HTP CG125N73 Installation manual

120 Braley Rd. P.O. Box 429 East Freetown, MA 02717-0429 www.htproducts.com
LP-436 REV. 3.21.14
Commercial Gas-Fired
Water Heater
INSTALLATION
START-UP
MAINTENANCE
PARTS
Models
CG125N73, CG150N73, CG199N73
CG199N73X*, CG250N65, CG300N65
*A Suffix of “X” Denotes Model Set for Low NOx Operation
This manual must be used by a qualified installer/service technician. Read all instructions in this manual before installing. Perform steps
in the given order. Failure to comply could result in substantial property damage, severe personal injury, or death.
NOTICE: HTP reserves the right to make product changes or updates without notice and will not be held liable for typographical errors
in literature.
The surfaces of these products contacted by consumable water contain less than 0.25% lead by weight, as required by the Safe
Drinking Water Act, Section 1417.
NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.
For your records, write the model and serial number here: MODEL #_____________ Serial #_________________

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LP-436 REV. 3.21.14
IF THE INFORMATION IN THIS MANUAL IS NOT FOLLOWED EXACTLY, A FIRE OR EXPLOSION MAY RESULT, CAUSING
PROPERTY DAMAGE, PERSONAL INJURY, OR LOSS OF LIFE. DO NOT STORE GASOLINE OR OTHER FLAMMABLE VAPORS
AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
Do not touch any electrical switch.
Do not use any phone in your building.
Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire department. Installation and service must be provided by a qualified installer,
service agency, or the gas supplier.

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LP-436 REV. 3.21.14
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk
levels, or to important product information.
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.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property
damage.
FOREWORD
This manual is intended to be used in conjunction with other literature provided with the Commercial Gas-Fired Water Heater. This
includes all related control information. It is important that this manual, all other documents included with this system, and additional
publications including the National Fuel Gas Code, ANSI Z223.1 / NFPA 54 (in Canada –CGA No. B149), be reviewed in their entirety
before beginning any work.
Installation should be made in accordance with the regulations of the local code authorities and utility companies which pertain to this
type of water heating equipment.

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LP-436 REV. 3.21.14
FOR THE INSTALLER
This manual must only be used by a qualified heating installer/service technician. Read all instructions in this manual before installing.
Perform steps in the order given. Failure to comply could result in severe personal injury, death or substantial property damage.
This appliance must be installed by qualified and licensed personnel. The installer should be guided by the instructions furnished with
the boiler, and with local codes and utility company requirements. In the absence of local codes, preference should be given to the
National Fuel Gas Code, ANSI Z223.1-2002.
INSTALLATIONS MUST COMPLY WITH:
Local, state, provincial, and national codes, laws, regulations and ordinances.
The latest version of the National Fuel Gas Code, ANSI Z223.1, from American Gas Association Laboratories, 8501 East Pleasant
Valley Road, Cleveland, OH 44131.
In Canada –CGA No. B149 (latest version), from Canadian Gas Association Laboratories, 55 Scarsdale Road, Don Mills, Ontario,
Canada M3B 2R3. Also, Canadian Electrical Code C 22.1, from Canadian Standards Association, 5060 Spectrum Way, Suite 100,
Mississauga, Ontario, Canada L4W 5N6.
Code for the installation of Heat Producing Appliances (latest version), from American Insurance Association, 85 John Street, New
York, NY 11038.
The latest version of the National Electrical Code, NFPA No. 70.
NOTE: The gas manifold and controls met safe lighting and other performance criteria when undergoing tests specified in ANSI
Z21.10.3 –latest edition.
TABLE OF CONTENTS
PART 1 –GENERAL SAFETY INFORMATION..........................................................................................................................4
A. PRECAUTIONS..........................................................................................................................................................................4
B. IMPROPER COMBUSTION........................................................................................................................................................5
C. GAS............................................................................................................................................................................................5
D. WHEN SERVICING THE HEATER.............................................................................................................................................5
E. WATER QUALITY.......................................................................................................................................................................5
F. OPTIONAL EQUIPMENT............................................................................................................................................................6
PART 2 –INSTALLATION INSTRUCTIONS...............................................................................................................................7
PART 3 –OPERATING INSTRUCTIONS..................................................................................................................................19
PART 4 –GENERAL MAINTENANCE......................................................................................................................................20
PART 5 –TROUBLESHOOTING GUIDE..................................................................................................................................25
MAINTENANCE NOTES..................................................................................................................................................................33
HTP CUSTOMER INSTALLATION RECORD FORM......................................................................................................................34
PART 1 –GENERAL SAFETY INFORMATION
A. PRECAUTIONS
INSTALLER –Read all instructions in this manual before installing. Perform steps in the order given.
USER –This manual is for use only by a qualified heating installer/service technician. Have this heater serviced/inspected by a
qualified service technician annually.
FAILURE TO ADHERE TO THE GUIDELINES ON THIS PAGE CAN RESULT IN SUBSTANTIAL PROPERTY DAMAGE, SEVERE
PERSONAL INJURY, OR DEATH.

