Noritz NC1991-DVC User manual

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.
Prohibited Disconnect
Power Ground Be sure to do
WARNING: If the information in this manual is not followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
NORITZ AMERICA
CORPORATION
Installation Manual
TANKLESS GAS WATER HEATER
NC1991-DVC (Indoor Installation)
DANGER indicates an imminently hazardous situation which,
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 indicates a potentially hazardous situation which,
if not avoided, may result in minor or moderate injury.
DANGER
WARNING
CAUTION
Requests to Installers
• In order to use the water heater safely, read this installation manual carefully, and follow the in-
stallation 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.
CAUTION
SBA8873-1
Rev. 04/12
FOR USE IN RESIDENTIAL 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.
Noritz America reserves the right to discontinue, or change at any
time, the designs and/or specifications of its products without notice.
Low NOx
Approved by
SCAQMD
14 ng/J or 20 ppm
(Natural Gas Only)
CERTIFIED
R
*SBA8873*

2
1.
Included Accessories
The following accessories are included with the unit.
Check for any missing items before starting installation.
Q’ty
ShapePart
Tapping Screw 1
each
Part Shape Q’ty
5
2.
Optional Accessories
The accessories listed below are not
included with the units, but may be necessary
for installation.
Q’ty
ShapePartPart Shape Q’ty
QuickConnect Cord
(QC-2) 1
1
IsolationValves
(includes pressure
reliefvalve)
Owner's Guide, Warranty,
Installation Manual
(this document)
Part No. Description
4"-CVP-4STR
12"-CVP-12STR
24"-CVP-24STR
36"-CVP-36STR
Adjustable
Part No. Description
CVT-S
Flange
Adapter
Horizontal Termination
FlangeElbow
Part No. Description
CRCAI-1
90 Elbow
Adjustable
90 Elbow
Support Strap
CVP-45ELB
CSCR-1
Standard Horizontal Kit
FP-5-OUT
RoofFlashing
(0-45 )
Straight Straight
Termination
11"-CVP-11ADJ
16"-CVP-16ADJ
40"-CVP-40ADJ
Rain Cap with Air Intake
CWF
StormCollarRing
CVP-90ELB SS5-2
CARF-1
45 Elbow Plate
CVP-90ADJELB
CWF-90ELB Horizontal Kit - CVK-H
Vertical Kit - CVK-V
Note: Additional vent pieces are available; consult the latest product catalogue for details.
Remote Controller
(See p.21) 1
1
System Controller
(SC-301-6M-EXT)
Drain hose
(With clamp) 1

3
G
Quick Connect
Cord
Gas Supply Piping
Cold Water Supply
Hot Water
Remote Controller
*1
Cord
Connector Cord Connector
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' (2m) long. Install the units 2-18" (50-457mm) 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).
*1 When connecting two units, disconnect
the remote controller connector from
the other unit.
Note: Connect the remote
controller to only one
of the units.
System Diagram
• 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 exces-
sively cold temperatures.
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.
Size the piping to allow for the
maximum flow rates of the units.
Distance at center: 16-32" (406-812mm).
Union
Hot Water
Shutoff
Valve
Cold Water
Distance on sides
2-18" (50-457mm).
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
Union
Gas
Valve
Shutoff Valve
The backflow preventer is
put up before it diverges.
Typical Plumbing

4
4. Before Installation
Checkup
• Check the fixing brackets and vent pipe yearly for damage or wear. Replace if necessary.
DANGER
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
mayoccur 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.
WARNING
CAUTION
Check the Gas
• Check that the rating plate indicates the
correct type of gas.
• Check that the gas supply line is sized for
199,900Btuh 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.
Precautions on Vent Pipe
• This appliance requires the use of special concentric type vent pipe specified by Noritz America.
Do not attempt to use materials that are not specified for use on this appliance.
Improper venting may result in a fire, 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 termi-
nationfrom blockage by snowdriftsor damage from snowfalling offofroofs.

