Takagi T?KJr2?IN User manual

-Do not store or use 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 electric 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 performed
by a qualified installer, service agency or the
gas supplier.
FEATURING
ENDLESS HOT WATER
ON DEMAND USAGE
COMPACT, SPACE SAVING
ENERGY CONSERVATION
COMPUTERIZED SAFETY
NO PILOT LIGHT
EASY-LINK SYSTEM
510 (T-D2) models only
Gas Tankless Water Heater
Suitable for potable water heating and space-heating *
*Please refer to local codes for space-heating compliance.
If you have any questions, please
call or write to:
500 Tennessee Waltz Parkway
Ashland City, TN 37015
Toll Free:
1
-
877
-
737
-
2840
On
-
Demand Water Heater
Installation Manual and Owner’s Guide
Model
s
・ 110 Indoor (T-KJr2-IN) ・ 110 Outdoor (T-KJr2-OS)
・ 310 Indoor (T-K4-IN) ・ 310 Outdoor (T-K4-OS)
・ 510 Indoor (T-D2-IN) ・ 510 Outdoor (T-D2-OS)
WARNING
If the information in these
instructions is not followed
exactly, a fire or explosion
may result causing
property damage, personal injury or death.
ANSI
Z21.10.3
and CSA 4.3
510 (T
-
D2) models
only

Contents
2│Page
CONTENTS
SPECIFICATIONS…………………………………………………………………………………………..………………………...
INTRODUCTION…………………………………………………………………………………………………..………………….
SAFETY GUIDELINES…………….………………………………………………………………………………………..………..
INSTALLATION………………………………………………………………………………………………..…………………..….
General………………………………………………………………………………………………………………………..…..…
Clearances……………………………………………………………………………………………………………………………
Included Accessories…………….………………………………………………………………………………………..…..
Optional Items……………………………………………………………………………………………………………………..
High-Altitude Installations……………………………………………………………………………………………………
.
Venting Instructions……………………………………………………………………………………………………………
..
Gas Supply and Gas Pipe Sizing………......................................................................................
…
Water Connections……………..…………………………………………………………………………………………….…
Electrical Connections……………………………………………………………………..…………………………….......
Remote Controller Connections……..………………………………………………………………………………….
…
Pump Control Connections…………………………………………..………..………..
……………………………………
Easy-Link System...…………………………....…………………………………………………………………………..…..
..
APPLICATIONS...………………………………………………………………………………………………………………………
INITIAL OPERATION..………………………………………………………………………………………………………….……
OPERATING SAFETY…………………………………………………………………………………………………………………
NORMAL OPERATION…………………………………………………………………………………………………………..…
General………..……….………….…………………………………………………………………………………………………
Temperature Settings.…….……..……………………………………………………………………………………………
Flow…………………………………………………………………………………………………………………………………….
Freeze Protection System…….…………………………………………………………………………………………..…
Maintenance and Service………………………………………………………………………………………………….…
Unit Draining and Filter Cleaning…………………………………………………………………………………………
TROUBLESHOOTING……..……………………………………………………………………………………………………..…
General………..……….………….…………………………………………………………………………………………………
Error Codes.…………………….…..……………………………………………………………………………………………
…
COMPONENTS DIAGRAM……………………………………………………………………………………………………..…
PARTS LIST………………….………………………………………………………………………………………………..…………
OUTPUT TEMPERATURE CHART…………………………………………………………………………………………...…
LIMITED WARRANTY…………………………………………………………....…………………………………………….….
3
4
5
6
6
8
8
9
11
12
17
20
21
22
23
24
28
30
31
33
33
33
35
35
36
36
37
37
39
42
46
49
51
Installation Manual
Owner’s Guide