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LP-436 REV. 3.21.14
If the heater is exposed to the following, do not operate until all corrective steps have been made by a qualified serviceman:
1. FIRE
2. DAMAGE
3. WATER
Any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee. DO
NOT install or attempt to repair any damaged component or parts. If you detect any damage, contact the dealer where the water heater
was purchased or the manufacturer listed on the warranty.
DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN UNDERWATER. Immediately call a qualified service technician. Replace
any part of the control unit that has been under water.
B. IMPROPER COMBUSTION
Do not obstruct the flow of combustion and ventilating air. Adequate air is necessary for safe operation.
C. GAS
Should overheating occur or gas supply fail to shut off, turn off the manual gas control valve to the water heater. Ensure that the type of
gas supplied corresponds to that which is marked on the rating plate and main gas valve of the water heater.
D. WHEN SERVICING THE HEATER
To avoid electric shock, disconnect electrical supply before performing maintenance.
To avoid severe burns, allow heater to cool.
Do not use petroleum-based cleaning or sealing compounds in a heater system. Gaskets and seals in the system may be
damaged. This can result in substantial property damage.
Do not use “homemade cures” or “heater patent medicines”. Substantial property damage, damage to heater, and/or serious
personal injury may result.
E. WATER QUALITY
Water Chemistry
Chemical imbalance of the water supply may affect efficiency and cause severe damage to the water heater and associated equipment.
HTP recommends having water quality professionally analyzed to determine whether it is necessary to install a water softener. It is
important that the water chemistry on both the domestic hot water and central heating sides are checked before installing the water
heater, as water quality will affect the reliability of the system. Failure of a water heater due to lime scale build-up on the heating
surface, low pH, or other chemical imbalance IS NOT covered by the warranty.
Operating temperatures above 135oF will further accelerate the build-up of lime scale on the heating surface and may shorten the
service life of the water heater. Failure of a heat exchanger due to lime scale build-up on the heating surface, low pH, or other chemical
imbalance IS NOT covered by the warranty.
Outlined on the following page are water quality parameters which need to be met in order for the system to operate efficiently for many
years.
Water Hardness
Water hardness is mainly due to the presence of calcium and magnesium salts dissolved in water. The concentration of these salts is
expressed in mg/L, ppm, or grains per gallon as a measure of relative water hardness. Grains per gallon is the common reference
measurement used in the U.S. water heater industry. Hardness expressed as mg/L or ppm may be divided by 17.1 to convert to grains
per gallon. Water may be classified as very soft, slightly hard, moderately hard, or hard based on its hardness number. The minerals in
the water precipitate out as the water is heated and cause accelerated lime scale accumulation on a heat transfer surface. This lime
scale build-up may result in premature failure of the heat exchanger. Operating temperatures above 135oF will further accelerate the
build-up of lime scale on the heating surface and may shorten the service life of the water heater.
Water that is classified as hard and very hard must be softened to avoid heat exchanger failure.

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LP-436 REV. 3.21.14
CLASSIFICATION
MG/L OR PPM
GRAINS/GAL
Soft
0 –17.1
0 - 1
Slightly Hard
17.1 –60
1 –3.5
Moderately Hard
60 –120
3.5 –7.0
Hard
120 –180
7.0 –10.5
Very Hard
180 and over
10.5 and over
If the hardness of the water exceeds the maximum level of 7 grains per gallon, water should be softened to a hardness level no lower
than 5 grains per gallon. Water softened as low as 0 to 1 grain per gallon may be under-saturated with respect to calcium carbonate,
resulting in water that is aggressive and corrosive.
pH of Water
pH is a measure of relative acidity, neutrality or alkalinity. Dissolved minerals and gases affect water pH. The pH scale ranges from 0 to
14. Water with a pH of 7.0 is considered neutral. Water with a pH lower than 7 is considered acidic. Water pH higher than 7 is
considered alkaline. A neutral pH (around 7) is desirable for most potable water applications. Corrosion damage and heater failures
resulting from water pH levels of lower than 6 or higher than 8 ARE NOT covered by the warranty. The ideal pH range for water
used in a storage tank or a water heater system is 7.2 to 7.8.
Total Dissolved Solids
Total Dissolved Solids (TDS) is a measurement of all minerals and solids dissolved in a water sample. The concentration of total
dissolved solids is usually expressed in parts per million (ppm).
Water with a high TDS concentration will greatly accelerate lime and scale formation in the hot water system. Most high TDS
concentrations precipitate out of the water when heated. This can generate a scale accumulation on the heat transfer surface that will
greatly reduce the service life of a water heater. This scale accumulation can also impede the ability of the heat exchanger to transfer
heat into the water. A heat exchanger damaged or blocked by lime/scale accumulation must be replaced.
The manufacturer of the water heater has no control of water quality, especially TDS levels in your system. Total dissolved solids in
excess of 2,000 ppm will accelerate lime and scale formation in the heat exchanger. Heat exchanger failure due to total dissolved solids
in excess of 2,000 ppm is a non-warrantable condition. Failure of a water heater due to lime scale build up on the heating surface
IS NOT covered by the warranty.
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6-8
TDS: 2000 ppm
Sodium: 20 mGL
F. OPTIONAL EQUIPMENT
Below is a list of optional equipment available from HTP. These additional options may be purchased through your HTP distributor.
High Altitude Kit
Part # 8800P-024 –125 kBTU
Part # 8800P-025 –150 kBTU
Part # 8800P-026 –199.9 kBTU
Part # 8800P-027 –250 kBTU
Part # 8800P-028 –300 kBTU
Power Venter
Part # 6060-200 –125 kBTU
Part # 6060-201 –150 –300 kBTU models
Vent Termination Kit
Part # 6060-202 –125 kBTU
Part # 6060-203 –150 –300 kBTU models