5
5. Choosing Installation Site
* 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.
• 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.
• 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.
• 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
recreational vehicle or on a boat.
• 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.
Theheat and moisture fromthe water heater maycausediscoloration of
wallsand resinous materials, orcorrosion of aluminum materials.
Prohibited
DANGER
WARNING
CAUTION
Prohibited

6
• 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).
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 re-
quest instructions.
Be sure to do
Prohibited
Prohibited
CAUTION
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

7
6. Installation Clearances
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.
WARNING
Item
Distance from combustibles
• Maintain the following clearances
from both combustible and
non-combustible materials.
• There must be a clearance of 24" (600mm)
or more in front of the Flue terminal.
• This restriction will not be applied to an
area where an effective shield makes a
clearance of 24" (600mm) or more in
front of the exhaust outlet.
Check Illustration
• If possible, leave 8" (200mm) or more on
either side of the unit to facilitate inspection.
• If possible, leave 24" (600mm) or more
in front of the unit to facilitate maintenance
and service if necessary.
• If possible, leave 3" (75mm) or more
above and below the vent pipe to facilitate
inspection and repair if necessary.
Securing of space for
repair/inspection
24" (600mm)
or more
8" (200mm)
or more
Outdoor Clearances to Opening
into Any Building
Distance from
the side
12" (300mm)
or more
2" (50mm)
or more
12" (300mm)
or more 12" (300mm)
or more
12" (300mm)
or more
There must be no
building opening
within this area. 12" (300mm)
or more
Flue terminal
3" (75mm) or more
3" (75mm) or more
4" (100mm)
or more
8" (200mm)
or more

8
7. Installation
Securing to the wall
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.
Clearance
A= Above grade, veranda, porch, deck,
or balcony
B= Window or door that may be opened
C= Permanently closed window
D=
Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 2' (0.6m) from
the center of the terminal *
E= Unventilated soffit *
F= Outside corner *
G= Inside corner *
H= Each side of center line extended
above meter/regulator assembly 3' (0.9m) within a height 15' (4.5m)
above meter/regulator assembly
I= Service regulator vent outlet 3' (0.9m)
J= Nonmechanical air supply inlet or
combustion air inlet to any other
appliance
12" [36" (900mm)]
K= Mechanical air supply inlet 3' above if within 10' [6'(1.8m)]
L= Above paved sidewalk or paved
driveway located on public property
Under veranda, porch, deck, or
balcony
* [7' (2.1m ***)]
M=
[ ] = 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.
* [12" (300mm)****]
*
12" [12" (300mm)]
12" [36" (900mm)]
Area Where Terminal
is Not Permitted
Vent Terminal
Air Supply Inlet

9
IllustrationCheck
6. Drill holes for the remaining four screws.
7. Hang the unit again by the first screw, and then
insert and tighten the remaining four screws.
8. Take waterproofing measures so that water does
not enter the building from screws mounting the
device.
• Make sure the unit is installed securely so that it will
not fall or move due to vibrations or earthquakes.
• The distance between the unit and the wall can be
adjusted within the range of 0.4 - 1.8" (10 - 46mm).
Adjust the brackets as necessary to accommodate
the vent system (factory default is 0.4" (10mm)).
1. Loosen the four screws in the mounting bracket (upper),
match the desired mark to the back of the unit, and
then tighten the screws.
2. Loosen the four screws in the mounting bracket (lower) and
secure it in the same position as the upper mounting bracket.
3. Drill a single screw hole, making sure to hit a stud.
4. Insert and tighten the screw and hang the unit by
the upper wall mounting bracket.
5. Determine the positions for the remaining four screws
(two for the top bracket and two for the bottom), and
remove the unit.
• The weight of the device will be applied to the wall. If the strength of the wall is not suffi-
cient, 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.
Locating Screw Holes
Mounting
Structure
• 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.
Item
CAUTION
Be sure to do
Mounting Bracket
(upper)
Tapping Screw
Location of Screw Hole
Locating Screw Holes
Installations at Elevations
Above 2,000 ft.(610m).
• Adjust the dip switches as illustrated in the table to
the right if this water heater is installed at an altitude
of 2000 ft. (610m) or higher.
• Disconnect power to the water heater before
changing the dip switches. Failure to perform this
step will result in a "73" code displayed on the remote
controller and a cease in operation. If this occurs,
disconnect, then reconnect power to the water heater
to reset the system.
Note : Please refer to page 21 for the location of the
dip switch bank.
0.4 - 1.8"
(10 - 46mm)
mounting bracket
(upper)
mounting bracket
(lower)
mark
(0.4" (10mm) intervals)
* Do not change an other dipswitches.
* igh elevation ad ustment.
5
2 001 - 4 000 ft ( 11 - 1 220m)
0 - 2 000 ft (0 - 10m)
4 001 - 000 ft (1 221 - 1 8 0m)
001 - 8 000 ft (1 8 1 - 2 440m)

