 2100mm
(84") from the corridor floor.

Illustration

600mm (24")
(300mm (12"))

or more

combustible

10mm (0.4")
or more

combustible

combustible

150mm (6") or more

Handrail

combustible

900mm (36")
or more

150mm (6")
or more

combustible

1175mm (47")
or more
about

2100mm (84")
common side

corridor

• When installing the unit on a balcony, etc., secure an
evacuation route of 600mm (24") or more in width.

• Provide clearance of 600mm (24") or more in front of the
unit to facilitate inspection and repair. Do install the unit
such as the wall of the second floor where the unit is out

Surrounding the area of installation

of reach.

600mm (24") or more

Handrail

balcony, etc.

7

Clearance Requirements from Vent Terminations to Building Openings

* All clearance requirements are in accordance with ANSI Z21.10.3 and the National Fuel Gas Code,

ANSI Z223.1 and in Canada, in accordance with NSCNGPIC.

A=

B=

C=

D=

E=

F=

G=
H=

I=

J=

K=

L=

M=

Clearance

Above grade, veranda, porch, deck,

or balcony
Window or door that may be opened

Permanently closed window
Vertical clearance to ventilated soffit

located above the terminal within a
horizontal distance of 0.6m
the center of the terminal

Unventilated soffit
Outside corner
Inside corner
Each side of center line extended

above meter/regulator assembly
Service regulator vent outlet
Nonmechanical air supply inlet or

combustion air inlet to any other
appliance

Mechanical air supply inlet
Above paved sidewalk or paved

driveway located on public property
Under veranda, porch, deck, or

balcony

(2')

from

Vent Terminal

Air Supply Inlet

Indoor Installation

(See p.9)

1.2m (4') below or to the side of

opening, or 0.3m (1') above opening

[900mm (36")]

*

*

*
*
*

0.9m (3') within a height 4.5m (15')
above meter/regulator assembly

0.9m (3')

1.2m (4') below or to the side of

opening, or 0.3m (1') above opening

[900mm (36")]

0.9m (3') above if within
3m (10') [1.8m (6')]

[2.1m *** (7' ***)]

*[300mm (12") - Canada Only]**** *[300mm (12") - Canada Only]****

Outdoor Installation

300mm (12") [300mm (12")]300mm (12") [300mm (12")]

300mm (12") [900mm (36")]

0.9m (3') within a height 4.5m (15')
above meter/regulator assembly

300mm (12") [900mm (36")]

0.9m (3') above if within
3m (10') [1.8m (6')]

Area Where Terminal
is Not Permitted

(See p.10)

*

*

*
*
*

0.9m (3')

[2.1m *** (7' ***)]

[ ]= indicates clearances required in Canada
* Maintain clearances in accordance with local installation codes and the requirements of the gas supplier
*** A vent shall not terminate directly above a sidewalk or paved driveway that is located between two
single family dwellings and serves both dwellings.
**** Permitted only if veranda,porch,deck,or balcony is fully open on a minimum of two sides beneath the floor.

8

Clearance Requirements from Vent Terminations to Building Openings

* All clearance requirements are in accordance with ANSI Z21.10.3 and the National Fuel Gas Code,

ANSI Z223.1 and in Canada, in accordance with NSCNGPIC.

[ For NR71-SV, NR66-SV ]

Maintain the following clearances to any

opening in any building:

• 1.2m (4') below, 1.2m (4') horizontally from,
or 0.3m (1') above any door, operable
window, or gravity air inlet into any building.

0.9m (3') above any forced air inlet within
3m (10').

stalled Indoors

Vent Clearances When Heater is In-

• 0.3m (1') below, 0.3m (1') horizontally from,
or 0.3m (1') above any door, operable
window, or gravity air inlet into any building.

0.9m (3') above any forced air inlet within
3m (10').

Illustration

1.2m (4')

1.2m (4')

0.3m (1')

0.9m (3')

0.3m (1')

0.3m (1')

0.3m (1')

0.9m (3')

Noritz vent cap

stalled Outdoors With a Vent Cap

Vent Clearances When Heater is In-

* For Installations in Canada, clearances are as follows: To windows, doors, & gravity air inlets: 900mm (36").

To forced air inlets: 1.8m (6'). These clearance requirements hold true for all of the above situations: Indoor,
Outdoor w/vent cap.