Specifications
3│Page
SPECIFICATIONS
Model
110
Indoor
(T-KJr2-IN)
110
Outdoor
(T-KJr2-OS)
310
Indoor
(T-K4-IN)
310
Outdoor
(T-K4-OS)
510
Indoor
(T-D2-IN)
510
Outdoor
(T-D2-OS)
Natural Gas Input
(Operating Range
)
Min: 19,500 Btu/h
Max: 1
40
,000 Btu/h
Min: 11,000 Btu/h
Max: 19
0
,000 Btu/h
Min: 11,000 Btu/h
Max: 199,000 Btu/h
Propane Input
(Operating Range)
Min: 19,500 Btu/h
Max: 140,000 Btu/h
Min: 11,000 Btu/h
Max: 190,000 Btu/h
Min: 11,000 Btu/h
Max: 199,000 Btu/h
Gas Connection ¾” NPT
Water Connections ¾” 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
2.0” WC
2.5” WC 2.0” WC
2.5” WC 2.0” WC 2.5” WC
Propane
2.5” WC 3.1” WC 3.7” WC 4.0” WC 3.7” WC 4.5” WC
Weight 33 lbs. 38 lbs. 39 lbs.
Dimensions H20.5” x W13.8” x D6.7”
H20.5” x W13.8” x D8.5”
Ignition Electric Ignition
Electric
Supply 120 VAC / 60 Hz
Consumption
Operation 73.1 W / 0.61 A 87.6 W / 0.73 A 89.8 W / 0.75 A
Standby 6.2 W / 0.05 A 6.2 W / 0.05 A 6.2 W / 0.05 A
Freeze-
Protection 111 W / 0.93 A 111 W / 0.93 A 111 W / 0.93 A
*40 psi or above is recommended for maximum flow
.
**The Manifold Pressure is the factory setting and generally should not need adjustment.
NOTE:
Check the rating plate to ensure this product matches your specifications.
In accordance with ANSI Z21.10.3, CO emission does not exceed 400 PPM for
normal input.
The manufacturer reserves the right to discontinue, or change at any time,
specifications or designs without notice and without incurring obligations.
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Introduction
4│Page
INTRODUCTION
*This diagram
illustrates tankless
water heater design
concepts only and
does not accurately
represent to the water
heater’s physical
description.

This manual provides information necessary for the installation, operation, and
maintenance of the water heater.

The model description is listed on the rating plate which is attached to the front panel
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 representative.

This equipment is an on-demand, tankless water heater designed to efficiently supply
endless hot water for your needs.

The principle behind tankless water heaters 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 initiates the fan motor and sends a signal to the igniter to create an ignition
spark.
5. The gas ignites and flames appear within the burner chamber.
6. Water circulates through the heat exchanger and then gets hot.
7. Using thermistors to measure temperatures throughout the water heater, the computer
modulates the gas and water valves to ensure proper output water temperature.

The 110 Indoor (T-KJr2-IN), 310 Indoor (T-K4-IN) and 510 Indoor (T-D2-IN) models are
to be only installed indoor (direct-vent convertible). The 110 Outdoor (T-KJr2-OS), 310
Outdoor
(
T
-
K4
-
OS) and 510 Outdoor (T
-
D2
-
OS) models ar
e to
be only installed outdoor.

Safety Guidelines
5│Page

W
ater temperature
s over 125°F
(
52
°
C
)
can cause severe burns instantly or
death
from scalding. The water temperature is set at 122°F (50°C) 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. 20 when
installing your water heater.
Do not use this appliance if any part has been in contact with or been immersed
in water. 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. 35 for more
information
.
SAFETY GUIDELINES
SAFETY DEFINITIONS
Indicates an imminently hazardous situation which, if not avoided, will result in
death or serious injury.
Indicates an imminently hazardous situation which, if not avoided, could result
in death or serious injury.
Indicates an imminently hazardous situation which, if not avoided, could result
in minor or moderate injury.
GENERAL
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 the 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. 7).
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.
WARNING
CAUTION
DANGER
WARNING

Installation
6│Page
INSTALLATION
GENERAL
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. 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.
3. The manifold gas pressure is preset at the factory. It is computer controlled and should not
need adjustment.
4. Maintain proper space for servicing. Install the unit so that it can be connected or removed
easily. Refer to the Clearances Section on p. 8 for proper clearances.
5. The water heater must be installed in a location where the proper amount of combustible air
will be available to it at all times without obstructions.
6. The electrical connection requires a means of disconnection, to terminate power to the water
heater for servicing and safety purposes.
7. 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 p. 15).
8. Particles from flour, aerosols, and other contaminants may clog the air vent or 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.
9. If you will be installing the water heater 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 causing damage to the water heater.
10. For the 110 Indoor (T-KJr2-IN), 310 Indoor (T-K4-IN) and 510 Indoor (T-D2-IN) models:
These units may be converted to a direct-vent (sealed combustion) appliance by installing a
direct-vent conversion kit Part No. 9007667005 (TK-TV10) which will bring in all required
combustible air from outside the building. When installing the direct-vent conversion kit,
please follow all instructions included with the kit.
If the water heater is used as a direct-vent appliance, the unit requires a 3” 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.
Terminating the venting through a sidewall is recommended for the direct-vent system.
Running the exhaust vent and the intake pipe parallel is recommended.
Terminating the exhaust and intake on the same wall / surface is recommended.
Terminating in the same pressure zone allows for pressure balancing, which prevents
nuisance shutdowns.
11. For the 110 Outdoor (T-KJr2-OS), 310 Outdoor (T-K4-OS) and 510 Outdoor (T-D2-OS) models:
To be installed outdoors and only in areas with mild, temperate climates.