10
> 3" (75mm)
(20-75mm)
0.8"-3"
< 0.8"
(20mm)
Straight Termination Installation Precautions.
Note the following vent terminal installation requirements.
• Do not install the vent terminal indoors
• Install the vent terminal with a downward slope
upward
slope
downward
slope
•Install with the proper length protruding through the wall •Avoid storing hazardous
objects near the terminal
Gasoline
Gas
Proper installation.
The red line can be
seen, but not more
than 2.2" (55mm)
from the wall.
Vent terminal
Vent terminal
not far
enough too far
Snow
drift Tree
•Avoid installing the terminal where obstacles
will block it
•
Do not cover the vent terminal with any type of protective
screen or enclosure. Blocked terminals can cause abnor-
mal combustion resulting in undesired performance from
the water heater.
8. Vent Pipe Installation
• This appliance requires the use of special concentric type vent pipe specified by Noritz America.
Do not attempt to use materials that are not specified for use on this appliance.
WARNING
Be sure to do
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.
• Clearance from vent terminal.
If multiple units are installed, the concentric vent terminals must be separated
by a minimum of either 12" (300mm) horizontally or 60" (1.5m) vertically.
Vent terminal Vent terminal
12" (300mm) or more
60" (1.5m) or more

1
1
The power must be unplugged when
adjusting the dip switches to switch
the airflow amount.
The unit can be adjusted to accommodate longer vent runs; refer to the below table to find the
maximum vent length based on the number of elbows. Adjust the dip switches according to the vent
condition noted in the tables below.
Note: By default, the unit has been set to the "minimum length" condition. When adjusting the dip
switches for longer vent runs, the BTUH input of the appliance will be reduced by up to 8%.
Maximum Vent Length Adjustment Dip Switches
- ne 0 elbow ma imum length ft (0. m)
(with dip switches set at "minimum length" condition)
- Two 0 elbows ma imum length 0 ft ( .0m)
(with dip switches set at "maximum length" condition)
[Maximum Vent Length Example]
• Disconnect power to the water heater before changing the dip switches. Failure to perform
this step will result in a "73" code displayed on the operation panel and a cease in operation . f
this occurs, disconnect, then reconnect power to the water heater to reset the system.
Note : Please refer to page 21 for the location of the dip switch bank.
3
6
9
12
15
18
21
24
27
30
32
35
38
41
0.90
1.80
2.70
3.60
4.50
5.40
6.30
7.20
8.10
9.00
9.90
10.80
11.70
12.60
m1023456ft Vent length Elbows
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Number of
pieces** 11
1
12
2
23
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
44
4
4
3
3
3
32
2
** ble ssumes str ight ent pieces re 3 0.9m e ch.
horter or longer ent pieces m lso be use up to the m imum llowe ent length.
2
2
2
1 inimum length
2
3
4
hort length
ong length
imum length
<Maximum Vent Length Configurations>
* o not ch nge n other ipswitches.
* Vent length con ition.
1 inimum length
78
N
2 hort length
3 ong length
4 imum length

12
Horizontal Vent Termination • Terminate at least 12" (300mm) above
grade or above snow line.
• Terminate at least 7' (2.1m) above a public
walkway, 6' (1.8m) from the combustion air
intake of any appliance, and 3' (0.9m) from
any other building opening, gas utility me-
ter, service regulator etc.
• T
erminate at least 3' (0.9m) above any forced
air inlet within 10' (3m), 1' (0.3m) below,
1' (0.3m) horizontally from or 1' (0.3m)
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" (6mm)
downwards for every 12" (300mm) towards
the termination.
•
The integrated condensate collector must be
used for vertical runs in excess of 3' (0.9m).
Remove the cap from the collector prior to at-
taching the drain line.
• In the Commonwealth of Massachusetts a car-
bon monoxide detector is required for all side
wall horizontally vented gas fuel equipment.
Please refer to Technical Bulletin TB 010606
for full installation instructions.
lbow
anger
Straps
lange
dapter
Plate
Termination
* (0. m) Ma .
Slope vent
Downwards
* Condensate collector
must be used if the
vertical run e ceeds
(0. m).
Drain condensate
according to
local codes.
• Connect the vent pipe firmly so that it will pre-
vent exhaust gases from leaking.
• Steam or condensed water may drip out of the
vent terminal. Dispose of this condensed water
according to local codes and in order to prevent
injury or property damage.
• 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.
• Support the vent pipe with hangers at a mini-
mum of every 7' (2.1m).
• Make the vertical pipe as short as possible.
• Do not common vent or connect more than
one appliance to this venting system.
•
Terminate at least 12" (300mm) above grade or
snow line.
• Terminate at least 7' (2.1m) above a public
walkway.
• Exceeding the maximum vent length is danger-
ous and may result in bad combustion.
•
Install the vent terminal so that all exhaust is di-
rected to and all intake air is taken from outdoors.
• Do not store hazardous or flammable substanc-
es near the vent terminal.
•
Slope the vent pipe 1/4" (6mm) for every 12"
(300mm) either towards the horizontal termination
or towards the integrated condensate collector.
When using the condensate collector, create a
trap in the drain line and pre-charge it with wa-
ter to prevent exhaust gas leakage.
• Maintain the same vent pipe diameter all the
way to the end.
• Noritz Concentric vent pipe is approved for use
on this appliance with zero clearance to com-
bustibles.
• Use only Noritz specified venting products.
WARNING
Be sure to do
CARBON MONOXIDE POISONING
Do not remove the cap from the condensate collector unless it is being used to drain
condensate. Without the cap in place, flue products could enter the living space.

