Noritz NCC1991-DV 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
CONDENSING TANKLESS GAS WATER HEATER
NCC1991-DV (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
SBA8747
Rev. 11/11
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.
CAUTION
FOR USE IN 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.
Noritz America reserves the right to discontinue, or change at any
time, the designs and/or specifications of its products without notice.
*ENERGY STAR®applies when used in a combination potable
water heating and space heating system.
CERTIFIED
R
*SBA8747*
Low NOx
Approved by
SCAQMD
14 ng/J or 20 ppm
(Natural Gas Only)

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
1
Remote Controller
(See p. 28) Remote Controller
Cord (6ft (2m))
1
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
Remote Controller
Cord (26ft (8m))
QuickConnect Cord
(QC-2) 11
1
each
IsolationValves
(includespressure
reliefvalve)
Owner's Guide, Warranty,
Installation Manual
(this document)
Bird Screen for
4" (100mm) PVC
VT4-PVCS
Bird Screen for
3" (75mm) PVC
VT3-PVCS 2
2
3" (75mm)
PVC Terminal
VK3-H-PVC 1
1
PipeCover
(PC-3S-SUS)
Note: Additional vent pieces are available; consult the latest product catalogue for details.
3" (75mm) / 4" (100mm)
Horizontal Hood
Termination PVT-HL 2
1
each 1
1
System Controller Unit
(SCU-301-12M)
System Controller
(SC-301-6M)
SVConversion Kit
(#SV-CK-3)
•90 Elbow
(WithInlet Screen)
• InstallationManual
(CheckList)
Drain hose
(With clamp) 1
1
1
Neutralizer
(NT20A)
(For up to 16 water heaters)
Neutralizer
(NC-1)
(For 1 water heater)

3
G
Quick Connect
Cord
Remote Controller Cord Gas Supply Piping
Cold Water Supply
Hot Water
Remote Controller
Terminal Block
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.
Typical Plumbing
* When connecting two units, use only a
single remote controller.
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 excessively
cold temperatures.
Union
Make this distance as short
as possible.
* The hot water temperature
will become unstable as the
pipe length increases.
Distance at center: 20.3 - 36.3 in. (515 - 922mm)
Quick Connect Cord
Union
Gas Valve
Union
Shutoff Valve
Shutoff Valve
Hot Water
Shutoff Valve
Cold Water
Distance on sides
2 - 18 in. (50 - 457mm)
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.
The backflow preventer is
put up before it diverges.
Pressure
Relief Valve
The Quick Connect Cord is 6 ft.(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).

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
• Donot use for otherthanincreasing the temperature ofthewater supply, as unexpectedaccidents
mayoccur as a result.
Check Water Supply Quality
• Ifthe water supply isinexcess of 12 grainspergallon (200 mg/L) ofhardness,acidic or otherwise
impure,treat the water withapprovedmethods in order toensurefull warranty coverage.
WARNING
CAUTION
Check the Gas
• Checkthat the rating plateindicatesthe
correcttype of gas.
• Checkthat the gas supplylineis sized for
199,900Btuh.
Check the Power
• Thepower supply required is120VAC,at 60Hz.
Using the incorrect voltage mayresult in fireorelectricshock.
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 Replacement
• Thevent system will almostcertainlyneed to be replacedwhenthis appliance is beinginstalled.
Onlyuse vent materials thatarespecified in thisInstallationManualfor use onthisappliance. Refer
tothe "VentPipeInstallation" section fordetails. IfPVC,CPVC, or CategoryIVlistedpipe is already
installed,check for punctures, cracks,orblockages and consult withthevent pipe manufacturer
beforereusing.
Improper venting may result in fires,propertydamageor exposure to CarbonMonoxide.
Snow Precaution
• Ifthis product will beinstalledin an area wheresnowis known to accumulate,protectthe vent
terminationfrom blockage by snowdriftsor damage from snowfallingoffofroofs.

