Noritz NC250-DV-ASME Installation Manual

NORITZ AMERICA

*SBA8379*

Installation Manual

CORPORATION

TANKLESS GAS WATER HEATER

NC250-DV-ASME (Indoor 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

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

WARNING

CAUTION

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

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

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

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.

SBA8379-2

Rev. 03/13

CERTIFIED

R

Complies with

jurisdictions having

40 ng/J or 55 ppm

NOx regulations

(Natural Gas Only)

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).

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

1.

Included Accessories

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

Part Shape Q’ty

Anchoring Screw

Remote Controller

(See p. 20)

Heat Exchanger

Inspection report

2.

Optional Accessories

Flue Terminal

VT4-TL

Flue Terminal

VT4-TS

5

1

1

1

1

Owner's Guide, Warranty,

Installation Manual

(this document)

Remote Controller

Cord (10ft)

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

Quick Connect

Cord

Remote Controller

Cord (26 ft)

Q’tyShapePart

1

each

1

Q’tyShapePartPart Shape Q’ty

1

1

System Controller

Isolation Valves

(includes pressure

2

relief valve)

1

Pipe Cover

(PC-3S-SUS)

1

1

3.

Quick Connect Multi System Installation

• The Quick Connect Multi System allows the installation of two units together utilizing only the Quick
Connect Cord.

The Quick Connect Cord is 6 ft. long. Install the units 6-19" apart from each other to ensure the
cord will be able to reach between the units. (See Typical Plumbing diagram).
(If the distance between the two units is too great, not only will the cord not be able to reach,
but the water temperature may also become unstable because of the difference in pipe length
between the two units).

System Diagram

Quick Connect
Cord

Cord
Connector

Typical Plumbing

Cord
Connector

Terminal Block

Remote Controller

Remote Controller Cord

G

Distance at center: 24.3-37.3".

Distance on sides

6-19".

* When connecting two units, use only a

single remote controller.

Note: Connect the remote

controller to only one
of the units.

Gas Supply Piping

Cold Water Supply

Hot Water

Union

Union

Gas Valve

Shutoff Valve

Shutoff
Valve

Hot Water
Cold Water

Size the piping to allow for the maximum
flow rates of the units.

Make this distance as short as possible.
* The hot water temperature will
become unstable as the pipe
length increases.

Union

Quick Connect
Cord

Pressure
Relief
Valve

Shutoff
Valve

Leave enough clearance around the plumbing
to apply insulation. It will be necessary to add
bends to the piping to ensure that this
clearance is available.

• Insulate the hot water piping to prevent heat loss. Insulate and apply heating materials to the cold
water supply piping to prevent heat loss and freezing of pipes when exposed to excessively cold
temperatures.

3

Before Installation

4.

DANGER

Checkup

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

WARNING

Precautions on Vent Pipe Replacement

• The vent system will almost certainly need to be replaced when this appliance is being installed.
Use vent pipe that is listed to UL 1738 for Category III appliances for the exhaust venting. Category
III listed vent pipe is suggested for the air supply pipe also, but other materials may be acceptable.
Consult local codes.
* If Category III listed vent pipe is already installed, check for punctures, cracks or blockages and

consult with the vent pipe manufacturer before reusing.

Use Approved Vent Materials

• Use only vent materials that are listed to UL 1738 for Category III appliances for the exhaust venting
of this appliance.
Improper venting may result in fires, property damage or exposure to Carbon Monoxide.

Snow Precaution

• If this product will be installed in an area where snow is known to accumulate, protect the vent
termination from blockage by snow drifts or damage from snow falling off of roofs.

Check the Gas

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

• Check that the gas supply line is sized for
250,000 Btuh for this unit.

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. Do not use a solar pre-heater with the quick-connect multi-system.

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.

4

Choosing Installation Site

5.

* 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

• Locate the 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.

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.

• 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.

Prohibited

• 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.

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

CAUTION

• The water heater is designed for indoor installation only. Never install it
outdoors or in a bathroom, it may be damaged or a fire may be caused.

• Consult with the customer concerning the location of installation.

• Install the water heater in an area that allows for the proper clearances
to combustible and noncombustible construction. Consult the rating
plate on the appliance for proper clearances.

• Do not install the water heater in a place where it may be threatened by
falling objects, such as under shelves.

• The water heater must be installed in a place where supply and exhaust
pipes can be installed as directed.

• 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.

Prohibited

5

CAUTION

• Avoid installation above gas ranges or stoves.

• 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.

• Before installing, make sure that the exhaust flue termination will
have the proper clearances according to the National Fuel Gas
Code (ANSI Z223.1).

Prohibited

Be sure to do

Prohibited

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: 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

6

6. 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.