VC4-1 (for NR71-SV)
VC3 (for NR66-SV)

9

[ For NR71-OD, NR66-OD ]

Maintain the following clearances to any

opening in any building:

• 0.3m (1') below, 0.3m (1') horizontally from,
or 0.3m (1') above any door, operable win­dow, or gravity air inlet into any building.

0.9m (3') above any forced air inlet within 3m
(10').

into Any Building

Outdoor Clearances to Opening

• 0.3m (1') below, 0.3m (1') horizontally from,
or 0.3m (1') above any door, operable
window, or gravity air inlet into any building.

0.9m (3') above any forced air inlet within
3m (10').

Illustration

0.3m (1')

0.3m (1')

0.3m (1')

0.9m (3')

0.3m

0.3m (1')

(1')

0.3m (1')

0.9m (3')

Vent Clearances When Heater is

Installed in a Recess Box (NR71-OD only)

(recess box installation with cover removed)

* For Installations in Canada, clearances are as follows: To windows, doors, & gravity air inlets: 900mm (36").

To forced air inlets: 1.8m (6').

10

6. Installation

Securing to the wall

• The weight of the device will be applied to the wall. If the strength of the wall is not suffi­cient, reinforcement must be done to prevent the transfer of vibration.

• Do not drop or apply unnecessary force to the device when installing. Internal parts may

Be sure to do

be damaged and may become highly dangerous.

• Install the unit on a vertical wall and ensure that it is level.

Item

• When installing with bare hands, take caution to
not inflict injury.

• Be careful not to hit electrical wiring, gas, or water
piping while drilling holes.

1. Drill a single screw hole, making sure to hit a stud.

2. Insert and tighten the screw and hang the unit by
the upper wall mounting bracket.

Locating Screw Holes

3. Determine the positions for the remaining four screws
(two for the top bracket and two for the bottom), and
remove the unit.

4. Drill holes for the remaining four screws.

5. Hang the unit again by the first screw, and then
insert and tighten the remaining four screws.

6. Take waterproofing measures so that water does

not enter the building from screws mounting the

Mounting

device.

Check

CAUTION

Illustration

Location of Screw Hole

Mounting Bracket
(upper)

Locating Screw Holes

Tapping Screw

• Make sure the unit is installed securely so that it will

not fall or move due to vibrations or earthquakes.

Structure

• If this water heater is being installed at an elevation of
610m. (2,000') or higher, disconnect the connector la­beled "High Elevation Disconnect" as illustrated on the
right. This connector is located inside the unit.

• Disconnect power to the water heater before discon­necting this connector. Failure to perform this step will
result in a flashing light on the unit or a "73" code dis­played on the optional remote controller and a cease
in operation. If this occurs, disconnect, then reconnect

Above 610m (2,000').

power to the water heater to reset the system.

Installations at Elevations

DISCONNECT

HIGH ELEVATION

11

Vent Pipe Installation

7.

Be sure to do

( NR71-SV Only, Indoor Installation)

WARNING

CARBON MONOXIDE POISONING
Follow all vent system requirements in accordance with relevant local or state regulation,
or, in the absence of local or state code, in the U.S. to the National Fuel Gas Code ANSI
Z233.1/NFPA 54 – latest edition, and in Canada, in accordance with NSCNGPI.

Vent Piping

• Noritz N-Vent is suggested for the vent system.
If N-Vent is not used, a UL listed category III vent
system must be used.

• Follow the vent pipe manufacturer's installation
instructions.

NR71-SV

Pipe diameter 100mm (4")

No. of Elbows

3 4.5m (15')
2 8.1m (27')
1 11.7m (39')

NR66-SV

Pipe diameter 75mm (3")

No. of Elbows

3 4.5m (15')
2 7.5m (25')
1 10.6m (35')

*Not including the termination.

• Make the vertical section of the exhaust vent
as short as possible.

• Maintain the same vent pipe diameter from the
heater flue to the vent termination.

Max. Straight Vent Length*

Max. Straight Vent Length*

• The first vertical run from the top of the heater
should be no longer than 0.9m (3').

• Make sure vent pipe is gas tight and will not
leak. Use silicon sealant wherever necessary.

• Do not common vent or connect more than
one appliance to this venting system.

•

The total vent length including horizontal & vertical
vent runs should be no less than 0.9m (3').

• Do not store hazardous or flammable sub­stances near the vent termination and check
that the termination is not blocked in any way.