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 fromthewater heater may causediscolorationof
wallsand resinous materials, orcorrosionof aluminum materials.
DANGER
WARNING
CAUTION
Prohibited
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 thatthe exhaust flueterminationwill
havethe proper clearances accordingtothe 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.
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.
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
Distance from
the side
12" (300mm)
or more
2" (50mm)
or more
4" (100mm)
or more
3" (75mm) or more
3" (75mm) or more
8" (200mm)
or more
8" (200mm)
or more
<When the indoor air supply>
• 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 water heater.
Exhaust hood
Range
Dividing plate Water
heater
Cooking Equipment

8
Clearance Requirements from Vent Terminations to Building Openings
<When supplying combustion air from the indoors>
* 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.
Item
• 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
Outdoor Clearances to Opening
into Any Building
12" (300mm)
or more
12" (300mm)
or more
There must be no
building opening
within this area.
Flue terminal
12" (300mm)
or more
12" (300mm)
or more
Vent Clearances When Heater is In-
stalled Indoors
For installations in the USA,
• 4' below, 4' horizontally from, or 1'above any
door, operable window, or gravity air inlet into
any building.
3' above any forced air inlet within 10'.
For installations in Canada,
• 36" (900mm) below, horizontally from, or
above any door, operable window, or gravity
air inlet into any building.
6' (1.8m) from any forced air inlet.
Maintain the following clearances to any
opening in any building: Illustration
4' *
4' *
3' *
1' *
* Clearances for USA only.

9
Vent Terminal
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 feet 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
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)]
4’ (1.2m) below or to the side of
opening, or 1’ (0.3m)above opening
[36" (900mm)]
Air Supply Inlet
Area Where Terminal
is Not Permitted
Indoor Combustion Air
*
*
*
*
3' (0.9m) within a height 15' (4.5m)
above meter/regulator assembly
3' (0.9m)
3' above if within
10' [6' (1.8m)]
* [7' (2.1m***)]
* [12" (300mm)****]
*
12" [12" (300mm)]
12" [36" (900mm)]
4’ below or to the side of
opening, or 1’ above opening
[36" (900mm)] 12" [36" (900mm)]
Outdoor Combustion Air
(Direct Vent)
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.

10
7. Installation
Securing to the wall
IllustrationCheck
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
device.
• Make sure the unit is installed securely so that it will
not fall or move due to vibrations or earthquakes.
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.
3. 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
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.
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)
Location of Screw Hole
Locating Screw Holes
Installations at Elevations
Above 2,000 ft.
• 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 28 for the location of the
dip switch bank.
Tapping Screw
* Do not change any other dipswitches.
* High elevation adjustment.
65
2,001 - 4,000 ft (611 - 1,220m)
0 - 2,000 ft (0 - 610m)
ON= OFF=
4,001 - 6,000 ft (1,221 - 1,830m)
6,001 - 8,000 ft (1,831 - 2,440m)

11
Filling the condensate trap with water
The condensate trap can be filled before connecting the vent pipe.
Filling the condensate trap before vent pipe installation.
DANGER
Prior to initial start up, make sure that you fill the condensate trap with water.
This is to prevent dangerous exhaust gases from entering the building.
Failure to fill the condensate trap could result in severe personal injury or death.
Please follow one of the procedures described below to ensure that the condensate trap is filled with water.
1) Fill the condensate trap by pouring approx. 30 oz.(850ml) of water into the exhaust accessory on the top
of the appliance as illustrated below.
Or, if the vent pipe has already been installed:
2) After installing the drain pipe, make sure that the area around the appliance is well ventilated; open a
window or a door if necessary.
Then, operate the unit and verify that condensate is coming out of the drain pipe.
(During normal use of the water heater, condensate will begin to discharge from the drain pipe within
15 minutes of use. However, depending on the season and/or installation site conditions, it may take longer.)
Note: The condensate discharged from the water heater has a pH level of approximately 2-3.
If required by local code, the condensate must be neutralized prior to disposal into the sewer system.
Refer to pages 24-25 for additional details.
30 oz.
850ml
Intake
Exhaust