13
(Combustible material)
External wall,
combustible material
• Inspection openings are suggested for the vent intake and exhaust
pipes if they are installed in an enclosure. These openings should
be near the entrance and exit of the vent into the enclosure.
• These openings should be 18" x 18" (450mm x 450mm).
Suggested inspection openings
18" x 18" (450mm x 450mm)
When the vent pipe passes through an enclosed space:
Ceiling
Sloping down toward vent terminal
Vertical Vent Termination
irestop
irestop
Support
Roof lashing
( ase and dapter)
ir ntake
Pipe
Rain
Cap
5 (1.5m) or more
anger
Strap
lbow
Slope vent
Upwards
* Condensate collector
must be used if the
vertical run e ceeds (0. m).
Drain condensate
according to
local codes.
• Terminate at least 6' (1.8m) from the combus-
tion air intake of any appliance, and 3' (0.9m)
from any other building opening, gas utility me-
ter, 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
8' (2.4m) from a vertical wall or similar obstruc-
tion, terminate above the roof at least 2' (0.6m),
but not more than 6' (1.8m), in accordance
with the National Fuel Gas Code ANSI Z223.1/
NFPA 54.
• Provide vertical support every 7' (2.1m).
• Slope the horizontal vent 1/4" for every
12" (300mm) towards the drain tee.
• The integrated condensate collector must be
used for vertical runs in excess of 3' (0.9m).
Remove the cap prior to attaching the drain
tubing.
• When 2 units are installed in a Quick Connect
Multi System, maintain a minimum distance of
5' (1.5m) between the vertical terminations.

14
Gas Meter
Select a gas meter capable of suppl ing the entire
btuh demand of all gas appliances in the building.
Gas Connection
Do not use piping with a diameter smaller than
the inlet diameter of the water heater.
Gas fle lines are not recommended unless
the are rated for 1 00 btuh.
nstall a gas shutoff valve on the suppl line.
Use onl approved gas piping materials.
ollow the instructions from the gas supplier.
Gas Pressure
Si e the gas line according to total btuh demand
of the building and length from the meter or
regulator so that the following suppl pressures
are available even at ma imum demand
atural Gas Suppl Pressure
Min. 4" WC
Ma . 10.5" WC
P Gas Suppl Pressure
Min. 8" WC
Ma . 14" WC
.Gas Piping
The appliance and its individual shutoff valve must be disconnected from the gas suppl piping s stem
during an pressure testing of that s stem at test pressures in e cess of 1⁄2psig ( .5 kPa).
The ppliance must be isolated from the gas suppl piping s stem b closing its individual manual
shutoff valve during an pressure testing of the gas suppl piping s stem at test pressures e ual to or
less than 1⁄2psig ( .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.
n order to choose the proper si e for the gas line consult local codes or the ational uel Gas Code
S 22 .1.
atural Gas
Meter **See ne t page for the pipe capacit charts.
orit Tankless Gas Water eater
(1 00 tuh)
Clothes Dr er
( 5 000 tuh)
arbecue
(50 000 tuh)
Gas Range Stove
( 5 000 tuh)
10 ( m)
10 ( m)
10 ( m)
10 ( m)
5 (1.5m)
5 (1.5m)
5 (1.5m)
5 (1.5m)
Gas ireplace
(25 000 tuh)
Instructions
1. Si e each outlet branch starting from the furthest
using the tuh re uired and the length from the
meter.
2. Si e each section of the main line using the
length to the furthest outlet and the tuh
re uired b ever thing after that section.
Sample Gas Line
Sample Calculation
utlet 45 (1 .5m) (Use 50 (15m)) 50 000 tuh re uires 1 2"
utlet 40 (12m) 5 000 tuh re uires 1 2"
Section 1 45 (1 .5m) (Use 50 (15m)) 115 000 tuh re uires 4"
utlet C 0 ( m) 5 000 tuh re uires 1 2"
Section 2 45 (1 .5m) (Use 50 (15m)) 150 000 tuh re uires 4"
utlet D 25 (7.5m) (Use 0 ( m)) 25 000 tuh re uires 1 2"
Section 45 (1 .5m) (Use 50 (15m)) 175 000 tuh re uires 1"
utlet 25 (7.5m) (Use 0 ( m)) 1 00 tuh re uires 4"
Section 4 45 (1 .5m) (Use 50 (15m)) 74 00 tuh re uires 1-1 4"
Section Section 2 Section 1
utlet
utlet
utlet C
utlet D
utlet
5 (1.5m)5 (1.5m)
Section 4
Measuring Gas Pressure
n order to check the gas suppl pressure to the unit a
tap is provided on the gas inlet. Remove the he head
philips screw from the tap and connect a manometer
using a silicon tube.
n 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 b removing the he
head philips screw and connecting a manometer with a
silicon tube or b removing the 1 8" PT screw with an
allen wrench and connecting the appropriate pressure
gauge.

