GSW 710 User manual

320578-000
REV. 00 (11-04)
710 / 710 ASME
On-Demand Water Heater
Installation Manual and Owner’s Guide
Gas Tankless Water HeaterTM
710 / 710 ASME Models
Suitable for potable water heating and space-heating *
* Please refer to local codes for space-heating compliance.
FEATURING
• ENDLESS HOT WATER
• ON-DEMAND USAGE
• COMPACT, SPACE SAVING
• ENERGY CONSERVATION
• COMPUTERIZED SAFETY
• NO PILOT LIGHT
• EASY-LINK SYSTEM
WARNING
This product must be installed
and serviced by a licensed
plumber, a licensed gas fitter,
or a professional service tech-
nician. Improper installation
and/or operation, or installation
by an unqualified person, will
void the warranty
- Do not store or use gasoline or other flam-
mable 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 electric switch, do not
use any phone in your building.
• Immediately call your gas supplier from a
neighbor's phone. Follow the gas suppli-
er's instructions.
• If you cannot reach your gas supplier, call
the fire department.
- Installation and service must be performed by
a qualified installer, service agency or the gas
supplier.
If the information in these
instructions is not followed
exactly, a fire or explosion may
result causing property dam-
age, personal injury or death.
WARNING
If you have any questions,
please call or write to:
GSW Water Heating
599 Hill Street West
Fergus, ON Canada N1M 2X1
Toll Free: 1-888-479-8324

2
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SAFETY GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . . . . . .3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Included Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Combustion Air Supply
Direct Intake Vent System
Venting Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Exhaust Vent
Vent Termination
Horizontal Installation Diagram
Vertical Installation Diagram
Vent Clearances
Gas Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Gas Supply And Gas Pipe Sizing
Measuring Inlet Gas Pressure
Water Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Pressure Relief Valve
Electrical Connections. . . . . . . . . . . . . . . . . . . . . . . . . 11
Remote Controller Connection . . . . . . . . . . . . . . . . . . 12
Pump Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Pump Control Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 13
A) Recirculation Control: No. 6 ON
B) Storage Tank Circulation Control: No. 7 ON
C) Energy Conserving Recirculation: No. 6 and No. 7
ON
D) Normal Control (Default): No. 6 and No. 7 OFF:
Easy-link System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Easy-Link Connection Procedures
Multi-unit System For Large Volumes. . . . . . . . . . . . . 17
Multi-Unit System Connection Diagram
INITIAL OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Without Remote Controller
With Remote Controller Installed:
TM-RE30 (Optional)
Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Freeze Protection System. . . . . . . . . . . . . . . . . . . . . . 21
Temperature Settings . . . . . . . . . . . . . . . . . . . . . . . . . 21
MAINTENANCE AND SERVICE . . . . . . . . . . . . . . . . . . .22
Unit Draining And Filter Cleaning . . . . . . . . . . . . . . . . 22
GENERAL TROUBLESHOOTING. . . . . . . . . . . . . . . . . .23
Temperature And Amount Of Hot Water . . . . . . . . . . 23
Water Heater. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Remote Controller: TM-RE30 (Optional). . . . . . . . . . . 24
Easy-link System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
TROUBLESHOOTING – ERROR CODES . . . . . . . . . . .24
Single Unit
Easy-Link
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
OPERATING SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . .27
APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Space Heating Applications . . . . . . . . . . . . . . . . . . . . 29
Re-circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Dual-purpose hot water heating
(Domestic and Space Heating). . . . . . . . . . . . . . . . . . 29
Additional Clearances. . . . . . . . . . . . . . . . . . . . . . . . . 30
For sidewall terminations
For rooftop terminations
OPTIONAL ITEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
COMPONENTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . .33
Case assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Computer board assembly . . . . . . . . . . . . . . . . . . . . . 34
Burner assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Water way assembly. . . . . . . . . . . . . . . . . . . . . . . . . . 36
710
710-ASME
PARTS LIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
OUTPUT TEMPERATURE CHART . . . . . . . . . . . . . . . . .40
LIMITED WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Table of Contents