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LP-436 REV. 3.21.14
PART 2 –INSTALLATION INSTRUCTIONS
Specifications and Dimensions
MODEL
STORAGE
CAPACITY
GALLONS (LITERS)
FUEL
TYPE
INPUT
(BTU)
RECOVERY 90oF / 50oC
GALLONS (LITERS) PER
HOUR
SHIPPING WEIGHT
LBS. (EST.)
CG125N73
72 (272)
N
125,000
135 (511)
429
CG150N73
70 (265)
150,000
162 (613)
CG199N73(X)
68 (257)
199,900
215 (814)
CG250N65
60 (227)
250,000
269 (1018)
465
CG300N65
55 (208)
300,000
323 (1223)
MODEL DIMENSIONS IN INCHES
MODEL
A
B
C
D
E1
E2
F
H
J
K
CG125N73
15 ¾
52 ½
64 1/8
5 7/8
25 ¼
58 ¼
69 ¼
5
40.3o
51.2o
CG150N73
70 7/8
6
CG199N73(X)
CG250N65
52 1/8
7
CG300N65
71 5/8
8
Table 1 –Specifications and Dimensions –NOTE: All Water Heaters Shipped to Operate on Natural Gas –A suffix of “X”
denotes model set for Low NOx operation
Location
This water heater should be located in a clean, dry location, as close as possible to the chimney and to the main use of hot water. This
location must not be subject to freezing temperatures. Make sure the cold water piping is not located directly above the main gas valve
or any other electrical control. This will prevent water and condensation from dripping on the main gas valve during installation and
operation.
The water heater should be positioned so there is easy access to the main gas valve, flue damper, junction box, temperature and
pressure relief valve, and drain valve. Space must be provided at the front of the water heater so that the burner tray assembly can
slide out for service.

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LP-436 REV. 3.21.14
The water heater must be located close to a suitable free-
flowing floor drain. Where a floor drain is not adjacent to the
water heater, a suitable drain pan must be installed under the
water heater. See Figure 10 for proper installation. The drain
pan should be at least 4” (10.2 cm) larger than the diameter of
the water heater, and at least 1” (2.5 cm) deep, providing
access to the drain valve. This pan must not restrict the flow of
ventilation and combustion air. This pan must be piped to a
suitable drain to prevent damage to property in the event of a
water leak from the piping, the temperature and pressure relief
valve, or the water heater. Failure to follow this warning could
result in property damage, severe personal injury, or death.
All water heaters will leak. The manufacturer, based on
national building codes, has given the necessary
instructions to prevent damage to the building. Under no
circumstances is the manufacturer to be held liable for any
water damage in connection with this water heater. See
Figure 10 for proper installation.
This water heater IS NOT design certified for installation in a
manufactured (mobile) home or for installation outdoors.
Failure to follow this warning could result in property damage,
severe personal injury, or death.
This water heater is approved for installation on either a
combustible or non-combustible floor. However, should this water
heater be installed directly on carpeting, the carpeting must be
protected by a wood or metal panel beneath the water heater.
This panel must extend at least 3” (7.6 cm) beyond the width and
depth of the water heater. Should the water heater be installed in
an alcove or closet, the entire floor area must be covered by the
panel. The panel must be strong enough to carry the weight of the
water heater when it is full of water (CG-73 = 1040 lbs., CG-65 =
1010 lbs.)
Minimum Clearances
The minimum clearances from combustible materials for this
water heater are: 6” (15.2 cm) from the sides and rear, 24” (61
cm) from the front, and 18” (45.7 cm) from the top.
Combustion and Ventilation Air Supply
In order for the water heater to operate properly, it must be
supplied with an uninterrupted flow of clean combustion and
ventilation air. The area around the water heater must always be
kept clear so that the flow of combustion and ventilation air is not
blocked. An inadequate supply of air to the water heater will
produce a bright yellow burner flame, causing sooting in the
combustion chamber, on the burners, and in the flue tubes. This
can result in damage to the water heater and serious bodily injury
if not corrected.
Combustion and ventilation air requirements are determined by
the water heater location. Water heaters are installed in either
open (unconfined) spaces or smaller (confined) spaces, such as
closets or small rooms.
Requirements for Unconfined Spaces
An unconfined space is an area with at least 50 cubic feet for each 1,000 BTU/H of the total input rating for all gas-fired appliances
installed in that space. Water heaters installed in unconfined spaces do not usually require outdoor air to function properly. However, in
buildings with tight construction (heavy insulation, vapor barriers, weather stripping, etc.), and particularly in modern buildings,
Figure 1 –Minimum Clearances
Figure 2 –All Air from Inside the Building
Figure 3 –Communicating Directly with the Outdoors