Item

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

Distance from combustibles

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

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

• If possible, leave 3" or more above and
below the vent pipe to facilitate inspec-

repair/inspection

tion and repair if necessary

Securing of space for

Check Illustration

6" or
more

Distance from
the side

8" or
more

8" or
more

24" or
more

12"
or
more

4" or
more

3"
3"

or more

or more

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.

D

E

L

B

DescriptionRef

Clearance above grade, veranda, porch,

A=

deck, or balcony
Clearance to window or door that may

B=

be opened

C=

Clearance to permanently closed window
Vertical clearance to ventilated soffit

located above the terminal within a

D=

horizontal distance of 2 feet (61 cm)
from the center line of the terminal

E=

Clearance to unventilated soffit
Clearance to outside corner

F=
G=

Clearance to inside corner
Clearance to each side of center line

H=

extended above meter/regulator assembly

I=

Clearance to service regulator vent outlet
Clearance to nonmechanical air supply

J=

inlet to building or the combustion air inlet
to any other appliance

Clearance to a mechanical air supply inlet

K=

Clearance above paved sidewalk or paved

L=

driveway located on public property
Clearance under veranda, porch, deck,

M=

or balcony

1

In accordance with the current CSA B149.1 Natural Gas and Propane Installation Code

2

In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code

† 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.
* Clearance in accordance with local installation codes and the requirements of the gas supplier.

Clearance to opposite wall is 24 inches (60 cm).

C

F

B

G

A

B

B

B

B

J

A

Vent Terminal

Air Supply Inlet

Canadian Direct Vent

Installations

12 in (30 cm)

36 in (91 cm)

3 ft (91 cm) within a height
15 ft (4.5 m) above the
meter/regulator assembly

3 ft (91 cm)

36 in (91 cm)

6 ft (1.83 m)

7 ft (2.13 m)†

12 in (30 cm)‡

1

*

*

*
*
*

H

I

M

K

Area Where Terminal
is Not Permitted

US Direct Vent

Installations

12 in (30 cm)

12 in (30 cm)

12 in (30 cm)

3 ft (91 cm) above if within

10 ft (3 m) horizontally

2

*

*

*
*
*

*
*

*

*

7. Installation

Securing to the wall

8

Be sure to do

HIGH ELEVATION

DISCONNECT

• 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 damaged and may become highly dangerous.

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

Item

CAUTION

• 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.

IllustrationCheck

Location of Screw Hole

Mounting Bracket
(upper)

Locating Screw Holes

Anchoring 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
2,000 ft. (610m) 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 "73" code displayed on the remote controller

Above 2,000 ft.

and a cease in operation. If this occurs, disconnect,
then reconnect power to the water heater to reset the
system.

Installations at Elevations

Vent Pipe Installation

8.

(Indoor Installation Only)

Vent Terminal Installation

• Follow the installation instructions included with the vent terminal. It is suggested that the appliance be
vented horizontally through a sidewall. If a vertical vent termination is required, it must follow the
requirements of this section (p.9-12).

9

Vent Terminal Installation Precautions

Note the following vent terminal installation requirements

• Do not install the vent terminal indoors • Install the vent terminal with a downward slope

downward

• Install with the proper length protruding through the wall

Proper installation. The
red line can be seen,but
the red rectangle cannot
be seen from the outside.

Avoid installing the terminal where obstacles will block it

•

Vent terminal

Snow
drift

• Do not cover the vent terminal with any type of
protective screen or enclosure. Blocked terminals
can cause abnormal combustion resulting in
undesired performance from the water heater.

not far
enough

Vent terminal

Tree

too far

upward

slope

Avoid storing hazardous

•
objects near the terminal

Gasoline

• Clearance from vent terminal.
If multiple units are installed,

terminals must be separated
by a minimum of either 12"
horizontally or 60" vertically.

12" or more

Vent terminal

Vent terminal

slope

Gas

60" or
more

Vent terminal models

• Use only the following models of Noritz
vent terminals with this unit.

VT4-TL

•
VT4-TS

•

Vent terminal

•

Vent terminal size variations are listed in the table below.
Choose the model according to the wall thickness required.

Model
VT4-TL-5 3.5" to 5.1"
VT4-TL-8 5.1" to 8.3"

VT4-TL-14 8.3" to 14.6"
VT4-TL-27 14.6" to 27.2"

(for long vent runs)
(to be installed directly

on top of the appliance)

Wall thickness (in.)

Intake pipe

10

Vent system installation example

Elbows

Straight pipe

sloping down

Exhaust
pipe

Elbow

Main unit

Use a listed Category III vent adapter
to connect the flue collar to the vent
system. Use Category III vent pipe
for the entire length of the exhaust
pipe.

Vent terminal