3
INTRODUCTION
Specifications
Model 710
Natural Gas Input
(Operating Range) Min: 24,000 Btu/h Max: 240,000 Btu/h
Propane Input
(Operating Range) Min: 24,000 Btu/h Max: 240,000 Btu/h
Gas Connection 3/4” NPT
Water Connections 3/4” NPT
Water Pressure 15 - 150 psi *
Natural Gas
Inlet Pressure Min. 5.0” WC Max. 10.5” WC
Propane
Inlet Pressure Min. 8.0” WC Max. 14.0” WC
Manifold Pressure Natural: 2.35” WC
Propane: 3.55” WC
Weight 25.4Kg (56 lbs.)
Dimensions H 600mm (23.6 in.) × W 470mm (18.5 in.) ×
D 226mm (8.9 in.)
Ignition Electric Ignition
Electric
Supply 120 VAC / 60 Hz
Consumption
Operation 112 W (0.93 A)
Standby 8.9 W (0.07 A)
Freeze-
Protection 187 W (1.56 A)
*40 psi or above is recommended for maximum flow
NOTE
• All references to the 710 also refer to the 710
ASME model
• Check the rating plate to ensure this product
matches your specifications.
The manufacturer reserves the right to discontinue, or
change at any time, specifications or designs without
notice and without incurring obligations.
• This manual provides information necessary for the
installation, operation, and maintenance of the water
heater water heater.
• The model description is listed on the rating plate which
is attached to the front cover of the water heater.
• Please read all installation instructions completely before
installing this product.
• If you have any problems or questions regarding this
equipment, consult with the manufacturer or its local rep-
resentative.
• Please read all installation instructions completely before
installing this product.
• The710isanon-demand,tanklesswaterheaterdesigned
to efficiently supply endless hot water for your needs.
• The principle behind the 710 Water Heater is simple:
Exhaust
Computer
Board
Thermistor
Water Control
Valve
Thermistor
Heat
Exchanger
Burner
Fan
Thermistor
Gas
Valve
Gas
Line
Hot Water
Outlet Cold Water
Inlet
Flow Sensor
*This diagram illustrates tankless water heater design con-
cepts only and is not accurate to the 710’s physical descrip-
tion.
A hot water tap is turned on.
Water enters the heater.
The water flow sensor detects the water flow.
The computer automatically ignites the burner.
Water circulates through the heat exchanger and then
gets hot.
The computer will modulate the gas supply valve and
water flow to produce the right amount of hot water at the
correct temperature.
When the tap is turned off, the unit shuts down.
SAFETY GUIDELINES
PLEASEREADTHIS MANUALCAREFULLYAND FOLLOW
ALL DIRECTIONS.
WARNING
Installation and service must be per-
formed by a qualified installer (for exam-
ple, a licensed plumber or gas fitter),
otherwise the warranty by the manufac-
turer will be void.
The installer (licensed professional) is
responsible for the correct installation
of your water heater and for compliance
with all national, provincial, and local
codes.
•
•
General
1. Follow all local codes, or in the absence of local codes,
follow the most recent edition of CSA B149.1 Natural
Gas and Propane Installation Code.
2. Properly ground the unit in accordance with all local
codes or in the absence of local codes, with CSA stan-
dard C22.1 Canada Electrical Code Part 1.
1.
2.
3.
4.
5.
6.
7.

4
3. Carefully plan where you intend to install your 710
Water Heater. Please ensure:
• Your water heater will have enough combustible air
and proper ventilation.
• Locate your heater where water leakage will not
damage surrounding areas (please refer to pg. 4).
4. Check the rating plate for the correct GAS TYPE,
GAS PRESSURE, WATER PRESSURE and ELECTRIC
RATING. If this unit does not match your requirements,
do not install and consult with the manufacturer.
5. If any problem should occur, turn off all hot water taps
and turn off the gas. Then call a trained technician or the
Gas Company or the manufacturer.
INSTALLATION
All gas water heaters require careful and correct installation
to ensure safe and efficient operation. This manual must be
followed exactly. Read the “Safety Guidelines” section at the
beginning of this manual.
CAUTION
The warranty will not cover damage
caused by water quality. Water hard-
ness that leads to scale formation and/or
corrosion may affect/damage the water
heater. Hard water scaling and/or cor-
rosion must be avoided or controlled by
proper water treatment.
The manufacturer recommends using
the direct-vent kit, when the water heater
is installed in a beauty salon. Some
chemicals used in a beauty salon may
affect the flame sensor. Water heater
may not work properly.
Although the 710 is designed to operate
with minimal sound, the manufacturer
does not recommend installing the unit
on a wall adjacent to a bedroom, or a
room that is intended for quiet study or
meditation, etc.
Locate your heater close to a drain
where water leakage will not do damage
to surrounding areas. As with any water
heating appliance, the potential for leak-
age at some time in the life of the prod-
uct does exist. The manufacturer will not
be responsible for any water damage
that may occur. If you install a drain pan
under the unit, ensure that it will not
restrict the combustion air flow.
•
•
•
•

5
GENERAL
The manifold gas pressure is preset at the factory. It is
computer controlled and should not need adjustment.
Maintain proper space for servicing. Install the unit so
that it can be connected or removed easily. Refer to pg.
5 and pg. 6 for proper clearances.
The electrical connection requires a means of disconnec-
tion, to terminate power to the water heater for servicing
and safety purposes.
If you will be installing the unit in a contaminated area
with a high level of dust, sand, flour, aerosols or other
contaminants/chemicals, they can become airborne and
enter and build up within the fan and burner caus-
ing damage to the unit. In those environments (e.g.
residential or commercial laundry facilities, hair salons,
pet salons, chemical plants etc.), please purchase the
optional direct-vent conversion kit and convert the 710 to
a sealed combustion unit. Direct venting allows the 710
to draw fresh intake air from the outside. The warranty
will not cover damage caused to the unit due to instal-
lation in a contaminated environment that has not been
converted using the direct-vent conversion kit.
Particles from flour, aerosols, and other contaminants
may clog the air vent or reduce the functions of the rotat-
ing fan and cause improper burning of the gas. Regularly
ensure that the area around the unit is dust- or debris-
free; regular maintenance is recommended for these
types of environment.
Do not install the unit where the exhaust vent is pointing
into any opening in a building or where the noise may
disturb your neighbors. Make sure the vent termination
meets the required distance by local code from any
doorway or opening to prevent exhaust from entering a
building (refer to pg. 9).
Included Accessories
Check that the installation manual, the communication
cable, and the product registration card are included with
the unit. Items
Manual Qty: 1
Communication Cable (Gray) Qty: 1
Product Registration Card Qty: 1
1.
2.
3.
4.
5.
6.
WARNING FOR INSTALLATION
LOCATIONS
Do not install the heater
where water, debris or flam-
mable vapors may get into
the flue terminal. This may
cause damage to the heater
and void the warranty.
Do not have the vent ter-
minal pointing toward any
opening into a building. Do
not locate your heater in a
pit or location where gas
and water can accumulate.
Do not install next to a dryer
or any source of airborne
debris that can be trapped
inside the combustion
chamber, unless the system
is direct vented.
Do not install the water heat-
er vent terminator within 3 ft.
of any air intake or building
opening (refer to pg. 9).
Installation
Follow all local codes, or in the absence of local codes,
follow the most recent edition of CSA B149.1 Natural
Gas and Propane Installation Code.
When installed, the 710 water heater shall be located in
an area to maintain the following minimum clearances
around the unit:
Maintain Clearances.
1.
2.