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LP-436 REV. 3.21.14
additional fresh air may need to be provided. For instructions
on obtaining additional air supply, see the requirements for
confined spaces.
Requirements for Confined Spaces
A confined space is an area where the volume is less than 50
cubic feet for each 1,000 BTU/H of the total input rating for all
gas appliances installed in that space. Water heaters installed
in confined spaces require additional combustion and
ventilation air. This can be provided in two ways:
1. All Air from Inside the Building
The confined space shall be provided with two permanent
openings communicating directly with one or more rooms of
sufficient volume, so that the combined volume of all spaces
meets the criteria for an unconfined space. The total input
rating of all gas appliances installed in the combined space
shall be considered in making this determination.
Each opening shall have a minimum free area of one
square inch per 1,000 BTU/H of the total input rating of all gas
appliances in the confined space, but not less than 100 square
inches. One opening shall commence within 12” (30.5 cm) of the
top and one within 12” (30.5 cm) of the bottom of the enclosure.
See Figure 2.
2. All Air from Outdoors
The confined space shall be provided with two permanent
openings, one commencing within 12” (30.5 cm) of the top and
one commencing within 12” (30.5 cm) of the bottom of the
enclosure. The openings shall communicate directly, or by
ducts, with the outdoors or spaces (crawl or attic) that freely
communicate with the outdoors.
a. When communicating directly with the outdoors, each
opening shall have a minimum free area of one square inch per
4,000 BTU/H of the total input rating of all gas appliances in the
enclosure. See Figure 3.
b. When communicating with the outdoors through vertical
ducts, each opening shall have a minimum free area of
one square inch per 4,000 BTU/H of the total input rating of all gas appliances
in the enclosure. See Figure 4.
c. When communicating with the outdoors through horizontal ducts, each
opening shall have a minimum free area of 1 square inch per 2,000 BTU/H of
the total input rating of all gas appliances in the enclosure. See Figure 5.
When ducts are used, they shall be of the same cross-sectional area as the
free area of the openings to which they connect. The minimum short side
dimension of rectangular air ducts shall not be less than 3” (7.62 cm).
Louvers and Grilles
In calculating free area for ventilation and combustion air supply openings,
consideration must be given to the blocking effect of louvers, grilles, or
screens protecting the openings. Screens must not be smaller than ¼” (6.4
mm) mesh. If the free area through a particular design of louver or grille is
known, it should be used in calculating the size of opening required to provide
the free area specified. If the design and free area is not known, it may be
assumed the wood louvers and grilles will allow 20-25% free area and metal
louvers and grilles will allow 60-75% free area. Louvers and grilles must be
installed in the open position or interconnected with the water heater so that
they are opened automatically during water heater operation.
Figure 4 –Communicating with the Outdoors through Vertical Ducts
Figure 5 –Communicating with the Outdoors through Vertical Ducts

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LP-436 REV. 3.21.14
Corrosive Atmospheres
If this water heater is to be installed in a beauty shop, barber shop, photo processing lab, dry cleaning establishment, a building with an
indoor pool, or near a chemical storage area, it is imperative that the combustion and ventilation air be drawn from outside these areas.
These particular environments contain products such as aerosol sprays, detergents, bleaches, cleaning solvents, refrigerants, and
other volatile compounds that, in addition to being highly flammable, become highly corrosive acid compounds when burned. Exposure
to such compounds can be hazardous and lead to premature product failure. Should the water heater fail due to exposure to such a
corrosive atmosphere, the warranty is void.
Venting
When installing the venting system, make sure to follow all local codes, or, in the absence of local codes, National Fuel Gas Code,
ANSI Z223.1/NFPA 54 in the United States, or CAN/CSA B149.1, National Gas and Propane Installation Code in Canada. Never
operate the water heater unless it is properly ventilated to the outdoors and has adequate air supply for proper operation. Failure to
properly install the venting system could result in property damage, personal injury, or death.
High heat sources (sources generating heat 100oF / 37oC or greater, such as stove pipes, space heaters, etc.) may damage plastic
components of the water heater as well as plastic vent pipe materials. Such damages ARE NOT covered by warranty. It is
recommended to keep a minimum clearance of 8” from high heat sources. Observe heat source manufacturer instructions, as well as
local, state, provincial, and national codes, laws, regulations and ordinances when installing this water heater and related components
near high heat sources.
Automatic Flue Damper/Drafthood Assembly
The flue damper/drafthood assembly has been shipped from the factory in a separate box attached to this water heater. Before
installing the flue damper/drafthood assembly, verify that it is the correct model for this water heater (the CG125N73 uses a 5” flue
damper, all other 73 gallon models use a 6” flue damper; CG250N65 uses a 7” flue damper, all other 65 gallon models use an 8” flue
damper). If the wrong assembly has been shipped or is missing completely, immediately contact the dealer where the water heater was
purchased. Never operate this water heater without the manufacturer’s flue damper/drafthood assembly installed.
DO NOT modify the flue damper / drafthood assembly in any way. DO NOT turn on the electrical power to the water heater until the flue
damper / drafthood assembly is installed. Failure to follow these instructions can result in property damage, personal injury, or death.
When installing the water
heater, make sure the
location allows clear
viewing of the flue
damper. When the damper
is in the open position, the
paddle is perpendicular to
the water heater. The flue
damper must be in an
open position when the
water heater’s burners are
operating.
To install the flue damper/drafthood assembly, use the following instructions and secure
all pieces with the provided sheet metal screws. See Figure 6.
1. Remove the flue damper/drafthood assembly from its packaging.
2. Center the assembly over the flue collector outlet.
3. Rotate the assembly so that the wire connector on the water heater can plug into the
flue damper motor connector.
4. Use the wire connector to secure the assembly to the flue connector.
5. Install the flue damper support leg on the assembly.
6. Secure the assembly to the top of the water heater.
7. Plug the wire connector on the water heater into the flue damper motor connector.
Venting System
The venting system must be attached to the drafthood to connect the water heater to the
gas vent or chimney. The vent pipe connecting the water heater must be of the same
size as the drafthood outlet. It is highly recommended to install this water heater on a
Figure 6 –Flue Damper/Drafthood Assembly
Figure 7 –Power Vent Kit Installation

