Takagi T-K3-SP, T-K3-OS Installation Manual And Owner's Manual

T-K3-OS and T-K3-SP

Instantaneous Water Heater
Installation Manual and Owner’s Guide

WARNING

This product must be
installed and serviced by a
licensed plumber, a licensed
gas fitter, or a professional
service technician. Improper
installation and/or operation,
or installation by an
unqualified person, will void
the warranty.

Flash Water Heater™

Model T-K3-OS

Suitable for potable water heating and space heating

• ENDLESS HOT WATER

• ON DEMAND USAGE

• COMPACT, SPACE SAVING

• ENERGY CONSERVATION

• COMPUTERIZED SAFETY

• NO PILOT LIGHT

FEATURING

Flash Water Heater™

Model T-K3-SP

TAKAGI Industrial Co. USA Inc.

5 Whatney
Irvine, CA 92618
Toll Free: [phone] USA
Toll Free: [phone] CANADA

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WARNING

If the information in this
manual is not followed
exactly, a fire or explosion
may result, causing property
damage, personal injury, or
death.

CONTENTS

SPECIFICATION

SPECIFICATIONS……………………...
INTRODUCTION…………………….…
SAFETY GUIDELINES…………….…..
INSTALLATION……………………..….
General…………………………….…
Accessories…………………………..
Outdoor Installation………………….

Indoor Installation…………………....

Venting Instructions
Gas Supply / Gas Pipe Sizing…...…
Water Connections……………..……
Pressure Relief Valve…………….…

Electrical Connections……………....

Remote Controller Connection…..…
Initial Operation………………………
NORMAL OPERATION…………..……
Normal Operation…………………...
Flow………………………………...…
Freeze Protection System …………
Temperature Setting ………………..
Maintenance and Service…………..
TROUBLESHOOTING…………………
WIRING DIAGRAM…………………….
OPERATING SAFETY…………………
APPLICATIONS………………………..
Space Heating……………………….
Dual-Purpose Heating………………
Re-Circulation ……………………….
OPTIONAL ITEMS……………………..
COMPONENTS DIAGRAM &

OUTPUT TEMPERATURE CHART….
WARRANTY ……………………………

(T-K3-SP ONLY) …

PARTS LIST……….

2
3
4
5
6
6
7
9
10
14
16
17
18
18
19
20
20
21
21
22
23
24
27
28
30
30
31
32
33

34
38
39

Natural Gas Input
(Operating Range)

LPG Input
(Operating Range)

Gas Connection ¾” NTP

Water Connections

Water Pressure 15 - 150 psi*

Natural Gas Pressure
Inlet

LP Gas
Pressure Inlet

Manifold Pressure of
the T-K3-OS

Manifold Pressure of
the T-K3-SP

Weight 40 lbs.
Dimensions
Ignition Electric Ignition

Electric

*50 psi or above is recommended for maximum flow

NOTE

T-K3-OS and T-K3-SP

Min: 11,000 Btu/h

Max: 190,000 Btu/h

Min: 11,000 Btu/h

Max: 190,000 Btu/h

¾” NTP

Min. 5.0” WC

Max. 10.5” WC

Min. 8.0” WC

Max. 13.5” WC

Natural: 2.8” WC

Supply 120VAC (60Hz)

Consumption
of the T-K3-
OS

Consumption
of the T-K3-
SP

Propane: 3.1” WC

Natural: 2.4” WC

Propane: 4.1” WC

H20.5” x W13.8” x D8.5”

Operation
Standby

Freeze­Protection

Operation
Standby
Freeze-

Protection

92 W

6.2 W
111 W
92 W

6.2 W
111 W

Manufacturer reserves the right to discontinue, or change at any time, specifications or
designs without notice and without incurring obligations.

-Check the rating plate to ensure this product
matches your specifications.

-In accordance with ANSI Z21.10.3 and SCAQMD
Rule 1146.2, CO emission does not exceed 400 PPM
for normal input.