12
Maximum Vent Lengths
• This appliance has been designed to be vented
with either 3" (75mm) or 4" (100mm) PVC or
CPVC pipe.
Do not exceed the following maximum vent lengths:
* Not including the termination
Refer to page 16 for max. vent lengths
When using termination VK3-H-PVC
• Maintain the same vent pipe diameter from the
heater flue to the vent termination. The exhaust
and intake pipes must be the same vent pipe
diameter.
8. Vent Pipe Installation(Indoor Installation Only)
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.
• Under normal conditions, this appliance will not
produce an exhaust flue temperature in excess
of 149°F (65°C) and schedule 40 PVC pipe
may be used as the vent material. If the water
heater set temperature is 160°F (70°C) or
higher and there is a return line to the water
heater from either a recirculation pump or a
combination space heating system, schedule
40 or 80 CPVC may also be used. Refer to
page 14 for additional requirements.
• Make sure the vent system is gas tight and
will not leak.
• Support the vent pipe with hangers at regular
intervals as specified by these instructions or
the instructions of the vent manufacturer.
• 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 3' (0.9m).
• Do not store hazardous or flammable sub-
stances 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.
General Requirements
Clearances
PVC or CPVC has been approved for use on this
appliance with zero clearance to combustibles.
No. of Elbows Max. Straight Vent Length*
4 N/A 39' (11.7m)
3 16' (4.8m) 45' (13.5m)
2 22' (6.6m) 51' (15.3m)
1 28' (8.4m) 57' (17.1m)
Pipe diameter 3" (75mm) 4" (100mm)

13
Maximum Vent Length Adjustment Dipswitches
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
45
48
51
54
57
60
63
0.00
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
13.50
14.40
15.30
16.20
17.10
18.00
18.90
m10 234ftVent length* Elbows
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Number of
pieces**
3
30%
-3%
-3%
-5%
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
3
30%
-3%
-3%
-5%
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
3
30%
-3%
-3%
-5%
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
4
3
30%
-3%
-3%
-5%
3
3
3
4
4
4
4
4
4
4
4
4
4
4
3
30%
-3%
-3%
-5%
3
4
4
4
4
4
4
4
4
4
4
4
0
3
6
9
12
15
16
18
21
22
24
27
28
30
33
34
0.00
0.90
1.80
2.70
3.60
4.50
4.80
5.40
6.30
6.60
7.20
8.10
8.40
9.00
9.90
10.20
m10 23ftVent length*
3” Pipe Elbows
0
1
2
3
4
5
6
6
7
8
8
9
10
10
11
12
Number of
pieces**
1
10%
0%
-5%
-5%
1
1
1
1
2
2
2
2
2
2
2
2
2
2
1
10%
0%
-5%
-5%
1
1
2
2
2
2
2
2
2
2
2
1
10%
0%
-5%
-5%
2
2
2
2
2
2
2
2
0%
-5%
2
2
2
2
2
2
2
13
24
Short length using 4" (100mm)pipe
Short length using 3" (75mm)pipe
Long length using 3" (75mm)pipe Long length using 4" (100mm)pipe
Short length using 4" (100mm)pipe
Short length using 3" (75mm)pipe
Long length using 3" (75mm)pipe
Long length using 4" (100mm)pipe
**Table assumes straight vent pieces are 3’ (0.9m) each.
Shorter or longer vent pieces may also be used up to the maximum
allowed vent length.
Do not change any other dipswitches.
Vent length condition.
178
ON= OFF=
2
3
4
4” Pipe
* Not including the termination.
* Not including the termination.
Refer to page 16 for max. vent lengths
when using termination VK3-H-PVC.
<Maximum Vent Length and Reduced Input Configurations>
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 " 1 short length using 3" (75mm) pipe" condition. When adjusting
the dip switches for longer vent runs, the BTUH input of the appliance will be reduced by up to 5%.
- Two 90° elbows, maximum length = 3 ft. (0.9m)
(with dip switches set at " 1 short length using 3" (75mm) pipe" condition)
- Two 90° elbows, maximum length = 51 ft. (15.3m)
(with dip switches set at " 4 long length using 4" (100mm) pipe" 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 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 28 for the location of the dip switch bank.
The power must be unplugged
when adjusting the dip switches
to switch the airflow amount.