6
Bottom 305mm
(12 in.)
Back
25mm
(1 in.)
Front 76mm (4 in.)
(610mm (24 in.)
recommended for service)
Top
305mm (12 in.)
Side
(50mm
(2 in.)
Side
(50mm (2 in.)
Combustion Air Supply
The water heater location must provide enough air for
proper combustion and ventilation of the surrounding area.
See the latest edition of B149.1 or any applicable local
codes. In general, these requirements specify that if the unit
is installed in a confined space, there must be a permanent
air supply opening.
Minimum recommended air supply opening size for water
heater:
Water
heater
size
When drawing
make-up air from
outside the
building
When drawing make-
up air from inside the
building (from other
rooms within)
MAX
240,000
BTU/h
103cm2(16.0 in2) 1548cm2(240 in2)
When combustion
air is supplied from
outside the building,
an opening commu-
nicating directly with
the outside should
have a minimum
free area of 6.5cm2
(1 in2) per 15,000
BTUH input of the
total input rating of
water heater in the
enclosed area.
When combustion air
is supplied from inside
the building, an open-
ing communicating with
the rest of the dwelling
should have a minimum
free area 6.5cm2(1 in2)
per 1,000 BTUH input
of the total input rat-
ing of water heater in
the enclosed area. This
opening should never be
less than 1284cm2(199
in2).
Combustible Air Supplied by Mechanical fan or Make up air
device
The 710 water heater is equipped with a combustible air
sensor that will shut off the unit when inadequate combus-
tible air supply to unit is detected.
• If a mechanical fan or make up air device is used to
supply air to the water heater or utility room, the installer
should make sure it does not create drafts which could
cause nuisance shutdowns.
• If a blower is necessary to provide adequate combustion
air to the water heater, the blower and water heater must
be set up so that the water heater cannot fire unless the
blower is operating. Possible methods include the use of
external flow sensors/transmitters and relays.
Direct Intake Vent System
This 710 water heater may be converted to a direct-vent
(sealed combustion) appliance by installing an adapter (Part
No. TM-DV32) which will bring all required combustible air
from outside the building. When installing the direct-vent
conversion kit, please follow all instructions included with
the kit.
• The 710 must be installed in a location where the proper
amount of combustible air will be available to it at all
times without obstructions.
• If used as a direct-vent appliance, the 710 requires a
102mm (4 in.) combustible air supply pipe. The intake
pipe must be sealed airtight.
• Air supply pipe can be made of ABS, PVC, galvanized
steel, corrugated aluminum, corrugated stainless steel or
Category III stainless steel.
• Change the DIPswitch settings to the direct-vent system.
(See diagram below)
• Sidewall venting is recommended for the direct-vent sys-
tem.
• The manufacturer recommends running the exhaust vent
and the intake pipe parallel.
• The Direct-Vent Conversion Kit has an “INLET” mark
as shown below. Do not reverse the INLET and the
EXHAUST connections when installing vent pipes.
Make sure power to the unit is turned OFF
before changing the DIPswitch settings.
1
2
3
4
5
6
7
8
TMP1
ON
TMP2
TMP3
MODE
DIRE
OUT
D-PRT
MST
The dark square
is the direction the
DIPswitch should
be set to.
Left bank of
DIPswitches
Left Bank of
DIPswitches
7-Seg LED
Right bank of
DIPswitches
Direct-Vent Conversion Kit