• Steam or condensed water may come out
from the vent termination. Select the location
for the termination so as to prevent injury or
property damage.

• If snow is expected to accumulate, take care
the end of the pipe is not covered with snow or
hit by falling lumps of snow.

•Consult the vent pipe manufacturer's install­ation instructions for chimney connections.

Appliance Adapters

When using a vent system other than N-Vent,
an appliance adapter will be required to properly
connect the vent to this appliance. Consult the
manufacturer's instructions for the proper appli­ance adapter.

Clearances

Manufacturer and Enclosed Unenclosed
Product Hor. Vert. Hor. Vert.

Noritz N-Vent

Clearances vary by manufacturer, refer to the UL
approved clearances when using materials other
than N-Vent.

250mm (10")(sides)
375mm (15")(top)
150mm (6")(bottom)

12

100mm

(4")

25mm

(1")

25mm

(1")

Horizontal Vent Termination

Hanger

Straps

Elbow

Slope vent

Downwards

**0.3m (1') Min. -

Appliance

Adapter*

0.9m (3') Max.

* Adapter not required when
using Noritz N-Vent.

**0.3m (1') minimum recommended,
but not required. Avoid installing
elbow directly on flue.

Vertical Vent Termination

Storm
Collar

Roof
Jack

Hanger

Elbow

**0.3m (1') Min. -

0.9m (3') Max.

Appliance

Adapter*

Strap

Condensation

Drain (Install
According to

Local Codes)

* Adapter not required when
using Noritz N-Vent.

**0.3m (1') minimum recommended,
but not required. Avoid installing
elbow directly on flue.

Wall

Thimble

Firestop/

Rain

Cap

Roof

Flashing

Support

Firestop

Te r mination

•Terminate at least 300mm (12") above
grade or above snow line.

• Terminate at least 2.1m (7') above a pub­lic walkway, 1.8m (6') from the combus­tion air intake of any appliance, and 0.9m
(3') from any other building opening, gas
utility meter, service regulator etc.

• Terminate at least 0.9m (3') above any
forced air inlet within 3m (10'), 1.2m (4')
below, 1.2m (4') horizontally from or 0.3m
(1') above any door, window, or gravity air
inlet into any building per National Fuel Gas
Code ANSI Z223.1/NFPA 54.

• Slope the horizontal vent 1/4" downwards
for every 300m (12") toward the termination.

• Use a condensation drain if necessary.

• In the Commonwealth of Massachusetts
a carbon monoxide detector is required
for all side wall horizontally vented gas
fuel equipment. Please refer to Technical
Bulletin TB 010606 for full installation in­structions.

• Terminate at least 1.8m (6') from the combus­tion air intake of any appliance, and 0.9m (3')
from any other building opening, gas utility
meter, service regulator etc.

• Enclose exterior vent systems below the roof
line to limit condensation and protect against
mechanical failure.

• When the vent penetrates a floor or ceiling and
is not running in a fire rated shaft, a firestop and
support is required.

• When the vent termination is located not less
than 2.4m (8') from a vertical wall or similar ob­struction, terminate above the roof at least 0.6m
(2'), but not more than 1.8m (6'), in accordance
with the National Fuel Gas Code ANSI Z223.1/
NFPA 54.

• Provide vertical support every 3.6m (12') or as
required by the vent pipe manufacturer's in­structions.

• Slope the horizontal vent 1/4" for every 300mm
(12") towards the drain tee.

•A short horizontal section is recommended to
prevent debris from falling into the water heater.

• Install a condensation drain in the horizontal
section of the venting. For installations in tight
spaces where there is not enough room to in­stall two elbows and a horizontal drain tee, a
vertical drain tee may be substituted.

13

Combustion Air

Supply combustion air to the units as per the National Fuel Gas Code, ANSI Z223.1 and
in Canada, in accordance with NSCNGPIC.

• Provide two permanent openings to allow
circulation of combustion air.

• Make each opening 180 square inches if they
provide indoor air, and 100 square inches for
outdoor air.

• If the unit is installed in a mechanical closet,
provide a 600mm (24") clearance in front of
the unit to the door.

• If combustion air will be provided through a
duct, size the duct to provide 60 cubic feet of
fresh air per minute.

225mm

(9")

500mm

(20")

500mm

(20")

225mm

(9")

Openings supplying indoor air

14

Gas Piping

8.

Follow the instructions from the gas supplier.