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INTRODUCTION

• This manual provides information necessary for the installation, operation, and
maintenance of the Model T-K3-OS/SP 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 Takagi or

its local representative.

• The T-K3-OS/SP Water Heater is an instantaneous, tankless water heater designed to
efficiently supply endless hot water for your needs.

• The principle behind the T-K3-OS/SP Water Heater is simple:

1. A hot water tap is turned on.

2. Water enters the heater.

3. The water flow sensor detects the
water flow.

4. The computer automatically
ignites the burner.

5. Water circulates through the heat
exchanger and then gets hot.

6. The computer will modulate the
gas supply valve and water flow
to produce the right amount of hot
water at the correct temperature.

7. When the tap is turned off, the
unit shuts down.

*This diagram is to illustrate Takagi’s tankless water
heater design concepts only and may not be accurate
to the T-K3-OS/SP’s physical description.

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SAFETY GUIDELINES

• Installation and service must be performed by a qualified installer (for

example, a licensed plumber or gas fitter), otherwise the warranty by Takagi
will be void.

• The installer (licensed professional) is responsible for the correct

installation of your Flash T-K3-OS/SP Water Heater and for compliance with

WARNING

PLEASE READ THIS MANUAL CAREFULLY AND FOLLOW ALL DIRECTIONS.

1. Follow all local codes, or in the absence of local codes, follow the most recent edition of
the National Fuel Gas Code: ANSI Z223.1/NFPA 54 in the USA or CAN/CSA B149.1
Natural Gas, Propane Installation Code in Canada.

2. Properly ground the unit in accordance with all local codes or in the absence of local
codes, with the National Electrical Codes: ANSI/NFPA 70 in the USA or CSA standard
C22.1 Canada Electrical Code Part 1 in Canada.

3. Carefully plan where you intend to install your T-K3-OS/SP 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 p. 5).

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 Takagi.

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.

all national, state/provincial, and local codes.

*For all units installed in the state of Massachusetts, it is required that the installer
either be a licensed plumber or licensed gas fitter.

GENERAL

RATING PLATE

WARNING

• Water temperatures over 125ºF can cause severe burns instantly or death from
scalding. The water temperature is set at 122ºF (50ºC) from the factory to minimize any
scalding risk. Before bathing or showering always check the water temperature.

• Do not store or use gasoline or other flammables, vapors, or liquids in the

vicinity of this appliance.

• Do not reverse the water and/or gas connections as this will damage the gas valves and

can cause severe injury or death. Follow the diagram on p. 16 when installing your water
heater:

• Do not use this appliance if any part has been in contact with or been immersed in water.

Prohibited

Immediately call a licensed plumber, a licensed gas fitter, or a professional service
technician to inspect and/or service the unit if necessary.

• Do not disconnect the electrical supply if the ambient temperature will drop below

freezing. The Freeze Prevention System only works if the unit has electrical power. The
warranty will not be covered if the heat exchanger is damaged due to freezing. Refer to
the section on the Freeze Prevention System on p. 21 for more information.

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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.

• The T-K3-OS must be installed OUTDOORS ONLY. DO NOT install the

T-K3-OS indoors. The T-K3-SP can be installed either indoors or outdoors.

• The warranty will not cover damage caused by water quality. Water

hardness may affect the water heater. Water heater may be damaged.

• The water heater must be installed vertically.

CAUTION

WARNING

• If the T-K3-SP is installed in a beauty salon, some chemicals used in a

beauty salon may affect the flame sensor. Water heater may not work
properly. TAKAGI recommends isolating the T-K3-SP from beauty

salon elements.

• Although the T-K3-OS/SP is designed to operate with minimal sound,

TAKAGI 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
leakage at some time in the life of the product does exist. If there is no
drain, Takagi 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.

• TAKAGI does not recommend installing unit in an attic due to safety

issues. If you install your T-K3-SP in an attic:

• Make sure your unit will have enough combustion air and proper

ventilation.