7
Direct vent
conversion kit
Inlet Exhaust
Venting Connections
WARNING
Improper venting of this appliance can
result in excessive levels of carbon mon-
oxide which can result in severe personal
injury or death.
This water heater must be vented in accordance with
the section “Venting of Equipment" of the latest edition
of Section 7 of CSA B149.1 Natural Gas and Propane
Installation Code and all applicable local building codes.
Exhaust Vent
This is a Category III appliance and must be vented accord-
ingly. The vent system must be sealed air tight. All seams
and joints without gaskets must be sealed with high heat
resistant silicone sealant or UL listed aluminum adhe-
sive tape having a minimum temperature rating of 177°C
(350ºF). For best results, a vent system should be as short
and straight as possible.
1. This water heater is a Category III appliance and must be
vented accordingly with any 102mm (4 in.) vent approved
for use with Category III or Special BH type gas vent.
2. The manufacturer recommends the “T-Vent” line
manufactured by TAKAGI (Refer to the venting bro-
chure for details). However, the following are also UL
listed manufacturers: ProTech Systems Inc. (FasNSeal),
Flex-L Inc., Z-Flex Inc. (Z-Vent III), Metal-Fab Inc., and
Heat-Fab Inc. (Saf-T Vent).
3. Follow the vent pipe manufacturer’s instructions
when installing the vent pipe.
4. Do not common vent this appliance with any other
vented appliance (Do not terminate vent into a chimney.
If the vent must go through the chimney, the vent must
run all the way through the chimney with Category III
approved or Special BH vent pipe).
5. Themaximumlengthofexhaustventpipingmustnotexceed
15.24m (50 ft.) deducting 1.5m (5 ft.) for each elbow used
in the venting system. Do not use more than 5 elbows.
*For each elbow added, deduct 1.5m (5 ft.) from max.
vent length.
No. of Elbows Max. Vertical or Horizontal Length
0 15.24m (50 ft.)
1 13.7m (45 ft.)
2 12.2m (40 ft.)
5 7.6m (25 ft.)
6. When the horizontal vent run exceeds 1.5m (5 ft.), sup-
port the vent run at 915m (3 ft.) intervals with overhead
hangers.
7. The manufacturer will not be responsible for any damage
to the water heater caused by condensation from the
vent. For vent runs longer than 1.5m (5 ft.), installation of
a condensate drain is recommended. Install the conden-
sate drain as close to the water heater as possible. For
horizontal runs, slope the vent run back toward the water
heater where the condensate drain is installed at a rate of
6.4mm (1/4 in.) per 305mm (1 ft.). Refer to pg. 8 for the
diagrams. When installing the vent system, all appli-
cable national and local codes must be
followed. If you install thimbles, fire stops
or other protective devices and they pen-
etrate any combustible or noncombustible
construction, be sure to follow all appli-
cable national and local codes.
Vent Termination
WARNING
Improper installation can cause nausea or
asphyxiation, severe injury or death from
carbon monoxide and flue gases poison-
ing. Improper installation will void product
warranty.
• The vent terminator provides a means of installing vent
pipe through the building wall and must be located
in accordance with CSA-B149.1 and applicable local
codes.
• A proper sidewall vent terminator is recommended when
the water heater is vented through a sidewall. If the 710
is converted to a direct-vent unit, a proper sidewall direc-
tvent terminator, such as a concentric style terminator, is
to be used.

8
General rules for venting the 710 water heater are:
Place the water heater as close as possible to the vent
terminator.
The vent collar of the water heater must be fastened
directly to an unobstructed vent pipe.
Do not weld the vent pipe to the water heater collar.
Do not cut the vent collar of the unit.
The weight of the vent stack must not rest on the water
heater.
The vent must be easily removable from the top of the
water heater for normal service and inspection of the
unit.
The water heater vent must not be connected to any
other gas appliance or vent stack.
Avoid locating the water heater vent terminator near any
air intake devices. These fans can pick up the exhaust
flue products from the gas appliance and return them to
the building. This can create a health hazard.
Avoid using an oversized vent pipe or using extremely
long runs of the pipe.
Locate the vent terminator so that it cannot be blocked by
any debris, at any time. Most codes require that the ter-
minator be at least 305mm (12 in.) above grade, but the
installer may determine if it should be higher depending
on the job site condition and applicable codes.
For rooftop venting, a rain cap must be installed.
THE MANUFACTURER recommends the “T-Vent”
line manufactured by TAKAGI (Refer to the venting
brochure for details). However, the following are
also UL listed manufacturers: ProTech Systems Inc.
(FasNSeal), Flex-L Inc., Z-Flex Inc. (Z-Vent III), Metal-
Fab Inc., and Heat-Fab Inc. (Saf-T Vent).
Horizontal Installation Diagram
Vertical Condensation
Drain (Install accord-
ing to local codes)
Sidewall Vent
Terminator
Wall
Backflow
preventor
(Recommended
for freezing
weather condi-
tions: 2.2°C
(36°F) and below)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Vertical Installation Diagram
Vertical Condensation
Drain (Install accord-
ing to local codes)
Backflow
preventor
(Recommended
for freezing
weather condi-
tions: 2.2°C
(36°F) and below)
Roof Rain Cap
Roof Flashing
• Regarding the clearance from the terminator to the air
inlet or opening, refer to the next page.
• Install a condensation drain in the venting.
• Follow the vent system to vent manufacturer’s instruction
and local code.
• Do not common vent or connect any vent from other
appliances to the 710 vent.
• Use 102mm (4 in.) category III approved or Special BH,
single or double wall stainless steel vent pipe.

9
Vent Clearances
Canada
Direct vent and other than Direct Vent
A Clearance above grade, veranda, porch, deck, or balcony. 1 foot 30.5cm
B Clearance to window or door that may be opened 3 feet 91.5cm
C Clearance to permanently closed window *
DVertical clearance to ventilated soffit located above the vent termi- nator within a horizontal distance of 2 feet (61cm) from the center
line of the terminator. *
E Clearance to unventilated soffit *
F Clearance to outside corner *
G Clearance to inside corner *
HClearance to each side of center line extended above meter/regula-
tor assembly 3 feet 91.5cm
I Clearance to service regulator vent outlet. 3 feet 91.5cm
JClearance to non-mechanical air supply inlet to building or the com-
bustion air inlet to any other application 3 feet 91.5cm
K Clearance to mechanical air supply inlet. 6 feet 1.8m
LClearance above paved sidewalk or paved driveway
located on public property. 7 feet 2.1m
M Clearance under veranda, porch deck, or balcony. 1 foot 30.5cm
* For clearances not specified in CSA-B149.1, please use clearances in accordance with local installation codes and
the requirement of the gas supplier.