The appliance and its individual shutoff valve must be disconnected from the gas supply piping system
during any pressure testing of that system at test pressures in excess of 1⁄2 psig (3.5 kPa).
The Appliance must be isolated from the gas supply piping system by closing its individual manual
shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or
less than 1⁄2 psig (3.5 kPa).

The appliance and its gas connections must be leak tested before placing the appliance in operation.
The inlet gas pressure must be within the range specified. This is for the purposes of input adjustment.
In order to choose the proper size for the gas line, consult local codes or the National Fuel Gas Code ANSI

Z223.1.

Gas Pressure

Size the gas line according to total btuh demand
of the building and length from the meter or

Gas Meter

Select a gas meter capable of supplying the entire
btuh demand of all gas appliances in the building.

regulator so that the following supply pressures
are available even at maximum demand:

Natural Gas Supply Pressure

Min. 4" WC
Max. 10.5" WC

LP Gas Supply Pressure

Min. 8" WC
Max. 14" WC

Gas Connection

• Do not use piping with a diameter smaller than
the inlet diameter of the water heater.

• Gas flex lines are not recommended unless they
are rated for 180,000 btuh (NR71-SV, NR71-OD)
or 140,000 btuh (NR66-SV, NR66-OD).

• Install a gas shutoff valve on the supply line.

• Use only approved gas piping materials.

Measuring Gas Pressure

In order to check the gas supply pressure to the unit, a tap is
provided on the gas inlet. Remove the hex head philips
screw from the tap, and connect a manometer using a
silicon tube.

In order to check the gas manifold pressure, a pair of taps
are provided on the gas valve inside the unit.
The pressure can be checked either by removing the hex
head philips screw and connecting a manometer with a
silicon tube, or by removing the 1/8" NPT screw with an allen
wrench and connecting the appropriate pressure gauge.

Noritz Gas Water Heater
(NR71-SV (-OD):180,000 Btuh)
(NR66-SV (-OD):140,000 Btuh)

Outlet E

Section 4

5'

10'

Natural Gas

Meter

**See next page for the pipe capacity charts.

Sample Gas Line

10'

Section 3 Section 2

Outlet D

Outlet C

5' 5'

5'

Gas Fireplace
(25,000 Btuh)

Clothes Dryer
(35,000 Btuh)

5'

Section 1

(50,000 Btuh)

Outlet A

10'

Outlet B

Gas Range Stove

(65,000 Btuh)

Barbecue

10'

5'

Instructions

1. Size each outlet branch starting from the furthest
using the Btuh required and the length from the
meter.

2. Size each section of the main line using the
length to the furthest outlet and the Btuh
required by everything after that section.

Sample Calculation

Outlet A: 45' (Use 50'), 50,000 Btuh requires 1/2"
Outlet B: 40', 65,000 Btuh requires 1/2"
Section 1: 45' (Use 50'), 115,000 Btuh requires 3/4"
Outlet C: 30', 35,000 Btuh requires 1/2"
Section 2: 45' (Use 50'), 150,000 Btuh requires 3/4"
Outlet D: 25' (Use 30'), 25,000 Btuh requires 1/2"
Section 3: 45' (Use 50'), 175,000 Btuh requires 1"
Outlet E: 25' (Use 30'), 180,000 Btuh requires 3/4" (NR71-SV (-OD))
140,000 Btuh requires 3/4" (NR66-SV (-OD))
Section 4: 45' (Use 50'), 355,000 Btuh requires 1-1/4" (NR71-SV (-OD))
315,000 Btuh requires 1-1/4" (NR66-SV (-OD))

15

Natur

Liquified P

Gas Line Sizing for a Noritz Gas Water Heater

Maximum Natur

Pipe
Size

1 1/4"
1 1/2"

2 1/2"

3 1/2"

10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 125'

1/2"

174

3/4"

363

1"

684
1404
2103

4050

2"

6455

3"

11,412
16,709

4"

23,277

Contact the Gas Supplier for Btu/Cubic Ft. of the Supplied Gas. 1000 BTU/Cubic Ft. is a Typical Value

Adapted from UPC 1997

al Gas Delivery Capacity in Cubic Feet per Hour (0.60 Specific Gravity, 0.5" WC Pressure Drop)