Installation
7│Page
Installation and service must be performed by a qualified installer (for
example, a licensed plumber or gas fitter), otherwise the warranty will be
void.
The installer (licensed professional) is responsible for the correct installation
of the water heater and for compliance with all national, state/provincial,
and local codes.
The manufacturer does not recommend installing the water heater in a pit or
location where gas and water can accumulate.
Do not have the vent terminal pointing toward any operating window, door, or
opening into a building.
Do not install next to any source of airborne debris, such as a clothes dryer,
that can cause debris to be trapped inside the combustion chamber, unless
the system is direct-vented.
The manufacturer does not recommend installing the water heater in an
attic due to safety issues. If you install the water heater in an attic:
Make sure the unit will have enough combustion air and proper ventilation.
Keep the area around the water heater clean. When dust collects on the
flame sensor, the water heater will shut down on an error code.
If the above conditions cannot be met, use the direct vent conversion kit
Part No. 9007667005 (TK-TV10).
Place the unit for easy access for service and maintenance.
A drain pan, or other means of protection against water damage, is
required to be installed under the water heater in case of leaks
.

The warranty will not cover damage caused by water quality.
Only potable water or potable water / glycol mixtures can be used with this
water heater. Do not introduce pool or spa water, or any chemically
treated water into the water heater.
Water hardness levels must not exceed 7 grains per gallon (120 ppm) for
single family domestic applications or more than 4 grains per gallon (70
ppm) for all other types of applications. Water hardness leads to scale
formation and may affect/damage the water heater. Hard water scaling
must be avoided or controlled by proper water treatment.
Water pH levels must be between 6.5 and 8.5
Well water must be treated.
Do not install the unit where water, debris, or flammable vapors may get into
the flue terminal.
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 water heater 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
leakage at some time in the life of the product 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.
CAUTION
WARNING

Installation
8│Page
CLEARANCES
Mode
l
Top
Bottom
Front
Back
Sides
110 Indoor* (
T
-
KJr2
-
IN
)
*
12
”
12
”
24
”
1
”
2
“
110 Outdoor (
T
-
KJr2
-
OS
)
36
”
12
”
24
”
1
”
2
“
Model
Top
Bottom
Front
Back
Sides
310 Indoor
* (
T
-
K4
-
IN
)
*
12
”
12
”
24
”
1
”
2
“
310 Outdoor (
T
-
K4
-
OS
)
36
”
12
”
24
”
1
”
2
“
Model
Top
Bott
om
Front
Back
Sides
510 Indoor* (
T
-
D2
-
IN
)
*
12
”
12
”
24
”
1
”
2
“
510 Outdoor (
T
-
D2
-
OS
)
36
”
12
”
24
”
1
”
2
“
*Standard indoor installations and direct-vent indoor installations have the same clearances.
INCLUDED ACCESSORIES
Check that these items below are included with the water heater.
1. Installation Manual and
Owner’s Guide
2. Product Registration Card 3. Communication Cable
510 (T-D2) models only
Qty: 1
Qty: 1
Qty: 1
Bottom
Side
Top
Side
Front
Back
Maintain a
ll clearances around
the water heater.