15
Ma imum atural Gas Deliver Capacit in Cubic eet per our (0. 0 Specific Gravit 0.5" WC Pressure Drop)
Contact the Gas Supplier for tu Cubic t. of the Supplied Gas. 1000 TU Cubic t. is a T pical Value
Ma imum i uefied Petroleum (Undiluted) Deliver Capacit in Thousands of tuh (0.5" WC Pressure Drop)
ength in eet
ength in eet
Pipe
Si e
Pipe
Si e
12"
12"
4"
4"
1"
1"
1 1 4"
1 1 4"
1 1 2"
1 1 2"
2"
2"
2 1 2"
"
12"
4"
10(m)20(m) 0(m)
40 (12m) 50 (15m) 0 (18m) 70 (21m) 80 (24m) 0 (27m) 100 ( 0m) 125 ( 7.5m)
10(m)20(m) 0 ( m) 40 (12m) 50 (15m) 0 (18m) 70 (21m) 80 (24m) 0 (27m) 100 ( 0m) 150 (45m) 200 ( 0m)
10(m) 20(m) 0 ( m) 40 (12m) 50 (15m) 0 (18m) 70 (21m) 80 (24m) 0 (27m) 100 ( 0m) 150 (45m) 200 ( 0m)
10(m) 20(m) 0 ( m) 40 (12m) 50 (15m) 0 (18m) 70 (21m) 80 (24m) 0 (27m) 100 ( 0m) 150 (45m) 200 ( 0m)
125 ( 7.5m)
174
84
1404
210
4050
455
11 412
170
2 277
11
24
470
5
1445
2784
44 7
784
11 484
15 8
200
77
775
11 1
22 5
5
2
222
12 847
dapted from UPC 1 7
82
171
2
11
04
51
78
10 5
7
152
28
588
880
1
270
4778
5
745
18
25
52
78
15
244
42
8
88 0
1
127
2
40
74
141
225
8
58 1
812
5 5 50 44
118 111 104
222 208 1 7 174
45
8
115
20
705
5425
7557
428
41
12 4
147
50 0
70 1
404
05
11 5
1857
284
4808
8
58
5
10
14
210
42 1
5
275
57
1071
2205
07
221
18
72
14
22
41
152
15
50
1212
1858
45
12
27
504
10
155
22
114
27
448
1
1417
24
10
217
40
84
1275
24
178
771
1181
2205
8
185
4
724
108
2047
8
17
22
77
102
121
78
12
07
0
7
1811
14
275
57
8
10
12
252
511
787
14
55
112
21
440
75
12 0
Ma imum Capacit of le TracPipe in Cubic eet per our of Natural Gas (0. 0 Specific Gravit 0.5" WC Pressure Drop)
ength in eet
Pipe
Si e
4"
1"
1 1 4"
1 1 2"
2"
20
8
14
12 1
24
147
2
418
888
2078
121
218
4
72
18
105
188
284
25
1472
4
18
251
55
117
8
15
227
50
120
80
141
20
471
1114
75
12
14
440
1042
71
125
181
415
8
7
118
171
55
4
17
20
72
48
82
11
277
1
R
Ma imum Capacit of le TracPipe in Thousands of tuh Liquefied Petroleum ( 0.5" WC Pressure Drop)
ength in eet
Pipe
Si e
4"
1"
1 1 4"
1 1 2"
2"
25
05
71
1
48
22
425
1
1404
285
11
44
528
114
284
1
27
44
88
227
14
25
7
884
2082
1
241
5
805
102
12
222
0
745
17 1
118
208
07
147
112
17
28
5
1554
10
18
270
21
1475
87
14
217
50
1205
7
12
18
48
1045
R
** or reference onl . Please consult gas pipe manufacturer for actual pipe capacities.
** or reference onl . Please consult gas pipe manufacturer for actual pipe capacities.
Ma imum Capacit for Gas le Connectors in Cubic eet per our of Natural Gas (0. 0 Specific Gravit 0.5" WC Pressure Drop)
ength in nches
Pipe
Si e
12"
4"
1"
1 1 4"
12" ( 00mm) 24" ( 00mm) " ( 00mm) 48" (1200mm) 0" (1500mm) 72" (1800mm)
12" ( 00mm) 24" ( 00mm) " ( 00mm) 48" (1200mm) 0" (1500mm) 72" (1800mm)
180 150
20
581
1470
125
255
512
1200
10
215
442
11 0
17
7
0
8
17
47
0
ength in nches
Pipe
Si e
12"
4"
1"
1 1 4"
288 240
45
0
252
200
40
825
120
144
708
1808
14
15
8
15
17
278
55
1488
Ma imum Capacit for Gas le Connectors in Thousands of tuh Liquefied Petroleum ( 0.5" WC Pressure Drop)
** or reference onl . Please consult gas pipe manufacturer for actual pipe capacities.
TracPipe is a registered trademark of mega le .
Gas ine Si ing for a orit Tankless Gas Water eater