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LP-436 REV. 3.21.14
separate venting system from other appliances. In some installations, proper venting may require the use of a larger diameter vent pipe
and/or combined venting with other appliances. Consult the vent tables in the ANSI Z223.1/NFPA 54 in the United States, of CAN/CSA
B149.1 National Gas and Propane Installation Code, in Canada, to correctly size the vent pipe.
When connecting the vent pipe to the water heater, the following instructions must be followed:
Install the vent pipe in such a way as to avoid any unnecessary bends that could create resistance to the flow of combustion
gases.
The length of the horizontal vent pipe must not exceed 75% of the vertical vent pipe height and never exceed 20’ (6.1 m).
All horizontal runs must have a minimum rise of ¼” (21 mm/m) per foot of run. See Figure 7.
All joints must be securely fastened with sheet metal screws or other approved means.
All single wall vent piping must maintain a minimum of 6” (15.2 cm) of clearance from combustible materials.
Venting systems made with single wall piping cannot pass through any attic, inside wall, crawl space, confined space, or any
floor.
The vent piping must be accessible for inspection, cleaning, and replacement.
Optional Side Wall Power Vent Kits
When using an optional power vent kit, the power venter must be properly secured against the outside wall. Failure to properly secure
the power venter can result in exhaust gas leak, property damage, personal injury, or death.
This water heater is approved for installation with a TjernlundTM side wall power vent kit. See Figure 7. This kit can be installed as part
of a new installation or retrofitted onto an existing installation. The kit consists of a power venter and vent termination assembly. See
Table 2 and Figure 9. Vent piping is not included. Before beginning the installation of the power vent kit, make sure that it is the
appropriate kit for your model water heater. See Table 2. Make sure that the water heater is located so all vent terminal clearances will
be respected. See Figure 8. Maximum equivalent vent pipe length is 50’ for each model. For complete instructions on the side wall vent
kit installation, consult the manual that comes with the kit.

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LP-436 REV. 3.21.14
Figure 8 –Vent Installation Detail
WHEN USING A POWER VENT KIT, THE VENT TERMINATION MUST HAVE:
US Installations1
Canadian Installations2
A) Clearance above grade, veranda, porch, deck, or balcony
12”
30 cm
B) Clearance to window or door that may be opened
3’
1.2 m below or to the side of opening; 30
cm above opening
C) Clearance to permanently closed window
*
*
D) Vertical Clearance to ventilated soffit located above the terminal within a horizontal
distance of 2’ from the center line of the terminal
*
*
E) Clearance to unventilated soffit
*
*
F) Clearance to outside corner
*
*
G) Clearance to inside corner
*
*
H) Clearance to each side of center line extended above meter/regulator assembly
3’
*
I) Clearance to service regulator vent outlet
3’
*
J) Clearance to non-mechanical air supply inlet to building or the combustion air inlet
to any other appliance
3’
1.2 m below or to the side of opening; 30
cm above opening
K) Clearance to a mechanical air supply inlet
6’
91 cm above if within 3 m horizontally
L) Clearance above paved sidewalk or paved driveway located on public property
7’†
2.13 m
M) Clearance under veranda, porch, deck, or balcony
12”‡
*
Table 2 –Power Vent Kit Installation Requirements
1In accordance with current ANSI Z223.1/NFPA 54 National Fuel Gas Code.
2In accordance with the current CAN/CSA B149.1 National Gas and Propane Installation Code.
*Clearance in accordance with local installation codes and the requirements of the gas supplier.
†Vent shall not terminate directly above a sidewalk or paved driveway located between two single family dwellings that serves both dwellings.
‡Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
MODEL
KIT#
MOTOR
DIMENSIONS (INCHES)
VENT HOOD
ROUGH-IN
INLET /
OUTLET
Watts
Amps
A
B
C
D
E
F
G
H
I
J
CG125N73
1
95
1.26
7
7/8
7
11
4
7½(sq)
7
1/8
13(sq)
8
5/8
7 3/8
11
8(sq)
4
CG150N73 to
CG300N65
2
224
1.51
9¼
8½
11½
6
8½(dia)
7
7/8
12(sq)
9½
9½
10
9(dia)
6
Table 3 –Power Venter Including Terminal - NOTES: Max vent length based on total of straight vent pipe plus 11’ for 6” dia. 90oelbow, 7’ for a
4” 90oelbow, 5’ for a 6” 45oelbow, 4’ for a 4” dia. 45oelbow, 4’ for a 8” to 6” reducer, and 5’ for a 6” to 4” reducer.