Length in Feet

119
249
470

965
1445
2784
4437

7843
11,484
15,998

96
200
377

775
1161
2235
3563

6299
9222

12,847

82
171
323
663

993
1913
3049
5391
7893

10,995

73
152
286
588
880

1696
2703
4778
6995
9745

66
138
259

532
798
1536
2449
4329
6338
8830

61
127
239
490
734

1413
2253

3983
5831
8123

56 53 50 44
118 111 104 93
222 208 197 174
456
683

1315
2096

3705
5425
7557

428

641
1234
1966

3476
5090
7091

404

605
1165
1857
3284
4808
6698

1033
1646
2910
4261
5936

358
536

Maximum Liquified P

Maximum Capacity of Flex TracPipe in Cubic Feet per Hour of Natural Gas

Maximum Capacity of Flex TracPipe in Thousands of Btuh Liquified Petroleum

etroleum (Undiluted) Delivery Capacity in Thousands of Btuh (0.5" WC Pressure Drop)

Pipe

10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 125' 150' 200'

Size

1/2"

275

189

152

129

3/4"

567

393

732
1496
2299
4331

147
269
418
888

2078

232
425
661

1404
3285

315

590
1212
1858
3465

1698

1143
2684

1039
1559
2992

121
218
334
723

191
344
528

1071

1"

2205

1 1/4"

3307

1 1/2"

2"

6221

** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.

Pipe
Size

10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 150' 200'

206

3/4"

1"

383

1 1/4"

614

1 1/2"

1261

2"

2934

Pipe
Size

10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 150' 200'

325

3/4"

1"

605

1 1/4"

971

1 1/2"

1993

2"

4638

** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.
Tr acPipe® is a registered trademark of Omega Flex.

267
504

R

105
188
284
625

1472

166
297
449
988

2327

114
237
448

913
1417
2646

1317

R

2082

1275
2394

94
168
251
559

149
265
397
884

Length in Feet

103
217

196

409

378

834

771

1181
2205

Length in Feet

86
153
227
509

1203

Length in Feet

136
241
359
805

1902

96

80
141
209
471

1114

126
222
330
745

1761

89
185
346

724
1086
2047

75
132
194

440

1042

118
208
307
696

1647

83
173
322
677

1023
1921

78

69

162

146
275

307

567

630

866

976

1606

1811

(0.60 Specific Gravity, 0.5" WC Pressure Drop)

71
125
181
415
983

112
197
286
656

1554

67
118
171
393
933

106
186
270

621

1475

63

55

132

112

252

213

511

440
675

787

1496

1260

55

137
320

762

( 0.5" WC Pressure Drop)

87
143
217
506

1205

94

48

82

116
277

661

76
129
183
438

1045

Maximum Capacity for Gas Flex Connectors in Cubic Feet per Hour of Natural Gas

Pipe
Size

1/2"
3/4"

1"

1 1/4"

12" 24" 36" 48" 60" 72"

180 150

290
581

1470

Maximum Capacity for Gas Flex Connectors in Thousands of Btuh Liquified Petroleum

Pipe
Size

1/2"
3/4"

1"

1 1/4"

** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.

12" 24" 36" 48" 60" 72"

288 240

465
930

2352

16

Length in Inches

125
255

512

1200

Length in Inches

200
409
825

1920

106
215
442

1130

169
344
708

1808

(0.60 Specific Gravity, 0.5" WC Pressure Drop)

93
197
397
960

( 0.5" WC Pressure Drop)

149
315
638

1536

86
173
347
930

137
278
556

1488

Installation and service must be performed by a qualified plumber. In the
Commonwealth of Massachusetts, this product must be installed by a licensed

9.

This appliance is suitable for potable water and space heating applications. Do not use this appliance if any part has
been underwater. Immediately call a qualified service technician to inspect the appliance and replace any part of the
control system and gas control which has been under water.

If the water heater is installed in a closed water supply system, such as one having a backflow preventer in the cold
water supply line, means shall be provided to control thermal expansion. Contact the water supplier or a local plumb­ing inspector on how to control this situation.