1
1.
Water Piping
This appliance is suitable for combination potable water and space heating applications. t cannot be used for space
heating applications only. Do not use this appliance if any part has been underwater. Immediately call a qualified
service technician to inspect the appliance and replace an part of the control s stem 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 suppl line means shall be provided to control thermal e pansion. Contact the water supplier or a local
plumbing inspector on how to control this situation.
pressure relief valve must be installed near the hot water outlet that is rated in accordance with and compl ing
with either The Standard for Relief Valves and utomatic Shutoff Devices for ot Water Suppl S stems S
21.22 or The S SM oiler and Pressure Vessel Code Section V ( eating oilers). This pressure relief
valve must be capable of an hourl tu rated temperature steam discharge of 1 00 tuh. Multiple valves ma be
used. The pressure relief capacit must not e ceed 150 psig. o 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. o reducing coupling or other restriction ma be installed in the discharge line. The
discharge line must be installed to allow complete drainage of both the valve and the line. f 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 compl with The Standard for Relief Valves and utomatic Gas Shutoff Devices for ot Water Suppl
S stems S 21.22. (in the U.S. onl ). temperature relief valve is not re uired 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.
To ic chemicals such as those used for boiler treatment shall not be introduced into the potable water.
water heater used to suppl potable water ma not be connected to an heating s stem or components
previousl used with a nonpotable water heating appliance.
When water is re uired in one part of the s stem at a higher temperature than in the rest of the s stem means
such as a mi ing valve shall be installed to temper the water to reduce the scald ha ard.
Installation and service must be performed by a qualified plumber. In the
Commonwealth of Massachusetts this product must be installed b a licensed
plumber or gas fitter in accordance with the Massachusetts Plumbing and Fuel
Gas Code 248 CMR Sections 2.00 and 5.00. bserve all applicable codes.
lush water through the pipe to clean out metal powder sand and dirt before connecting it.
Perform the following insulation measures for prevention of free ing.
- 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 free ing.
- Make sure that there are no water leaks from the cold and hot water
suppl pipes then insulate the pipes completel .
- e sure to also completel insulate the water suppl valve and the
cold and hot water connections on the water heater (refer to the fig-
ure 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 depressuri ing valve or take water hammer prevention measure.
• Avoid using joints as much as possible to keep the piping simple.
void piping in which an air holdup can occur.
f installing the unit on a roof
bout lower-level hot water suppl
f the unit is installed on a roof to suppl water to the levels below make sure that the water pressure supplied
to the unit does not drop below 2 psi. t ma be necessar to install a pump s stem to ensure that the water
pressure is maintained at this level.
Check the pressure before putting the unit into operation.
ailure to suppl the proper pressure to the unit ma result in nois operation shorter lifetime of the unit and
ma cause the unit to shut down fre uentl .
Completel insulate
the water inlet and
outlet fittings.
nsulate the water
suppl valve completel .
Do not cover the water
drain plug with insulations
o th
can be drained.