14
WARNING
CARBON MONOXIDE POISONING
Failure to properly seal the vent system could
cause flue products to enter the living space.
Item Material United States Canada
Exhaust Vent/Air Intake Schedule 40 PVC ANSI/ASTM D1785
ULC S636 Certified
Materials Only
PVC-DWV ANSI/ASTM D2665
Schedule 40 CPVC ANSI/ASTM F441
Pipe Cement/Primer PVC ANSI/ASTM D2564
CPVC ANSI/ASTM F493
Note: Do Not Use Cellular Foam Core Pipe
PVC/CPVC Installation Instructions
• Use only solid PVC or CPVC schedule 40 pipe. Cellular foam core piping is not allowed.
•
•
In Canada, plastic vent systems must be certified to ULC S636. The components of the certified
vent system must not be interchanged with other vent systems or unlisted pipe/fittings.
• In Canada, specified primers and glues of the ULC S636 certified vent system must be from a
single system manufacturer and not intermixed with other system manufacturer’s vent system
parts.
• Follow all general venting guidelines as outlined on this page.
• The pipe shall be installed so that the first 3’ (0.9m) of pipe from the appliance flue outlet is readily
accessible for visual inspection.
• When preparing and assembling the pipe, follow instructions as provided by the pipe
manufacturer. In general, the following practices must be observed:
o Squarely cut all pieces of pipe.
o Remove all burs and debris from joints and fittings.
o All joints must be properly cleaned, primed, and cemented. Use only cement and primer
approved for use with the pipe material as outlined in the above table.
•
• PVC or CPVC pipe has been approved for use on this appliance with zero clearance to combustibles.
All piping must be fully supported. Use pipe hangers at a minimum of 3’ (0.9m) intervals. Do not use
the water heater to support the vent piping.
3" or 4" schedule 80 pipe may also be used on this appliance, however the BTUH input of the
appliance will be reduced by up to 5%.
16' (4.8m)
N /A
No. of Elbows
* Not including the termination
22' (6.6m)
3
4
2
1 28' (8.4m)
45' (13.5m)
39' (11.7m)
51' (15.3m)
57' (17.1m)
• Do not exceed the following maximum vent lengths:
Venting With PVC or CPVC
This appliance can be vented with non cellular core plastic pipe materials as specified in the below table.
Vent installations in Canada which utilize plastic vent systems must comply with ULC S636.
•
• Abird screen must be installed on the vent terminations to prevent debris or animals from entering the
piping. These screens are not supplied with the water heater and must be purchased separately
(part #VT4-PVCS, use part #VT3-PVCS when using 3" (75mm) PVC or CPVC).
When attaching the piping to the water heater, use the appropriate primer and cement to ensure a
proper seal.
4" (100mm) Pipe*3" (75mm) Pipe*
Refer to page 16 for max. vent lengths
when using termination VK3-H-PVC.

15
Vertical Vent Termination- PVC/CPVC Materials Only
•
•
•
•
•
•
•
•
Horizontal Vent Termination- PVC/CPVC Materials Only
•
•
•
•
•
•
•
•
Insert Bird
Screen* in
End of Each
90 Elbow
Hanger
Straps
**1' mini
* Not supplied with water heater,
order separately.
mum recommended,
but not required.
3 ft. Min.
3 ft. Min.
FirestopFirestop
Firestop/Support
Roof
Flashing
Roof
Flashing
Hanger
Strap
**1'
Minimum
**1'
Minimum
Support
Slope
Slope vent
Upwards
Intake
Exhaust
vent
Upwards
Intake Exhaust
Insert Bird Screen*
in End of 45 Elbow
12" over maximum
snow level
or 24", whichever
is greater.
12" over maximum
snow level
or 24", whichever
is greater.
Insert Bird
Screen* in
End of
90 Elbow
Storm
Collar
Storm
Collar
As illustrated on the left, make sure to keep a
distance of 3' (0.9m) or wider between the intake and
exhaust when installing the vent piping.
The PVT-HL termination may be used in place of elbows
as the horizontal vent terminations. It is not necessary to
use bird screens with the PVT-HL 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 meter, service regulator etc.
Terminate 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" upwards for every
12" (300mm) 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.
As illustrated on the left, make sure to keep a distance
of 3' (0.9m) or wider between the intake and exhaust
when installing the vent piping.
Terminate at least 6' (1.8m) from the combustion air
intake of any appliance, and 3' (0.9m) 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
8' (2.4m) from a vertical wall or similar obstruction,
terminate above the roof at least 2' (0.6m), but not
more than 6' (1.87m), in accordance with the National
Fuel Gas Code ANSI Z223.1/NFPA 54.
Provide vertical support every 3' (0.9m) or as required
by the vent pipe manufacturer's instructions.
A short horizontal section is recommended to prevent
debris from falling into the water heater.
When using a horizontal section, slope the horizontal
vent 1/4” upwards for every 12” (300mm) toward the
termination to drain condensate.
**1' minimum recommended,
but not required.
*
Not supplied with water heater,
order separately.
Vent Pipe Installation