10
Gas Connections
Gas Supply And Gas Pipe Sizing
Turn off all electric power to the water heater if service
is to be performed.
Turn the manual gas valve located on the outside of
the unit clockwise to the off position.
1.
2.
TO TURN OFF GAS TO
APPLIANCE
WARNING
Conversion of this unit from natural gas
to propane or vise versa will void all war-
ranty. Contact your local distributor to get
the correct unit for your gas type. The
manufacturer is not liable for any property
and/or personal damage resulting from gas
conversions.
*Check that the type of gas matches the rating plate
first.
1. The minimum and maximum inlet gas pressures are:
Gas type Inlet gas pressure
Natural Gas Min.: 5.0" WC – Max.: 10.5" WC
Propane Gas Min.: 8.0" WC – Max.: 14.0" WC
2. Gas pressure below this specified range for the 710
and/or insufficient gas volume will adversely affect per-
formance. These pressures are measured when the 710
is in full operation.
3. Inlet gas pressure must not exceed the above maximum
values; gas pressure above the specified range will
cause dangerous operating conditions and damage to
the unit. Ensure that any and all gas regulators used
are operating properly and are providing gas pressures
within the specified range shown above.
4. Until testing of the main gas line supply pressure is com-
pleted, ensure the gas line to the 710 is disconnected to
avoid any damage to the water heater.
Measuring Inlet Gas Pressure
The 710 cannot perform properly without sufficient inlet
gas pressure. Below are instructions on how to check the
inlet gas pressure. THIS IS ONLY TO BE DONE BY A
LICENSED PROFESSIONAL.
1. Shut off the manual gas valve on the supply gas line.
2. Open a faucet. The unit should turn on and the gas in the
gas pipe line should purge. Leave the faucet on to keep
the unit running until the unit shut down due to lack of gas
supply. Then shut the faucet off.
3. Remove the screw for the pressure port located on the
gas inlet of the 710 shown in the diagram to the right.
4. Connect the manometer to the pressure port.
5. Re-open the manual gas valve. Check to see that there
are no gas leaks.
6. Open some of the fixtures that use the highest flow rate
to turn on the 710.
7. Check the inlet gas pressure. When 710 is on a maxi-
mum burn, the manometer should read from 5.0” to 10.5”
WC for Natural gas, from 8.0” to 14.0” WC for Liquid
Propane. Size the gas pipe appropriately to supply
the necessary volume of gas required for
the 710 models (240,000 BTU/h for both
Natural Gas and Liquid Propane) using
CSA B149.1 or local codes. Otherwise, flow
capabilities and output temperatures will be
limited.
Install a manual gas shut-off valve between the 710 and
the gas supply line.
When the gas connections are completed, it is necessary
to perform a gas leak test either by applying soapy water
to all gas fittings and observing for bubbles or by using a
gas leak detection device.
Always purge the gas line of any debris and/or water
before connecting to the gas inlet.
1.
2.
3.

11
Water Connections
Do not use this water heater if any part has been sub-
mersed under water. Immediately call a licensed profes-
sional to inspect the water heater and to replace any
damaged parts.
FOR YOUR SAFETY, READ
BEFORE OPERATING
All pipes, pipe fittings, valves and other components,
including soldering materials, must be suitable for pota-
ble water systems.
A manual shut off valve must be installed on the cold
water inlet to the water heater between the main water
supply line and the 710.
In addition, a manual shut off valve is also recommended
on the hot water outlet of the unit. If the 710 is installed
within, or subjected to, a closed loop water system, a
thermal expansion tank must be installed.
Before installing the water heater, flush the water line
to remove all debris, and after installation is com-
plete, purge the air from the line. Failure to do so may
cause damage to the heater.
There is a wire mesh filter within the cold inlet to trap
debris from entering your heater. This will need to be
cleaned periodically to maintain optimum flow.
CAUTION
Do not reverse the hot outlet and cold inlet
connections to the 710 Water Heater. This
will not activate the water heater.
Pressure Relief Valve
The 710 has a high-temperature shut-off switch built in as a
standard safety feature (called a Hi-Limit switch) therefore a
“pressure only” relief valve is required.
This unit does not come with an approved pressure relief
valve.
An approved pressure relief valve must be installed on
the hot water outlet.
The pressure relief valve must conform to ANSI Z21.22
or CAN 1-4.4 and installation must follow local code.
The discharge capacity must be at least 240,000 BTU/
h.
1.
2.
3.
4.
5.
1.
2.
3.
4.
The pressure relief valve needs to be rated for a maxi-
mum of 150 psi.
The discharge piping for the pressure relief valve must
be directed so that the hot water cannot splash on any-
one or on nearby equipment.
Attach the discharge tube to the pressure relief valve and
run the end of the tube to within 6" from the floor. This
discharge tube must allow free and complete drainage
without any restrictions.
If the pressure relief valve installed on the 710 discharg-
es periodically, this may be due to a defective thermal
expansion tank or defective pressure relief valve.
The pressure relief valve must be manually operated
periodically to check for correct operation.
For the ASME model, the pressure relief valve must con-
form to and be installed in accordance with ASME code.
As close as
possible
Pressure
Relief
Valve
Hot outlet
Cold inlet
Gas
Electrical Connections
WARNING
Follow the electrical code requirements of
the local authority having jurisdiction. In
the absence of such requirements, follow
the latest edition of CSA C22.1 Canadian
Electrical Code, Part 1.
CAUTION
When servicing or replacing parts within the
710, label all wires prior to disconnection to
facilitate an easy and error free reconnec-
tion. Wiring errors can cause improper and
dangerous operation. Verify proper opera-
tion after servicing.
The heater must be electrically grounded. Do not attach
the ground wire to either the gas or the water piping.
The 710 water heater requires 120 VAC / 60 Hz
electrical power supply that is properly grounded.
• A proper disconnect (i.e. on/off switch, power plug,
etc.) controlling the main power to the 710 must be pro-
vided for service reasons. (Must comply with local codes).
• Connect the power supply to the 710 exactly as
shown in the wiring diagram;
5.
6.
7.
8.
9.
1.
2.