17
Hot water piping
Do not use lead PVC iron or an piping which
has been treated with chromates boiler seal or
other chemicals.
The longer the piping the greater the heat loss.
Tr to make the piping as short as possible.
Use mi ing valves with low water resistance.
Use shower heads with low pressure loss.
f necessar use a pump or other means to
ensure that the suppl water pressure to the
inlet of the heater does not fall below 2 PS
when the ma imum amount of water is being
demanded. lso install a pressure meter on
the inlet. f this is not done local boiling will
occur inside the water heater causing abnormal
sounds and decreasing the durabilit of the heat
e changer.
reeze Pre ention
ree ing is prevented within the device automaticall unless the outside temperature without wind
is below - 0 (- 5 C).
*
When combustion air is supplied from the indoors the room temperature must be greater than 2 (0 C)
to prevent free ing and the room inside must not have negative pressure.
f this model is installed in an area where the outside temperature can approach free ing conditions
of - 0 (- 5 C) or below then additional free e protection measures must be used. or temporar
free e protection measures refer to the wner s Guide.
The free e prevention heaters will not prevent the plumbing e ternal to the unit from free ing.
Protect this plumbing with insulation heat tape or electric heaters solenoids or pipe covers.
n order for the free e prevention heaters to operate the water heater must have power at all times.
Supply water piping
Do not use PVC iron or an piping which has been
treated with chromates boiler seal or other chemicals.
Mount a check valve and a shut off valve (near the inlet).
n order for the client to use the water heater
comfortabl 8.1 to 4 1 kPa (14 to 70 PS ) of
pressure is needed from the water suppl .
e sure to check the water pressure. f the
water pressure is low the water heater cannot
perform to its full capabilit and ma become a
source of trouble for the client.
Drain piping
pansion water ma drop from the
pressure relief valve and wet the floor.
* Pressure relief valve (1)
nstall a drain hose (accessor ) to remove the
water. Prevent the drain hose from becoming
pinched.
* Pressure relief valve (2)
f necessar provide drain piping or use a
drain hose to remove the water.
Pressure relief valve (1) Pressure relief valve (2)

18
Water Treatment
Water Treatment S stem
Cit Water Suppl
Pressure
Relief
Valve
ot Water to i tures
Shutoff Valve
Drain
Cold to Water
eater
ptional Sediment
ilter
Water Treatment Device
Shutoff Valve
T pe of Water
ardness
evel Treatment Device lush re uenc *
T pe of Water
ardness
eel re tment e ice lush re uenc *
oft
0 1 gpg
1 3 gpg
0 17 mg
None None None
None
None
None
lightl r
17 51 mg
None None
oertel
r
r
3 7 gpg
51 120 mg
2 low or
c le hiel
2 low or
c le hiel
nce e r** nce e r
wice er
nce e r**
7 10 gpg
120 171 mg
Ver r
10 14 gpg
171 239 mg
2 low
2 low
2 low
2 low
2 low
2 low
re tment
e uire
E tremel
r
oft
lightl r
oertel
r
r
Ver r
E tremel
r
14 gpg
239 mg
0 1 gpg
1 3 gpg
0 17 mg
17 51 mg
3 7 gpg
51 120 mg
7 10 gpg
120 171 mg
10 14 gpg
171 239 mg
14 gpg
239 mg
re tment
e uire
re tment
e uire
re tment
e uire
* nst ll Norit sol tion V l es to llow for flushing.
** lushing is re uire if w ter tre tment e ice is not inst lle .
uggeste
uggeste
**
**
* nst ll Norit sol tion V l es to llow for flushing.
** lushing is re uire if w ter tre tment e ice is not inst lle .
esi enti l se re tment ui elines ommerci l se re tment ui elines
N
n less s
ter e ter
f this w ter he ter will be inst lle in n pplic tion where the suppl w ter is h r the w ter must
be tre te with either the Norit 2 low or c le hiel or w ter softener. efer to the below t bles
for suggeste tre tment n m inten nce me sures to be t en b se on the w ter h r ness le el.
m ge to the w ter he ter s result of w ter in e cess of 12 gpg 200 mg of h r ness is not
co ere b the Norit meric imite rr nt .
Note: Water softeners may be regulated by the local water jurisdiction, consult with the manufacturer
for co e si ing n inst ll tion
gui elines the below i gr m is for reference onl . or more
inform tion bout 2 low n c le hiel cont ct Norit meric t 866 766 7489.