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LP-436 REV. 3.21.14
Power Venter
Vent Termination
Kit #1
Part # 6060-200
Part # 6060-202
Kit #2
Part # 6060-201
Part # 6060-203
Table 4 –Power Venter and Vent Termination Part Numbers
MODEL
KIT
DRAFT
HOOD
OUTLET
VENT
SIZE
VENT
ADAPTER
VENT
REDUCER
LOCATION
CG125N73
1
5”
4”
5”-4”
1
CG150N73
2
6”
6”
Not Req.
-
CG199N73(X)
2
6”
6”
Not Req.
-
CG250N65
2
7”
6”
7”-6”
1
CG300N65
2
8”
6”
8”-6”
1
Table 5 –Vent Sizing, By Model Number
NOTE: Vent Pipe is Not Included
When the installation is complete, visually inspect the venting system to make sure that all joints are properly connected and all
instructions have been followed. Failure to properly install the venting system can result in property damage, personal injury, or death.
Water Piping
Refer to Figure 10 for a typical installation. Use of this layout should provide a trouble-free installation for the life of the water heater.
Before making the plumbing connections, locate the COLD water inlet and the HOT water outlet. These fittings are both 1 ½” NPT male
thread. Install a shut-off valve close to the water heater in the cold water line. It is recommended that unions be installed in the cold and
hot water lines so that the water heater can be easily disconnected if service is required.
NOTE: It is recommended to use dielectric unions when connecting to the water heater.
When assembling the hot and cold piping, use food grade pipe joint compound and ensure all fittings are tight. It is imperative that open
flame is not applied to the inlet and outlet fittings, as heat will damage or destroy the plastic lined fittings. This will result in premature
failure of the fittings, which is not covered by warranty.
Temperature and Pressure Relief Valve
DO NOT plug the temperature and pressure relief valve or its discharge line. DO NOT remove the relief valve. Make sure the relief
valve is properly sized for the water heater. If the relief valve continuously discharges water, call a qualified service technician to correct
the problem. Failure to follow these instructions can result in property damage, personal injury, or death.
To protect from excessive pressure and/or temperature, the manufacturer has installed a temperature and pressure relief valve that
meets the requirements of the Standard for Relief Valves and Automatic Gas Shut-Off Devices for Hot Water Supply Systems, ANSI
Z21.22 in the United States, and CSA 4.4 in Canada. This relief valve has a maximum set pressure that does not exceed the
hydrostatic working pressure of the water heater (150 psi = 1,035 kPa) and a BTU/H rating equal to or greater than the input rating, as
shown on the water heater rating plate. It should never be plugged or removed from the opening marked for it on the water heater.
If this relief valve should need to be replaced, use only a new temperature and pressure relief valve. Never install an old or existing
relief valve, as it may be damaged or inadequate for the working requirements of the new water heater. This new relief valve must meet
all local codes, or, at minimum, the requirements listed above. Never install any other type of valve between the relief valve and the
water heater.
A discharge line must be installed into the relief valve. The discharge line:
Must not be smaller than the outlet pipe size of the relief valve.
Must not terminate less than 6” (15.2 cm) and not more than 12” (30.5 cm) above a floor drain.
Must not be restricted in any way. Do not thread, cap, or in any way restrict the end of this outlet.
Must be of a material capable of withstanding 193oF (90oC) without distortion.
Must be installed to allow complete drainage of the relief valve and discharge line.
Must terminate at an adequate free-flowing drain.
Figure 9 –Power Venter and Vent Termination