Installation
9│Page
OPTIONAL ITEMS
Model
110 Indoor
(T-KJr2-IN)
110 Outdoor
(T-KJr2-OS)
310 Indoor
(T-K4-IN)
310 Outdoor
(T-K4-OS)
510 Indoor
(T-D2-IN)
510 Outdoor
(T-D2-OS)
9007666005
(
TK
-
RE02
)
✔ ✔ ✔ ✔
9007603005
(
TM
-
RE30
)
✔ ✔
9007678005
(
TK
-
BF01
)
✔ ✔ ✔
9007667005
(
TK
-
TV10
)
✔ ✔ ✔
9007670005
(
TK
-
PC01
)
✔ ✔ ✔ ✔
9007671005
(
TK
-
PCJr2
)
✔ ✔
90076
74005
(
TK
-
RB02
)
✔ ✔ ✔
9007608005
(TK-KPWL4)
9007609005
(
TK
-
KPWH4
)
✔ ✔ ✔
9007680005
(
TK
-
KPCT43
)
✔ ✔ ✔
1
.
Temperature Remote Controller
:
9007666005
(TK-RE02)
The Temperature Remote
Controller has two functions. It
allows the output temperature
from the water heater to be
adjusted within the range of
99 °F to 167 °F, and it also
works as a diagnostic tool that
will give a concise error code whenever there is a
problem with the unit. The temperature options
are 99°F, 100°F, 102°F, 104°F, 106°F, 108°F, 109°F,
111°F, 113°F, 115°F, 117°F, 122°F, 131°F, 140°F,
158°F, and 167°F. See the trouble shooting section
for information on possible error codes.
2
.
Temperature Remote Controller
:
9007603005
(TM-RE30)
The Temperature Remote
Controller has two functions. It
allows the output temperature
from the water heater to be
adjusted within the range of
99 °F to 185 °F, and it also
works as a diagnostic tool that
will give a concise error code whenever there is a
problem with the unit. The temperature options
are 99°F, 100°F, 102°F, 104°F, 106°F, 108°F, 110°F,
111°F, 113°F, 115°F, 117°F, 122°F, 131°F, 140°F,
149°F, 158°F, 167°F, 176°F and 185°F. See the
trouble shooting section for information on
possible error codes.
3. Backflow Preventer: 9007678005 (TK-BF01)
The Backflow preventer prevents
the backflow of air through the
exhaust vent. This helps prevent
harmful exhaust gases from
entering the home, as well as
helping to prevent the unit from
freezing in areas where cold air can be blown or
drawn into the exhaust system. Install this vent
damper in accordance with the installation
instructions and any applicable codes.
4. Direct-Vent Conversion Kit: 9007667005
(TK-TV10)
This kit can be used to
convert the water
heater from a
standard vent system
to a direct-vent (or
sealed combustion)
system. Install this
conversion kit in accordance with the installation
instructions and any applicable codes.

Installation
10│Page
5. Pipe Covers: 9007670005 (TK-PC01) and
9007671005 (TK-PCJr2)
The pipe cover protects the
plumbing pipes to the water heater
from unexpected adjustments.
This pipe cover is fixed to the
bottom of the water heater, which
hides the plumbing and improves
the visual aspects of the whole
installation
for the water heater.
6. Recess box: 9007674005 (TK-RB02)
The Recess box will allow for
“clean” installations. The water
heater fits inside the recess box,
which hides and protects the
whole water h
eater and plumbing.
The Recess box will fit in-between
most wall studs.
7. T-Vent Wall Thimble with Termination: 9007608005 (TK-KPWL4) and 9007609005 (TK-KPWH4)
These terminations are used when venting out through the wall
and are compatible with the T-Vent pipe system.
These terminations are special stainless steel vents for gas
appliances and are UL listed as Category II, III and IV. There are
two types of terminations: the Louver termination and the Hood
termination. For different wall thicknesses, there are two ranges
of lengths available (refer to the venting brochure for details).
Install these vent terminations in accordance with their
installation instructions and any applicable local codes.
8. Direct-Vent Concentric Termination: 9007680005 (TK-KPCT43)
Used when terminating direct-vent (sealed-combustion) systems,
with direct-vent models that require a 3” intake and a 4” exhaust.
This concentric termination provides the convenience of only
having to make one penetration through a sidewall instead of two
separate penetrations for the intake and exhaust piping. The
termination includes a bird screen, restricting small animals,
pests, and foreign objects from entering into the vent system.
This sidewall termination is available in three different sizes, to
cover all ranges of wall thicknesses
.
Direct
-
vent Concentric
Termination
Part#
Covering wall thickness
9007680005 (
TK
-
KPCT43
-
1
)
3.9
”
–
7.1
”
9007772005 (
TK
-
KPCT43
-
2
)
6.9
”
–
10.1
”
9007773005 (
TK
-
KPCT43
-
3
)
9.8
”
–
13.0
”
Louver
Termination
9007608005
(TK-KPWL4)
Hood
Termination
9007609005
(TK-KPWH4)