1
ecircul tion stem
ombin tion ot ble ter n p ce e ting stem
ol ter uppl
sol tion
it *4
s uppl
ustt*3
ump ontrol ign l *2
el for ump
if l rger th n 85 tts
ot ter
ption l 8 10 llon
tor ge n
o lle i te col w ter s n wich
lobe
Vle
ump *1
E p nsion n
nst ll ccor ing
to loc l co e
i tures
ot ter eturn
ump
120V
105
Neutr l
roun
ie
sol tion
it *1
s uppl c flow re enter
option l
hec
Vle*3
ol ter
uppl
ption l
E p nsion n *6
i ing V l e *5
ot ter
ump *2
low witch *4
i tures
ir n ler
Notes
1. i e the pump to pro i e m imum of 2
7.5 min. through the s stem t 10 ft 3m of
he plus piping losses.
ust the flow using globe l e n erif the
flow r te with the m inten nce monitors.
2. ump ontrol ign l is the preferre metho
to control the recircul tion pump.
or pumps l rger th n 85 rel connection
must be use . f the ump ontrol ign l is not
use n u st t m be use to control the
pump.
3.
se n u st t if the w ter he ter is not controlling
the pump.
et the u st t to 10 5 below the set
output temper ture.
4. Norit recommen s the use of n sol tion it
with the inst ll tion.
hese its inclu e n integr te shut off n ser ice
l e with unions n pressure relief l e.
Notes
1. Norit recommen s the use of n sol tion it with
the inst ll tion.
hese its inclu e n integr te shut off n ser ice
l e with unions n pressure relief l e.
2. i e the pump to pro i e
m imum of 3
11.3 min. with he pressure e u l to the loss
through the w ter he ter n ir n ler.
3 . hec l e re uire if it is not inclu e with the pump.
4. et the flow switch to e cti te the ir n ler when
the omestic hot w ter flow re ches 3 11.3 min. .
ust s necess r to pre ent c cling.
5. f the s stem re uires w ter for sp ce he ting t higher
temper ture th n for other uses me ns such s
mi ing l e sh ll be pro i e to temper the w ter for
the other uses to help pre ent sc l ing.
7. he w ter he ter c nnot be use for sp ce he ting
pplic tions onl .
8. nl E w ter m be plumbe through
the w ter he ter.
6. E p nsion t n re uire if b c flow pre enter is inst lle .
se one well u st t
o el 6006 or 6006
u st t iring
N
n less s
ter e ter
N
n less s
ter e ter
11. Plumbing Applications

20
o not connect electric l power to the unit until ll electric l wiring h s been complete .
Consult a qualified electrician
for the electric l wor .
12. Electrical Wiring
his ppli nce must be electric ll groun e in ccor nce with loc l co es or in the bsence of loc l
co es with the N tion l Electric l o e N N 70. n n the l test 22.1 Electric l o e.
Caution: bel ll wires prior to isconnection when ser icing controls. iring errors c n c use
improper n ngerous oper tion.
Verif proper oper tion fter ser icing.
iel wiring to be performe t time of ppli nce inst ll tion.
isconnect ower
Electric l hoc r
Do not turn power on until electrical wiring is finished. Disconnect power before servicing.
Failure to do so may result in death or serious injury from electrical shock.
WARNING
Ground
o pre ent electric l shoc pro i e groun
with resist nce less th n 100 . n electrici n
shoul o this wor .
groun ing screw is pro i e on the b c in
the junction box.
o not connect the groun to the cit w ter
or g s piping. o not tie the groun to
telephone line.
Breaker Installation
ount e ice which shuts off the electric l
p th utom tic ll le ge bre er when
electric l le ge is etecte .
he electric l suppl re uire b the w ter he ter is
120V t 60 .
he power consumption m be up to 276 or higher if
using option l ccessories.
se n ppropri te circuit.
o not isconnect the power suppl when not in use. hen
the power is off the free e pre ention in the w ter he ter
will not cti te resulting in possible free ing m ge.
o not let the power cor cont ct
the g s piping.
ie the re un nt power cor
outsi e the w ter he ter. utting the
re un nt length of cor insi e the
w ter he ter m c use electric l
interference n f ult oper tion.
Electrost tic isch rge c n ffect electronic components. e prec utions to pre ent electrost tic isch rges from
personnel or h n tools uring the w ter he ter inst ll tion n ser icing to protect pro uct s electronic control.
CAUTION
1.Remove the screw (one) of the junction box and
open the cover of the junction box.
2. onnect the groun ing wire to the groun screw in
the co er.
3. rimp the out oor power c ble to the power c ble
of the unit.
unction o ower or
roun