12
A green screw is provided in the junction box to ground
the connection.
Can be hardwired or wired to a plug-in.
The use of a surge protector is recommended in order to
protect the unit from power surges.
Connect Power supply
AC120V 60Hz
Ground
Remote Controller Connection
Disconnect power supply from the water heater.
Take off the water heater’s front cover.
Please find the remote control terminal using the picture
below (located around the lower right-hand side of the
water heater).
Open the plastic cover of the remote controller accessory,
and then attach the fork terminal to the connector base
of the backside the remote controller accessory with two
screws. Make sure the terminals are firmly fixed.
Put the remote wires through the hole on the bottom of
the unit casing.
Connect the remote wires to the remote controller termi-
nal properly. (No polarity) *Do NOT jump or short-cir-
cuit wires. Computer will be damaged.
Replace Front Cover securely.
Wires used for the remote controller connection must
be:
• Minimum 18AWG wire (No polarity)
• Maximum 122m (400 ft.) long
*Fordetails on the connection to the remote controller acces-
sory, refer to the remote controller Installation Manual.
3.
4.
5.
1.
2.
3.
4.
5.
6.
7.
8.
Remote controller terminal
inside water heater
Front of remote
Connect to
these terminals
Back of remote
Connect other end
to these terminals
Pump Connection
The 710 can be used to control a recirculation pump.
Proper pump control helps to preserve the life of the system
and saves energy as well. The water heater pump control
port is a “normally-open” dry contact, and therefore needs
additional components to properly control a recirculation
pump. To control a recirculation pump, connect the pump
to the pump connector in the 710 as shown in the diagram
below. (In a multi-unit system, connect the pump ONLY to
the “PARENT” unit.) The pump is to be connected using
suitable relays shown in the diagram below. Please make
sure the relays are properly rated for the recirculation
pump.
Using the 710 internal thermistors as a temperature control,
the recirculation pump will only turn on when recirculation
is needed.
CAUTION
In a multi-unit system, the pump must be
connected to the "Pump terminal" in the
"PARENT" unit only. If the pump is con-
nected to any of the "CHILD" units, the
pump will not work.
Connect to this
“Pump” connector. Power supply
for relay
Power supply for
pump 120 VAC
220 VAC etc
120 VAC
220 VAC etc
for relay
Thermal
relay
Recirculation
pump
These components are not included with
water heaters and are external to the
unit. They must be acquired separately.

13
Pump Control Mode
The 710 provides the four types of the pump control
modes. The pump control modes are selected by chang-
ing DIPswitch settings. The DIPswitches are located in the
right bank of DIPswitches in the upper-left quadrant of the
computer board in the 710 (see the next column).
DIPswitch settings for the Pump control mode
Pump Control Modes
A)
Recirculation
Control
B) Storage
Tank
Circulation
Control
C) Energy
Conserving
Recirculation
D) Normal
Control
(Default)
8
7
6
5
4
3
2
1
ON
8
7
6
5
4
3
2
1
ON
8
7
6
5
4
3
2
1
ON
8
7
6
5
4
3
2
1
ON
The dark squares indicate the direction the DIPswitches
should be set to.
A) Recirculation Control: No. 6 ON
Feature: Water heaters can provide hot water as soon as
possible like a recirculation usage.
Function: The pump is set only to run when the tempera-
ture of the water in the re-circulation loop is much
lower than the set temperature of the 710. The
pump will run for about 1 minute in every 30 min-
utes to determine whether the water temperature
in the whole recirculation loop is lower than 5C°
(9F°) from the set temperature or not. If the water
temperature is lower than 5C° (9F°) from the set
temperature, the pump will remain running until
the water in the loop reach the set temperature.
Otherwise, the pump will stop for another 30
minutes. If the inlet thermistor of water heaters
detects that the water temperature is lower than
5C° (9F°) from the set temperature before those
30 minutes have elapsed, the pump will activate
immediately and remain running until the water in
the loop reach the set temperature.
Note: The recirculation pump needs to be connected to
the pump terminal of the 710.
Right bank of
DIPswitches
B) Storage Tank Circulation Control: No. 7 ON
Feature: This is to ensure a higher rate of recovery for
storage tank applications.
Function: The 710 makes Water heaters heat the water
3C° (5.4F°) higher than its set temperature. The
circulation pump (from storage tank to Water
heaters) will always remain on. After hot water
temperature reach the temperature above, the
710 makes the Water heaters to adjust the water
flow to be less than 9.8 l/min (2.6 GPM (US)), in
order to detect temperature in the system.
Note: In this mode, the 710 will not provide the pump
control. The termination of the pump is kept ON
position continually.
C) Energy Conserving Recirculation: No. 6 and
No. 7 ON
Feature: Save Energy Mode in Recirculation Control
by keeping the water temperature in the loop
system hot during circulation with Recirculation
Control and Pump Control, so it will cut down the
cost of the gas and electricity.
Function: Energy Conserving Recirculation and the Pump
Control is similar to the “Recirculation Control”
explained above. The hot water temperature in
the loop during recirculation is kept at maximum
50°C (122°F) even if the set temperature of 710
is 55°C (130°F) or above.
Note: The recirculation pump needs to be connected to
the pump terminal of the 710.
D) Normal Control (Default): No. 6 and No. 7
OFF:
Feature: This mode provides no special pump control. The
pump operation can only be turned ON and OFF
by the remote controller.
Function: If a pump is connected to the pump control termi-
nal and both No. 6 and No. 7 are OFF, the pump
will be made to run all the time as long as there
is a power supply to the 710. The pump will stop
when the remote controller is turned off. Water in
the loop will be maintained at set temperature.