• Keep the area around your T-K3-SP clean. When dust collects on the

flame sensor, the water heater will shut down on errors.

• Locate unit for easy access for service and maintenance.

• A drain pan is required to be installed under the water heater in case of

leaks.

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GENERAL

1. The manifold gas pressure is preset at the factory. It is computer controlled and should
not need adjustment.

2. Maintain proper space for servicing. Install the unit so that it can be connected or

removed easily. Refer to p. 7 and p. 9 for proper clearances.

3. The electrical connection requires a means for switching off the power supply.

4. If you will be installing the unit in a contaminated area with a high level of dust, sand,

flour, aerosols or other contaminants, they can become airborne and enter and build up
within the fan and burner causing damage to the unit. Particles from flour, aerosols, and
other contaminants may reduce the functions of the rotating 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.

5. Do not install the unit where the exhaust vent/opening is pointing into any opening in a
building or where the noise may disturb your neighbors. Make sure the vent
termination/exhaust opening meets the required distance by local code from any
doorway or opening to prevent exhaust from entering a building (refer to p. 13).

ACCESSORIES

Check that the installation manual and the warranty card are included with the unit.

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OUTDOOR INSTALLATION

1. Follow all local codes, or in the absence of local codes, follow the most recent edition of

the National Fuel Gas Code: ANSI Z223.1/NFPA 54 in the USA or CAN/CSA B149.1
Natural Gas, Propane Installation Code in Canada.

2. Outdoor installation for mild climates only.

3. When installing the T-K3-SP outdoors, ensure that the T-K3-SP is set for outdoor

installation. Locate the bank of dipswitches at the bottom-right corner of the computer
board. The ‘OUT’ dipswitch on the computer board should be switched to ‘ON’ (up).

For the T-K3-OS, no dipswitches need to be changed.

4. The outdoor vent cap must be used when the T-K3-SP is installed outdoor. Takagi

The dipswitch setting, as shown to
the right, is for the T-K3-SP ONLY.

requires the use of its part No. TK-TV04.

Make sure power to the unit is
turned OFF before changing
the dipswitch settings.

The dark square is the direction
the dipswitch should be set to.

5. When installed outdoors, the T-K3-OS/SP water heater shall be wall mounted only.
Locate the water heater in an open, unroofed area and maintain the following minimum
clearances:

OS SP

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WARNING

Do not install the heater where water, debris
or flammable vapors may get into the flue
terminal/opening. This may cause damage to
the heater and void the warranty.

Do not have the vent terminal/opening
pointing toward any opening into a building.
Do not locate your heater in a pit or location
where gas and water can accumulate.

Prohibited Prohibited

Do not install this water heater under an
overhang less than 3 feet from its top or
eaves. The area under an overhang must be
open to three sides.

Do not install the water heater vent terminator
within 1 ft. in the USA of any air intake or
building opening, and with in 3 ft. in Canada
of any air intake or building opening (Refer to
p.13).

Avoid locating the water heater exhaust
opening near any air intake devices. These
fans can pick up the exhaust flue products
from the water heater and return them to the
building. This can create a health hazard.

Prohibited

T-K3-OS

T-K3-SP

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INDOOR INSTALLATION (T-K3-SP ONLY)

1. Follow all local codes, or in the

absence of local codes, follow
the most recent edition of the
National Fuel Gas Code: ANSI
Z223.1/NFPA 54 in the USA or
CAN/CSA B149.1 Natural Gas,
Propane Installation Code in
Canada.

2. When installed indoors, the T-K3­SP water heater shall be located
in an area to maintain the
following minimum clearances
around the unit:

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 ANSI Standard Z223.1 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 the T-K3-SP:

Water heater size

When drawing
outside the building

make-up air from

When drawing make-up
the building (from other rooms within)

SP

air from inside

190 Sq. IN

MAX 190,000 BTU

12.7 Sq. IN

When combustion air is supplied
from outside the building, an
opening communicating directly
with the outside should have a
minimum free area of one
square inch 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 opening
communicating with the rest of the
dwelling should have a minimum free
area of one square inch per 1,000
BTUH input of the total input rating of
water heater in the enclosed area.
This opening should never be less
than 190 sq. in.