16
No. of
Elbows
3
2
1
4
Max. Straight Vent Length**
3" (75mm) PVC or CPVC
Max. Straight Vent Length**
4" (100mm) PVC or CPVC
** Not including the concentric termination
16' (4.8m)
N / A
22' (6.6m)
28' (8.4m)
30' (9.0m)
N / A
36' (10.8m)
42' (12.6m)
Maximum Vent LengthAdjustment Dip switches.
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
0.00
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
m10 23ft
Vent length*** Elbows
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
N /A
Number of
pieces****
-5%
-5%
3
30%
3
3
4
4
4
4
4
4
4
4
4
4
4
3
30%
4
4
4
4
4
4
4
4
4
4
4
4
4-3%
-3%
-3%
-3%
-3%
-5%
4
4
4
4
4
4
4
4
4
4” Pipe
<Maximum Vent Length and Reduced Input Configurations>
*** Refer to page 13 for 㧟" pipe Maximum Vent Length Adjustment Dipswitches table.
3
4
Short length using 4" (100mm)pipe
Long length using 4" (100mm)pipe
****Table assumes straight vent pieces are 3’ (0.9m) each.
Shorter or longer vent pieces may also be used up to the maximum
allowed vent length.
•
•
•
•
•
•
•
Hanger
3" (75mm) or
4" (100mm)
Intake*
Horizontal Vent Termination- 3" (75m) Concentric PVC/CPVC Termination
3" (75m m ) or
4" (100m
m )
Exhaust*
Straps
The concentric termination may be shortened,
but not lengthened from its original factory
supplied length.
The concentric termination may only be used
for horizontal terminations.
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 meter, service regulator etc.
Terminate 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" upwards for every
12" (300mm).
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.
Slope vent
Upwards
* 4" (100mm) pipe requires the use of a reducing coupling
just prior to the termination.
1" (25mm)
Minimum
Insert Bird Screen
in End of Termination
•
There must be a minimum of 1" (25mm) clearance
between the outside wall and the air intake section
of the termination as illustrated on the left.
•
•
•
3" (75mm) or 4" (100mm) PVC or CPVC pipe
may be used with the concentric termination.
Maintain the same vent pipe diameter from the
water heater flue to the termination.
Do not exceed the maximum vent lengths as
specified in this section.
When using 4" (100mm) pipe, it will be necessary
to use 4" (100mm) x 3" (75mm) reducing couplings
and a short section of 3" (75mm) pipe to connect to
the termination.
Use no more than a 6" (150mm) section of pipe to
make the connection between the reducing
couplings and the termination.
•
Install a securing strap to prevent movement of
the termination.
Strap

17
Vertical Vent Termination- PVC/CPVC Materials Only
Firestop
Firestop/Support
Roof
Flashing
Storm
Collar
Hanger
Strap
Horizontal Vent Termination- PVC/CPVC Materials Only
Hanger
Straps
**1' (0.3m) Minimum
Slope vent
Upwards
**1' (0.3m) Minimum
* Not supplied with water
heater, order separately.
recommended, but not required.
Insert Bird
Screen* in
Each End
of Tee
Support
Insert Bird
Screen* in
End of 45
Elbow
Slope vent
Upwards
Pipe Material PVC or CPVC
* Not supplied with water
heater, order separately.
**1' (0.3m)
Minimum
**1' (0.3m) minimum
recommended, but not required.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
A tee, 45 elbow, or the PVT-HL termination may be used
for the vent termination. It is not necessary to use bird
screens with the PVT-HL 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
meter, service regulator etc.
Terminate at least 3' (0.9m) above any forced air inlet within
10' (3m) , 4' (1.2m) below, 4' (1.2m) horizontallyfrom 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" upwards for every 12" (300mm)
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.
When installed in a manufactured home, all combustion air
must be supplied from the outdoors as shown on pages 15 - 16.
Terminate at least 6' (1.8m) from the combustion air
intake of any appliance, and 3' (0.9m) 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
8' (2.4m) from a vertical wall or similar obstruction,
terminate above the roof at least 2' (0.6m), but not
more than 6' (1.87m), in accordance with the National
Fuel Gas Code ANSI Z223.1/NFPA 54.
Provide vertical support every 3' (0.9m) or as required
by the vent pipe manufacturer's instructions.
A short horizontal section is recommended to prevent
debris from falling into the water heater.
When using a horizontal section, slope the horizontal
vent 1/4” upwards for every 12” (300mm) toward the
termination to drain condensate.
When installed in a manufactured home, all combustion air
must be supplied from the outdoors as shown on page 15.
Exhaust
Intake
Exhaust
Intake
90 Elbow
Inlet screen
SV Conversion Kit
Accessory
(#SV-CK-3)
90 Elbow
Inlet screen
SV Conversion Kit
Accessory
(#SV-CK-3)
Max. Straight Vent Length
3 45' (13.5m)
No. of Elbows
3" (75mm) Pipe 4" (100mm) Pipe
2 51' (15.3m)
1
*** Not including the termination. 57' (17.1m)
***
4 39' (11.7m)
16' (4.8m)
22' (6.6m)
28' (8.4m)
N/A
Vent Pipe Installation (When supplying combustion air from the indoors (SV, non-direct vent))
• Disconnect power and turn ON dip switch 3 if combustion air will be
supplied form the indoors as illustrated to the right. Refer to page 28 for
the location of the dip switch bank.
• SV Conversion kit #SV-CK-3 is required for the air intake.
* Dip switch No.3 is turned on.
Failure to perform the above 2 steps could result in a fire or explosion causing
property damage, personal injury or death.
Refer to the instructions provided with the conversion kit for additional details.
WARNING