A pressure relief valve must be installed near the hot water outlet that is rated in accordance with and complying with
either The Standard for Relief Valves and Automatic Shutoff Devices for Hot Water Supply Systems, ANSI Z21.22, or
The ANSI/ASME Boiler and Pressure Vessel Code, Section IV ( Heating Boilers ). This pressure relief valve must
be capable of an hourly Btu rated temperature steam discharge of 180,000 Btuh (140,000 Btuh for NR66-SV (-OD)).
Multiple valves may be used. The pressure relief capacity must not exceed 150 psi. No valve shall be placed between
the relief valve and the water heater. The relief valve must be installed such that the discharge will be conducted to a
suitable place for disposal when relief occurs. No reducing coupling or other restriction may be installed in the dis­charge line. The discharge line must be installed to allow complete drainage of both the valve and the line. If this unit
is installed with a separate storage vessel, the separate vessel must have its own temperature and pressure relief
valve. This valve must also comply with The Standard for Relief Valves and Automatic Gas Shutoff Devices for Hot
Water Supply Systems, ANSI Z21.22. (in the U.S. only). A temperature relief valve is not required, but if one is used,
do not install the valve with the probe directly in the flow of water. This may cause unwarranted discharge of the valve.

Piping and components connected to the water heater shall be suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.
A water heater used to supply potable water may not be connected to any heating system or components previously
used with a nonpotable water heating appliance.
When water is required in one part of the system at a higher temperature than in the rest of the system, means such
as a mixing valve shall be installed to temper the water to reduce the scald hazard.

Water Piping

plumber or gas fitter in accordance with the Massachusetts Plumbing and Fuel
Gas Code 248 CMR Sections 2.00 and 5.00. Observe all applicable codes.

• Flush water through the pipe to clean out metal powder, sand and dirt before connecting it.

• Perform the following insulation measures for prevention of freezing.

• Take appropriate heat insulation measures (e.g., wrapping with heat
insulation materials, using electric heaters) according to the climate of
the region to prevent the pipe from freezing.

• Make sure that there are no water leaks from the cold and hot water
supply pipes, then insulate the pipes completely.

• Be sure to also completely insulate the water supply valve and the
cold and hot water connections on the water heater (refer to the figure
on the right).

• Do not cover the water drain plug with insulation so that water in the
pipe can be drained. (Refer to the figure in the right.)

Use a union coupling or flexible pipe for connecting the pipes to reduce the force applied to the piping.

•

• Do not use piping with a diameter smaller than the coupling.

• When feed water pressure is too high, insert a depressurizing valve, or take water hammer prevention measure.

• Avoid using joints as much as possible to keep the piping simple.

• Avoid piping in which an air holdup can occur.

• If installing the unit on a roof:

• About lower-level hot water supply
If the unit is installed on a roof to supply water to the levels below, make sure that the water pressure supplied to
the unit does not drop below 29 psi. It may be necessary to install a pump system to ensure that the water pressure
is maintained at this level.
Check the pressure before putting the unit into operation.
Failure to supply the proper pressure to the unit may result in noisy operation, shorter lifetime of the unit, and may
cause the unit to shut down frequently.

Completely insulate
the water inlet and
outlet fittings.

Do not cover the water
drain plug with insulation
so that water in the pipe
can be drained.

Insulate the water
supply valve completely.

17

Supply water piping

•

Do not use PVC, iron, or any piping which has been
treated with chromates, boiler seal or other chemicals.

•

Mount a check valve and a shut off valve (near the inlet).

• In order for the client to use the water heater
comfortably, 98.1 to 491 kPa (14 to 70 psi) of
pressure is needed from the water supply.
Be sure to check the water pressure. If the water
pressure is low, the water heater cannot perform
to its full capability, and may become a source of
trouble for the client.

Drain piping

• Expansion water may drop from the pressure
prevention device and wet the floor. If neces­sary, provide drain piping or use a drain hose to
remove the water.

Hot water piping

• Do not use lead, PVC, iron or any piping which

• The longer the piping, the greater the heat loss.

• Use mixing valves with low water resistance. Use

• If necessary, use a pump or other means to en-

has been treated with chromates, boiler seal or
other chemicals.

Try to make the piping as short as possible.

shower heads with low pressure loss.

sure that the supply water pressure to the inlet of
the heater does not fall below 29 psi when the
maximum amount of water is being demanded.
Also install a pressure meter on the inlet. If this is
not done, local boiling will occur inside the water
heater causing abnormal sounds and decreasing
the durability of the heat exchanger.

18

Water Treatment

If this water heater will be installed in an application where the supply water is hard, the water must be
treated with either a water softener, which removes the hardness, or by using sequestering agents, such
as the Noritz Scale Shield, that reduce the amount of scale deposits. Refer to the below tables for sug­gested treatment and maintenance measures to be taken based on the water hardness level. Damage to
the water heater as a result of water in excess of 12 gpg (200 mg/L) of hardness is not covered by the
Noritz America Limited Warranty.