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LP-436 REV. 3.21.14
Pressure Build-Up in a Water System
When the water heater operates, the heated water expands creating a pressure build-up. This is a natural function and is one of the
reasons for installing a temperature and pressure relief valve. If the cold water supply line has a built-in water meter, check valve, or
pressure-reducing valve, a suitable expansion tank must be installed to prevent pressure build-up or water hammer effect. Otherwise,
the warranty is void. See Figure 10. An indication of pressure build-up is frequent relief valve discharge. If the relief valve discharges
water on a continuous basis, it may indicate a malfunction of the relief valve and a qualified service technician must be called to have
the system checked and the problem corrected.
Filling the Water Heater
NEVER operate the water heater unless it is completely full of water. Failure to follow this instruction can result in premature failure of
the water heater. Such failure IS NOT covered by warranty.
Check that all the water piping connections have been made. To fill the water heater:
1. Make sure that the water heater drain valve is closed by turning the knob clockwise.
2. Open the cold water supply manual shut-off valve. This valve must remain open as long as the water heater is in use. NEVER
operate the water heater with the cold water supply manual shut-off valve closed.
3. To make sure the water heater is completely full of water, open hot water faucets to let the air out of the water heater and
plumbing system. Leave the faucets open until a constant flow of water is obtained.
4. Check all of the plumbing connections to make sure there are no leaks.
Gas Connections
DO NOT attempt to use this water heater with any gas other than the type shown on the water heater rating plate. Failure to follow this
instruction can result in property damage, personal injury, or death.
The gas piping must be installed as indicated in Figure 10. For the correct size of piping for this water heater, consult the National Fuel
Gas Code, ANSI Z223.1 / NFPA 54 in the United States, or CAN/CSA B149.1, National Gas and Propane Installation Code in Canada.
Only new piping with cleanly cut threads may be used, together with a suitable sealing compound that is approved for natural and
propane gases. It is mandatory that a readily accessible manual shut-off valve be installed in the gas supply line. The gas supply
manual shut-off valve must be close to the water heater. A drip leg (sediment trap) must be installed in the gas line ahead of the main
gas valve to prevent dirt from entering it. A union must be installed between the main gas valve and the gas supply manual shut-off
valve for easy maintenance of the water heater.
NEVER use an open flame to test for gas leaks. A fire or explosion could occur, resulting in property damage, personal injury, or death.
The water heater and its gas connection must be leak tested before placing the appliance into operation. To leak test the system:
1. Turn on the manual gas shut-off valve near the water heater.
2. Use a soapy water solution to test all connections and fittings for leaks. Bubbles indicate a gas leak.
3. Correct all leaks.
Make sure that the inlet pressure to the water heater does not exceed 14 inches of water column (3.5 kPa) for natural gases.
Pressures in excess of ½ pound per square inch (3.5 kPa) can damage the main gas valve, resulting in a fire or explosion from leaking
gas. For purposes of adjustment, the minimum inlet pressure is indicated on the water heater rating plate.
If any pressure testing of the gas line is undertaken at test pressures in excess of ½ psig (3.5 kPa), the water heater and its gas supply
manual shut-off valve must be disconnected from the gas supply piping system, and the end of the pipe sealed with a female cap. If the
testing is to be undertaken at a test pressure less than ½ psig (3.5 kPa), the gas supply manual shut-off valve must be closed.
NOTE: The input rating of the appliance is based on installation and operation at sea level up to elevations of 2,000 ft. Low NOx models
are certified to operate to 2,000 ft in altitude without adjustment.
High altitude orifices MUST BE installed for water heaters operating above 7,500 feet. Failure to follow this instruction can result in
property damage, personal injury, or death.
Installation Instructions for Water Heaters Approved for Combination Space Heating and Potable Water Heating
When using a water heater for combination space and potable water heating, the instructions provided in this manual and the air-
handling unit must be respected, with particular attention paid to the following:

15
LP-436 REV. 3.21.14
All piping and components that are used in the system must be of a nonferrous type suitable for potable water. This also
applies to any sealant used.
The water heater must not be connected to any system that has been previously used for non-potable water heating. This
includes piping because existing piping may have been treated with chemicals for cleaning or sealing the system in the past.
If this water heater is to be used for space heating, make sure all safety codes are respected. Pay special attention to safety
valve pressure and expansion tanks.
Do not use toxic chemicals to clean the potable water heating system.
Where water temperature in excess of 140oF (60oC) is required for a space heating application, a mixing valve must be
installed in the potable side of the system. This will temper the water and reduce the risk of scalding.
If the incoming water line to the heater is equipped with a check valve, water meter, or pressure-reducing valve, an expansion
tank must be installed in the system. This will prevent weeping from the water heater relief valve and premature failure of the
heater due to expansion of water during the heating cycle.
Before acquisition of a water heater for space heating, it is necessary to have the area of intended use sized by a qualified
technician. This will ensure that an adequate water heating capacity will be available for both heating and potable water
supply, and that the application will meet all local codes and public utility requirements.
Figure 10 –Typical Installation
Wiring
This water heater uses an external electrical source for power. It must be electrically grounded in accordance with all local codes, or, in
the absence of local codes, the latest edition of the National Electrical Code, ANSI/NFPA 70 in the United States, or CAN/CSA C22.1,
Canadian Electrical Code, in Canada. Failure to properly ground the water heater can result in property damage, personal injury, or
death.
Before lighting your water heater, check that all of the wires have been installed correctly. See Figure 12. Inspect local wiring for defects
before installing this product. Verify that all wiring connections are properly secured. If wiring on the product appears “loose” or

16
LP-436 REV. 3.21.14
damaged when received, immediately call HTP, Inc. customer service. If instructed to replace any of the original wiring, use only 18
AWG type or greater wire approved for 221oF (105oC).
If you are installing a side wall power vent kit, use the following instructions to connect the power venter to the water heater. See
Figures 11 and 12.
1. In the electrical box of the water heater, remove the jumper between positions 3 and 4 on the terminal block.
2. Install the wires from the power venter control board to the positions on the terminal block in the electrical box of the water
heater.
If the power venter has been bought through a wholesaler, some settings need to be changed on the control board before putting the
water heater into operation. The voltage needs to be set at 24 Volts. This can be done by moving the red voltage jumper on the 24V
prongs. For detailed instructions on how to adjust the power vent settings, consult the Owner’s
Manual that comes with the Tjernlund Power Venter.
If the power venter has been bought directly from HTP, the settings have been factory adjusted to
match the specifications of the water heater. A label will be affixed on the box stating that it was
factory adjusted to HTP commercial gas water heater specifications.
If the water heater requires servicing, label all wires prior to
disconnecting. Verify all wiring connections before
relighting the water heater. Wiring errors can result in
property damage, personal injury, or death. Damages to
this product due to improper wiring ARE NOT covered
under warranty.
Settings on Power Venter
Voltage: 24 Volts
Pre-purge: 0 sec.
Post-Purge: 2 min.
Figure 11 –Wiring Power Vent Kit Detail