18
• Provide two permanent openings to allow
circulation of combustion air.
• Make each opening 199 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 24" (600mm) 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.
Supply combustion air to the units as per the National Fuel Gas Code, ANSI Z223.1
and in Canada, in accordance with CSA-B149.1.
Combustion Air
Openings supplying indoor air
10" (250mm)
20" (500mm)
10" (250mm)
20" (500mm)
Provide adequate combustion air so as to not create negative pressure within the building.

19
Gas Meter
Select a gas meter capable of supplying 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 flex lines are not recommended unless
they are rated for 199,900 btuh.
• Install a gas shutoff valve on the supply line.
• Use only approved gas piping materials.
Follow the instructions from the gas supplier.
Gas Pressure
Size the gas line according to total btuh demand
of the building and length from the meter or
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
9. Gas Piping
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 1⁄2psig (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 1⁄2psig (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.
Natural Gas
Meter **See next page for the pipe capacity charts.
Noritz Condensing Tankless Gas Water Heater
(199,900 Btuh)
Clothes Dryer
(35,000 Btuh)
Barbecue
(50,000 Btuh)
Gas Range Stove
(65,000 Btuh)
10' (3m)
10' (3m)
10' (3m)
10' (3m)
5' (1.5m)
5' (1.5m)
5' (1.5m)
5' (1.5m)
Gas Fireplace
(25,000 Btuh)
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 Gas Line
Sample Calculation
Outlet A: 45' (13.5m) (Use 50' (15m)), 50,000 Btuh requires 1/2"
Outlet B: 40' (12m), 65,000 Btuh requires 1/2"
Section 1: 45' (13.5m) (Use 50' (15m)), 115,000 Btuh requires 3/4"
Outlet C: 30' (9m), 35,000 Btuh requires 1/2"
Section 2: 45' (13.5m) (Use 50' (15m)), 150,000 Btuh requires 3/4"
Outlet D: 25' (7.5m) (Use 30' (9m)), 25,000 Btuh requires 1/2"
Section 3: 45' (13.5m) (Use 50' (15m)), 175,000 Btuh requires 1"
Outlet E: 25' (7.5m) (Use 30' (9m)), 199,900 Btuh requires 3/4"
Section 4: 45' (13.5m) (Use 50' (15m)), 374,900 Btuh requires 1-1/4"
Section 3 Section 2 Section 1
Outlet A
Outlet B
Outlet C
Outlet D
Outlet E
5' (1.5m)5' (1.5m)
Section 4
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.