Combustible Air Supplied by Mechanical fan or Make up air device

The T-K3-SP water heater is equipped with a combustible air sensor that will shut off the unit
when inadequate combustible 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.

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VENTING INSTRUCTIONS (T-K3-SP ONLY)

This water heater must be vented in accordance with the section “Venting of Equipment" of the
latest edition of the Natural Fuel Gas Code: The ANSI Z223.1, All applicable local building
codes, Section 7 of the CAN/CSA B149.1 Natural Gas in Canada, Propane Installation Code in
Canada.

WARNING: Improper venting of this appliance can result in excessive levels of
carbon monoxide which can result in severe personal injury or death.

EXHAUST VENT (T-K3-SP ONLY)

This is a Category III appliance and must be vented accordingly. 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 adhesive tape having a minimum temperature rating of
350ºF. For best results, a vent system should be as short and straight as possible.

1. The T-K3-SP is a Category III appliance and must be vented accordingly with any 4” vent
approved for use with Category III or Special BH type gas vent.

2. The following are 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. The maximum length of exhaust vent piping must not exceed 50 ft. deducting 5 ft. for each
elbow used in the venting system. Do not use more than 5 elbows.

Diameter Max. No. of Elbow Max. Vertical or Horizontal run in Length

4” 5 Ea. 50 ft.

*For each elbow added, deduct 5 ft. from max. Vent length.

No. of Elbows Max. Vertical or Horizontal Length

0 50 ft.
1 45 ft.
2 40 ft.
5 25 ft.

6. When the horizontal vent run exceeds 5 ft., support the vent run at 3 ft. intervals with

overhead hangars.

7. Takagi will not be responsible for any damage to the water heater caused by condensation
from the vent. For horizontal runs, slope the vent run downwards toward the vent terminal
at a rate of ¼” per foot. For horizontal runs that do not slope downward and for vertical
runs, installing a condensate drip is recommended. Please refer to p. 12 for the diagrams.

When installing the vent system, all applicable national and local codes must be
followed. If you install thimbles, fire stops or other protective devices and they
penetrate any combustible or noncombustible construction, be sure to follow all
applicable national and local codes.

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VENT TERMINATION (T-K3-SP ONLY)

WARNING: Improper installation can cause nausea or asphyxiation, severe injury

or death from carbon monoxide and flue gases poisoning. 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 ANSI Z223.1/NFPA 54, or in Canada with CAN/CSA­B149.1 and local applicable codes.

• The sidewall vent terminator, TK-TV01, is recommended when the water heater is vented

through a sidewall.

General rules for venting the T-K3-SP water heater are:

1. Place the water heater as close as possible to the vent terminator.

2. The vent collar of the water heater must be fastened directly to an unobstructed vent pipe.

3. Do not weld the vent pipe to the water heater collar.

4. Do not cut the vent collar of the unit.

5. The weight of the vent stack must not rest on the water heater.

6. The vent must be easily removable from the top of the water heater for normal service and

inspection of the unit.

7. The water heater vent must not be connected to any other gas appliance or vent stack.

8. Avoid locating the water heater vent terminator near any air intake devices. These fans

can pick up the exhaust flue products from the water heater and return them to the
building. This can create a health hazard.

9. Avoid using an oversized vent pipe or using extremely long runs of the pipe.

10. Locate the vent terminator so that it cannot be blocked by any debris, at any time . Most

codes require that the terminator be at least 12 inches above grade, but the installer may
determine if it should be higher depending on the job site condition and applicable codes.

11. For rooftop venting, a rain cap must be installed.

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• 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 T-K3-SP vent.

• Use 4” category III approved or Special BH, single or double wall stainless steel vent

pipe.

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