14
Easy-link System
The 710 can be connected with other heaters of the same
model with communication cables to work as a multiple
manifold system.
• The Easy-Link system can connect up to 4 units.
• A communication cable (gray color) comes with each
unit. The cables use 18 gauge wire and can be up to
76.2m (250 ft.) long all together.
You can manifold from 2 units to 4 units without a multi-sys-
tem controller. A 4-unit system has full automatic modulation
between 24,000 BTU/h and 960,000 BTU/h.
Gas
Cold
Hot
CAUTION
The Easy-Link system is limited to 4
units. If you connect more than 4 units,
the first 4 units will work as part of the
Easy-Link system, but the other addi-
tional units will only work as individual
units.
The 710 cannot be linked with other
different tankless models in the Easy-
Link system.
•
•
7-Seg LED
Left bank of
DIPswitches
Right bank of
DIPswitches
Do not touch the
Multi-System
connectors.
Easy-Link
connectors
are on each
unit’s com-
puter board.
To change the DIPswitch settings for the Easy-Link system, locate the left bank of
DIPswitches below the 7-seg LED. Do not adjust the right bank of DIPswitches.
Easy-Link Connection Procedures
1. Choose one of your units as the “PARENT” unit.
2. “The PARENT”: Locate the left bank of DIPswitches
to the lower of the 7-seg. LED on the computer board
of the 710 that you select to be the “PARENT” unit.
Change DIPswitch No. 8 to “ON”. Do not change any of
the DIPswitches on the “CHILD” units.
3. Between the “PARENT” and the “CHILD-1”: Connect
the “PARENT connector” of the “PARENT unit” to the “[1]
connector” of the “CHILD-1” unit.
4. Between the “CHILD-1” and the “CHILD-2”: Connect
the “[2] connector” of the “CHILD-1” unit to the “[1] con-
nector” of the "CHILD-2” unit.
5. Between the “CHILD-2” and the “CHILD-3”: Connect
the “[2] connector” of the “CHILD-2” unit to the “[1] con-
nector” of the “CHILD-3” unit.
6. Make sure the “7-seg LED” of all the units’ computer
boards display the unit #. The numbering system of
the 710 automatically allocates the unit # to each water
heater that is part of the Easy-Link system.
PARENT unit Unit #: 1
CHILD units Unit #: 2, 3 and 4
The dark squares indicate the direction the DIPswitches
should be set to.

15
CAUTION
Unless you change DIPswitch No. 8 of the
“PARENT” unit to “ON”, the system will not
work as an Easy-Link system. The units will
work as individual units.
Prohibited
Wrong DIPswitch setting on the “PARENT"
unit
CAUTION
If you connect the “[1] (or [2]) connector”
of the “PARENT” unit to the “PARENT"
(or [1]) connector of the “CHILD-1” unit,
the system will not work as the Easy-Link
system. The units will operate as individual
units.
Prohibited
Wrong connection between the “PARENT”
unit and the “CHILD-1” unit

16
• If a remote controller (optional) is used, it has to be con-
nected to the “PARENT” unit. If the remote controller
is connected to a “CHILD” unit, it will only control that
particular individual “CHILD” unit and will not control the
Easy-Link system as a whole.
Prohibited
Wrong connection between the “CHILD”
unit and the remote controller
The remote controller is not required for
the Easy-Link system.
If running the Easy-Link system with-
out the remote controller, please make
sure the DIPswitch settings for the tem-
perature and direct-vent settings on ALL
the units are set to the same settings.
Otherwise, the units may not operate
properly.
If the remote controller is used, the tem-
perature on all the units in the system
will automatically be set to the same
temperature that is set on the remote.
However, even with the remote, the
direct-vent DIPswitch settings still need
to be set to the same settings on all the
units.
•
•
•
CAUTION
If you connect the “PARENT connector”of
the “PARENT” unit to the “[3] connector”
of the “CHILD-1” unit, the “PARENT” unit
and the “CHILD-1” unit will display “761”
error code.
Prohibited
Wrong connection between the “PARENT”
unit and the “CHILD-1” unit
CAUTION
If you connect the “[2] connector”of the
“CHILD-1” unit to the “[3] connector” of the
“CHILD-2” unit, the “PARENT” unit and
the “CHILD-2” unit will display “761” error
code.
Prohibited
Wrong connection between the “CHILD-1”
unit and the “CHILD-2” unit
CAUTION
If you connect the “PARENT” connector of
the “CHILD-1” unit to the "[1]" connector of
the “CHILD-2” unit, the “CHILD-2” unit will
work as an individual unit, and will not be
part of the Easy-Link system.
Prohibited
Wrong connection between the “CHILD-1”
unit and the “CHILD-2” unit
WARNING
Connecting two “PARENT" connectors
together from two separate units may dam-
age the computer board. The communi-
cation cable has a female end and a male
end so it’s impossible to have a PARENT-
to-PARENT connection with the commu-
nication cable. Do not splice or modify
connectors.