20
Maximum Natural Gas Delivery Capacity in Cubic Feet per Hour (0.60 Specific Gravity, 0.5" WC Pressure Drop)
Contact the Gas Supplier for Btu/Cubic Ft. of the Supplied Gas. 1000 BTU/Cubic Ft. is a Typical Value
Maximum Liquefied Petroleum (Undiluted) Delivery Capacity in Thousands of Btuh (0.5" WC Pressure Drop)
Length in Feet
Length in Feet
Pipe
Size
Pipe
Size
1/2"
1/2"
3/4"
3/4"
1"
1"
1 1/4"
1 1/4"
1 1/2"
1 1/2"
2"
2"
2 1/2"
3"
3 1/2"
4"
10' (3m) 20' (6m) 30' (9m)
40' (12m) 50' (15m) 60' (18m) 70' (21m) 80' (24m) 90' (27m) 100' (30m) 125' (37.5m)
10' (3m) 20' (6m) 30' (9m) 40' (12m) 50' (15m) 60' (18m) 70' (21m) 80' (24m) 90' (27m) 100' (30m) 150' (45m) 200' (60m)
10' (3m) 20' (6m) 30' (9m) 40' (12m) 50' (15m) 60' (18m) 70' (21m) 80' (24m) 90' (27m) 100' (30m) 150' (45m) 200' (60m)
10' (3m) 20' (6m) 30' (9m) 40' (12m) 50' (15m) 60' (18m) 70' (21m) 80' (24m) 90' (27m) 100' (30m) 150' (45m) 200' (60m)
125' (37.5m)
174
363
684
1404
2103
4050
6455
11,412
16,709
23,277
119
249
470
965
1445
2784
4437
7843
11,484
15,998
96
200
377
775
1161
2235
3563
6299
9222
12,847
Adapted from UPC 1997
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
358
536
1033
1646
2910
4261
5936
275
567
1071
2205
3307
6221
189
393
732
1496
2299
4331
152
315
590
1212
1858
3465
129
267
504
1039
1559
2992
114
237
448
913
1417
2646
103
217
409
834
1275
2394
96
196
378
771
1181
2205
89
185
346
724
1086
2047
83
173
322
677
1023
1921
78
162
307
630
976
1811
69
146
275
567
866
1606
63
132
252
511
787
1496
55
112
213
440
675
1260
Maximum Capacity of Flex TracPipe in Cubic Feet per Hour of Natural Gas (0.60 Specific Gravity, 0.5" WC Pressure Drop)
Length in Feet
Pipe
Size
3/4"
1"
1 1/4"
1 1/2"
2"
206
383
614
1261
2934
147
269
418
888
2078
121
218
334
723
1698
105
188
284
625
1472
94
168
251
559
1317
86
153
227
509
1203
80
141
209
471
1114
75
132
194
440
1042
71
125
181
415
983
67
118
171
393
933
55
94
137
320
762
48
82
116
277
661
R
Maximum Capacity of Flex TracPipe in Thousands of Btuh Liquefied Petroleum ( 0.5" WC Pressure Drop)
Length in Feet
Pipe
Size
3/4"
1"
1 1/4"
1 1/2"
2"
325
605
971
1993
4638
232
425
661
1404
3285
191
344
528
1143
2684
166
297
449
988
2327
149
265
397
884
2082
136
241
359
805
1902
126
222
330
745
1761
118
208
307
696
1647
112
197
286
656
1554
106
186
270
621
1475
87
143
217
506
1205
76
129
183
438
1045
R
** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.
** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.
Maximum Capacity for Gas Flex Connectors in Cubic Feet per Hour of Natural Gas (0.60 Specific Gravity, 0.5" WC Pressure Drop)
Length in Inches
Pipe
Size
1/2"
3/4"
1"
1 1/4"
12" (300mm) 24" (600mm) 36" (900mm) 48" (1200mm) 60" (1500mm) 72" (1800mm)
12" (300mm) 24" (600mm) 36" (900mm) 48" (1200mm) 60" (1500mm) 72" (1800mm)
180 150
290
581
1470
125
255
512
1200
106
215
442
1130
93
197
397
960
86
173
347
930
Length in Inches
Pipe
Size
1/2"
3/4"
1"
1 1/4"
288 240
465
930
2352
200
409
825
1920
169
344
708
1808
149
315
638
1536
137
278
556
1488
Maximum Capacity for Gas Flex Connectors in Thousands of Btuh Liquefied Petroleum ( 0.5" WC Pressure Drop)
** For reference only. Please consult gas pipe manufacturer for actual pipe capacities.
TracPipe® is a registered trademark of Omega Flex.
Gas Line Sizing for a Noritz Condensing Tankless Gas Water Heater