17
LP-436 REV. 3.21.14

18
LP-436 REV. 3.21.14

19
LP-436 REV. 3.21.14
Installation Checklist
Location
Is the water heater located close to the chimney or the gas vent and the main use of hot water?
Is the water heater protected from freezing temperatures?
Has a drain pan been installed and piped to a free-flowing drain?
Is the main gas valve accessible for servicing?
Have clearances from combustible materials been observed?
Combustion and Ventilation Air Supply
Is the area around the water heater clean and properly ventilated?
Is the fresh air supply free of corrosive elements and flammable vapors?
Does the water heater have access to enough fresh combustion air?
Have the fresh air openings been sized correctly and has consideration been given to the blocking effect of louvers and
grilles?
Venting
Has the manufacturer’s supplied flue damper/drafthood assembly been installed correctly?
Is the vent piping made of an approved material and sized correctly?
Have all horizontal runs of vent pipe been installed with a minimum rise of ¼” per foot of run?
Has all vent piping been secured with sheet metal screws?
Water Piping
Has a temperature and pressure relief valve been installed?
Does this valve have a discharge line installed, and is it piped to a free-flowing drain?
Have all the piping connections been properly installed, and are they leak free?
Is the water heater full of water?
Gas Connections
Is the gas supplied to the water heater the same type indicated on the water heater rating plate (Natural)?
Has the gas line been installed with a manual shut-off valve, union, and drip leg?
Is the gas piping large enough and made of an approved material?
Have all connections been made with an approved joint compound?
Has the gas piping been tested for leaks with a soap and water solution?
Wiring
Has the wiring been properly installed?
Have the electrical connections been checked, and are they secure?
Is the water heater electrically grounded?
PART 3 –OPERATING INSTRUCTIONS
Lighting the Water Heater
DO NOT LIGHT this water heater if:
It is not full of water.
The gas supplied does not match the type listed on the rating plate.
The flue damper/drafthood assembly has not been installed.
Gasoline or any other flammable vapors or liquids have been stored in the vicinity of the water heater.
Failure to follow these instructions could result in property damage, serious personal injury, or death.
Before lighting or relighting the water heater, make sure you have read and understood all of the instructions
and warnings in this manual and on the water heater. If you have any questions about lighting the water heater,
immediately contact a qualified installer, service agency, or gas supplier.

20
LP-436 REV. 3.21.14
Drafthood Operation
It is important to check that the ventilation system is working properly once the water
heater main burner has been lit. Wait 10 minutes after lighting the burner. Then
introduce a match or candle around the opening of the drafthood. If the flame is
drawn towards the opening, this indicates proper ventilation. If the flame flutters or is
blown out, combustion gases are escaping from the drafthood opening. If this
occurs, shut the water heater off immediately and locate the problem. Do not try
and operate the water heater again until you are satisfied that the problem has
been corrected.
Water Temperature Regulation
The higher the temperature setting, the greater the risk of scalding. Hot water
can cause third degree burns in 1 second at 160oF (71oC), 5 seconds at 150oF
(65oC), and 30 seconds at 130oF (54oC). In households where there are
children, physically challenged individuals, or elderly persons, mixing valves
for point of use are necessary as a means of reducing the scalding potential of
hot water. Failure to install a mixing valve can result in serious personal injury
or death.
The water temperature for all models is controlled by a thermostat with two sensing
elements. One sensor is located near the top of the tank and the other is near the
center. The thermostat is factory adjusted to its lowest temperature setting. To
adjust the water temperature, insert a small flat head screwdriver into the slotted
screw located in the hole on the front of the thermostat. See Figure 14. Turn the
temperature dial to the desired setting. To maximize the efficiency of the water
heater and reduce the risk of scalding, it is recommended that the dial be adjusted
to the lowest setting that produces an acceptable hot water supply. The dial may be
set from 100oF to 180oF (38oC to 82oC).
When hot water is drawn from the tank in frequent short bursts, a condition known as “stacking” is
created. “Stacking” is the result of increased cycling of the burner and can produce very hot water
temperatures at the hot water outlet. Always remember to check the hot water coming out of any faucet
with your hand before use. This will reduce the risk of scalding related injury.
Should overheating occur or the gas supply fail to shut off, close the gas supply manual shut-off
valve. Failure to follow this instruction can result in serious personal injury or death.
Out of Fuel
If your water heater should run out of gas, proceed as follows:
1. Set the thermostat to the lowest setting.
2. Turn the gas control knob clockwise to “OFF”.
3. Turn off all electric power to the appliance.
4. Once the gas supply has been reestablished, proceed to Lighting Instructions.
PART 4 –GENERAL MAINTENANCE
Housekeeping
DO NOT STORE or use gasoline or other flammable vapors or liquids around the water heater.
DO NOT BLOCK or in any way restrict the flow of fresh air to the water heater.
DO NOT PUT or store any objects on the top of the water heater.
Failure to follow these instructions can result in property damage, personal injury, or death.
Keep the area around the water heater clean and free of dust, lint, and dirt. Vacuum any dirt as
required. Make sure that all of the minimum clearances to combustible materials are being maintained.
Condensation
As moisture from the products of combustion comes in contact with the cold surface of the inner tank, it may condense. This situation
will usually occur:
When the water heater is filled with cold water for the first time.
Figure 14 - Thermostat