17
Multi-unit System For Large Volumes
Multiple 710 models can be combined for a Multi-Unit sys-
tem, along with the Multiple Unit Controller and Remote
Controller (Parts TM-MC01 and TM-RE30). Each set of con-
trollers (one TM-MC01 and one TM-RE30) can control from
2 units to 20 units for commercial or residential applications.
For a 20-unit system, the computer can modulate between
the usages of 24,000 BTU/h to 4.8 Million BTU/h.
710
TM-MC01
Cold In Hot Out
An individual cut-off switch if hard-wired is recommended
for each unit in a multi-unit system for the purpose of main-
tenance.
Unit 1
TM-RE30
TM-MC01
The dark squares indicate the direction
the DIPswitches should be set to.
Unit 3Unit 2
Multi-Unit System Connection Diagram
Multi-Unit Controller (TM-MC01) and Temperature Remote
Controller (TM-RE30) wiring:
This is the connection diagram between 710 and TM-MC01
for 2 to 20 water heaters. As shown is a sample for 3 water
heaters.
Make sure the “7-seg LED” of all the units’ computer boards
display the unit #. The Multi-unit controller automatically
allocates the unit # (1-20) to each water heater that is part
of the Multi-unit system.

18
In a Multi-Unit system, connect the “[3] connector” and the
“[4] connector” with the communication cable.
Wire [3] (Male Adapter) and
[4] (Female Adapter)
The Comunication Cables are
included with the 710. The
Cables use 18 gauge wire
and can be up to 76.2m
(250 ft.) long.
Please refer to the Multi-unit Controller manual for further
instructions of the Multi-Unit system.
7-Seg LED
Left bank of
DIPswitches
Right bank of
DIPswitches
Multi-unit con-
nectors are on
each unit’s com-
puter board.
Do not touch
the Easy Link
connectors.

19
INITIAL OPERATION
FOR YOUR SAFETY, READ
BEFORE OPERATING
Check the GAS and WATER CONNECTIONS for leaks
before firing unit for the first time.
Open the main gas supply valve to the unit using only
your hand to avoid any spark. Never use tools. If the
knob will not turn by hand, do not try to force it; call a
qualified service technician. Forced repair may result in
a fire or explosion due to gas leaks.
Be sure to check next to the bottom of the unit because
some gases are heavier than air and may settle
towards the floor.
Check the GAS PRESSURE. Refer to pg. 10.
Do not try to light the burner manually. It is equipped
with an electronic ignition device which automatically
lights the burner.
Check for PROPER VENTING and COMBUSTIBLE
AIR to the water heater.
Purge the GAS and WATER LINES to remove any air
pockets.
Do not use this water heater if any part has been
submersed under water. Immediately call a qualified
service technician to inspect the water heater and to
replace any damaged parts.
•
•
•
•
•
•
•
•
CAUTION
IF YOU SMELL GAS:
Do not try to start the water heater.
Do not touch any electric switches; 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.
•
•
•
•
1. Once the above checks
have been completed,
please clean filter of any
debris. Refer to pg. 22
for instructions.
2. Fully open the manual
water control valve on
the water supply line.
3. Open a hot water tap
to verify that water is
flowing to that tap. Then
close the hot water tap.
4.Fullyopenthemanualgas
control valve installed.
5. Turn on the 120 volt 60
Hz power supply to the
water heater.
6. Now you are ready to
enjoy hours of endless
hot water.
Normal Operation
Flow rate to activate the 710:
1.9 l/min (0.5 GPM (US))
Flow rate to keep the 710 running:
1.5 l/min (0.4 GPM (US))
•
•
Without Remote Controller
1. Open a hot
water tap. 2. Mix cold water with the hot to
get the correct
temperature
water.
3. Close the hot
water tap.

20
With Remote Controller Installed: TM-RE30
(Optional)
1. Press the power ON/OFF button.
When ON,
green LED
is lit.
The temperature and the
time will be displayed on
the remote controller.
2. Set temperature. (Example 43°C (110°F))
Temperatures available in default mode
°C
38 40.5 43 46 49 52 55 57 60 63 65.5 68 71 74 77 79
°F
100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175
Temperatures available in High Temperature mode
°C
38 46 49 52 55 57 60 63 65.5 68 71 74 77 79 82 85
°F
100 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
DO NOT set to 85°C (185°F) if you use your 710 in recircula-
tion system. Refer to pg. 29.
3. Open a hot water tap. Mix cold water with the hot if you
need.
4. Close the hot water tap.
Hot Water temperatures over 52°C (125°F)
can cause severe burns instantly or death
from scalding.
The outlet hot water temperature of
the water heater is factory set at 49°C
(120°F).
Feel the water temperature before bath-
ing or showering.
•
•
To change the remote controller’s mode from Default Mode
to High Temperature Mode, please follow the procedures
below (the remote controller must be installed prior to oper-
ating these procedures):
DO NOT set to 185°C (85ºF) if you use your
710 water heater in a recirculation system.
This will cause damage to the heater and
void the warranty.
1. Turn off power to the remote controller by pressing the
“ON/OFF" button.
Lamp is OFF to indicate that power is off
2. Simultaneously press and hold both the “HOT” and
“COLD” buttons for
at least five seconds.
And then make sure
“1” (or “0”) is dis-
played on remote
controller. “1” is dis-
played for single
units, “0” is dis-
played for Easy-
Link / Multi-
Systems.
3. Press the “TIME” button. Make sure "oFF" and "F1" are
displayed on
remote controller.