Note: When installing a water softener, consult with the manufacturer for proper sizing and installation

guidelines; the below diagram is for reference only. For more information about Scale Shield, contact
Noritz America at 866-766-7489.

Residential Use Treatment Guidelines Commercial Use Treatment Guidelines

Hardness

Type of Water

Soft

Slightly Hard

Moderately

Hard

Hard

Very Hard

Extremely

Hard

* Install Noritz Isolation Valves to allow for flushing.

Level

0-1 gpg

(0-17 mg/L)

1-3 gpg

(17-51 mg/L)

3-7 gpg

(51-120 mg/L)

7-10 gpg

(120-171 mg/L)

10-14 gpg

(171-239 mg/L)

> 14 gpg

(> 239 mg/L)

Treatment

Device

None None

None None

ScaleShield Once a Year Once a Year

ScaleShield

Water

Softener

Water

Softener

Flush

Frequency*

Once a Year

Softener

Required

Softener

Required

Hardness

Type of Water

Soft

Slightly Hard

Moderately

Hard

Hard

Very Hard

Extremely

Hard

*Install Noritz Isolation Valves to allow for flushing.

**Flushing is required if a water softener is not installed.

Level

0-1 gpg

(0-17 mg/L)

1-3 gpg

(17-51 mg/L)

3-7 gpg

(51-120 mg/L)

7-10 gpg

(120-171 mg/L)

10-14 gpg

(171-239 mg/L)

> 14 gpg

(> 239 mg/L)

Treatment

Device

None

None

Water

Softener

Suggested

Water

Softener

Suggested

Water

Softener

Water

Softener

Flush

Frequency*

None

None

Twice a

Softener

Required

Softener

Required

Year

**

**

Pressure

Relief

Valve

Drain

NORITZ
Tankless

Gas Water

Heater

Shutoff Valve

Hot Water to Fixtures

Water Treatment System

Cold to Water

Heater

Optional Sediment

Filter

Water Treatment Device

Shutoff Valve

City Water Supply

19

10. Plumbing Applications

Recirculation System

Hot Water Return

Isolation
Kit(*3)

NORITZ
Tankless Gas
Water Heater

Cold Water Supply

Fixtures

Expansion Tank
(Install according
to local code)

Gas Supply

Notes:

1. Size the pump to provide a maximum of 5.7 L/min.
(1.5 GPM) through the system at 3m (10 ft) of
head plus piping losses.
Adjust the flow using a globe valve and verify the
flow rate with the maintenance monitors.

2. Set the Aquastat to 5°C (10°F) below the set
output temperature.

3. Noritz recommends the use of an Isolation Kit
with the installation.
These kits include an integrated shut-off and serv­ ice valve with unions and a pressure relief valve.

105

Pump

Isolation
Kit(*1)

Aquastat(*2)

Optional 30-38L (8-10 Gallon)
Storage Tank
(To alleviate cold water sandwich)

Hot Water

Globe
Valve

Pump(*1)

120VAC

Neutral
Ground
Live

Aquastat Wiring

Use Honeywell Aquastat

(Model L6006A or L6006C)

Combination Potable Water and Space Heating System

Notes:

1. Noritz recommends the use of an Isolation Kit with
the installation.
These kits include an integrated shut-off and serv­ ice valve with unions and a pressure relief valve.

NORITZ
Tankless Gas
Water Heater

Pump(*2)

Gas Supply

Check
Valve(*3)

Air Handler

Flow Switch(*4)

2. Size the pump to provide a maximum of
(2 GPM.)
through the water heater and Air Handler.

3. Check valve required if it is not included with the
pump.

4.
the domestic hot water flow reaches 7.5 L/min. (2 GPM.)
Adjust as necessary to prevent cycling.

5. If the system requires water for space heating at
a higher temperature than for other uses, means
such as a mixing valve shall be provided to temper
the water for the other uses to help prevent scald

-ing.

6. Expansion tank required if a backflow preventer is
installed.

Optional
Expansion Tank(*6)

with a head pressure equal to the loss

Set the flow switch to deactivate the Air Handler when

Backflow Preventer
(optional)

Cold Water
Supply

R

B

S

W

7.5 L/min.

20

Hot Water

Mixing Valve(*5)

Fixtures