Residential / Commercial Gas
Tankless Water Heaters
Tankless Non-Condensing Water Heaters
INDOOR MODELS
T-KJr2-IN, T-K4-IN, T-D2-IN
Fully modulating, gas fired, tankless water heater specifically designed for
residential and commercial applications. Supplies hot water to domestic hot water
systems (directly or indirectly) which can be used with storage tanks, recirculation
systems, hydronic heating systems, radiant floor heating systems, and/or
combined domestic & heating applications.
FEATURES:
VENTING AND COMBUSTION
MAXIMUM FLOW RATES UP TO
10.0 GPM
• Vertical or Horizontal Installation
AVAILABLE IN NATURAL GAS
OR PROPANE (LP)
OUTDOOR MODELS INCLUDE
REMOTE CONTROL AS A
STANDARD FEATURE
INDOOR MODELS INCLUDE
BOTH A REMOTE CONTROL
AND POWER CORD AS
STANDARD FEATURES
LOW NOx EMISSIONS
COMPLIES WITH LEAD FREE
STANDARDS
HEAT EXCHANGER (T-D2
MODELS) IS CONSTRUCTED OF
COMMERCIAL GRADE COPPER
SAFETY FEATURES:
• Built in Freeze Protection
• Manual Reset Hi-Limit
• Overheat Cutoff Fuse
• Inlet and Outlet Thermistors for
Constant Temperature Monitoring
• 4” Category III Vent
• 50’ Max Length, 5 Elbows max (90°
elbows = 5’ equivalent length)
• Power Vent Power Vent or Power
Direct Vent
• Electronic Ignition - No Pilot Light
• 3” Combustion Air Intake (with
optional kit)
OPTIONAL ACCESSORIES
• Complete Line of Category III
Venting
• Recess Box (outdoor models)
• Pipe Cover
OUTDOOR MODELS
T-KJr2-OS, T-K4-OS, T-D2-OS
• Direct Vent Conversion Kit (indoor
models)
• Isolation Valve Kits
• Backflow Preventer
• Concentric Termination Kits
WARRANTY
• 15-year limited warranty on heat
exchanger in residential applications
• 10-year limited warranty on
heat exchanger in commercial
applications
• 5-year limited warranty on all parts
• Flame Sensor
EASY-LINK UP TO 4 UNITS
(T-D2 MODELS):
• With no additional parts or
accessories needed
510 models
ANSI Z21.10
©2015 Takagi www.takagi.com
Page 1 of 4
TRGSS01613
Residential / Commercial Gas
Tankless Water Heaters
MODEL
NUMBER
GAS CONSUMPTION
INPUT
INLET GAS PRESSURE ENERGY
DIMENSIONS IN INCHES UNIT
MAXIMUM
HOT/COLD
GAS
FACTOR
WEIGHT
GPM*
CONNECTIONS CONNECTION
MINIMUM MAXIMUM MINIMUM MAXIMUM
(EF)
HEIGHT WIDTH DEPTH (LBS)
BTU/H
BTU/H
IN. W.C.
IN. W.C.
TYPE
Indoor Models
T-KJr2-IN-NG
T-KJr2-IN-LP
T-K4-IN-NG
T-K4-IN-LP
T-D2-IN-NG**
T-D2-IN-LP**
Natural
Propane
Natural
Propane
Natural
Propane
19,500
19,500
11,000
11,000
11,000
11,000
140,000
140,000
190,000
190,000
199,000
199,000
5.0
8.0
5.0
8.0
5.0
8.0
10.5
14.0
10.5
14.0
10.5
14.0
0.82
0.82
0.82
0.82
0.82
0.82
6.6
6.6
8
8
10
10
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
20-1/4
20-1/4
20-1/4
20-1/4
20-1/4
20-1/4
13-3/4
13-3/4
13-3/4
13-3/4
13-3/4
13-3/4
7-3/4
7-3/4
9-1/2
9-1/2
9-1/2
9-1/2
33
33
38
38
39
39
Natural
Propane
Natural
Propane
Natural
Propane
19,500
19,500
11,000
11,000
11,000
11,000
140,000
140,000
190,000
190,000
199,000
199,000
5.0
8.0
5.0
8.0
5.0
8.0
10.5
14.0
10.5
14.0
10.5
14.0
0.82
0.82
0.82
0.82
0.82
0.82
6.6
6.6
8
8
10
10
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
3/4” NPT
20-1/4
20-1/4
20-1/4
20-1/4
20-1/4
20-1/4
13-3/4
13-3/4
13-3/4
13-3/4
13-3/4
13-3/4
7-3/4
7-3/4
9-1/2
9-1/2
9-1/2
9-1/2
33
33
38
38
39
39
Outdoor Models
T-KJr2-OS-NG
T-KJr2-OS-LP
T-K4-OS-NG
T-K4-OS-LP
T-D2-OS-NG**
T-D2-OS-LP**
15-150 PSI water pressure. 40 PSI or above recommended for maximum flow.
*Current numbers based on factory testing, 0.5 GPM required for activation, 0.4 GPM required for continuous fire after initial ignition.
**Suitable for commercial applications.
Indoor models are certified from sea level to 6,000 ft. elevation. Outdoor models are certified from sea level to 6,000 ft. elevation.
T-KJr2 INDOOR DIMENSIONS
T-KJr2 OUTDOOR DIMENSIONS
CLEARANCES: TOP 12”, BOTTOM 12”, FRONT 24”, BACK 1”, SIDES 3”
CLEARANCES: TOP 36”, BOTTOM 12”, FRONT 24”, BACK 1”, SIDES 3”
4" (101 mm)
1-3/4" (45mm)
1" (26mm)
2-1/4" (56 mm) COLD
3-7/8" (98mm) GAS
4-7/8" (123mm) 120V
4-7/8" (124mm) HOT
7-3/4" (196mm)
T-K4 and T-D2 INDOOR DIMENSIONS
19-3/8" (493mm)
20-1/4" (520mm)
1-7/8" (47mm)
120V 1-3/8" (36mm)
HOT 5-1/4" (133mm)
GAS 4-7/8" (124mm)
©2015 Takagi www.takagi.com
1" (26mm)
COLD 2-7/8" (71mm)
120VAC 3-7/8" (99mm)
GAS 5-1/4" (135mm)
HOT 6-1/2" (164mm)
9-1/2" (241mm)
20-1/4" (520mm)
1-3/4" (45mm)
4-3/8" (113mm)
7-7/8" (203mm)
1-3/4" (45mm)
5" (128mm)
1-7/8" (47mm)
COLD 3-1/4" (84mm)
120V 1-3/8" (36mm)
HOT 5-1/4" (133mm)
GAS 4-7/8" (124mm)
19-3/8" (493mm)
1-3/4" (45mm)
4-3/8" (113mm)
COLD 3-1/4" (84mm)
1-5/8" (43mm)
13-3/4" (350mm)
10" (254mm)
4" (101 mm)
1-3/8" (36mm)
21-3/8" (544mm)
CLEARANCES: TOP 36”, BOTTOM 12”, FRONT 24”, BACK 1”, SIDES 3”
1-5/8" (43mm)
1-3/4" (45mm)
1" (26mm)
2-1/4" (56 mm) COLD
3-7/8" (98mm) GAS
4-7/8" (123mm) 120V
4-7/8" (124mm) HOT
7-3/4" (196mm)
120V 1-3/8" (36mm)
GAS 4-7/8" (124mm)
T-K4 and T-D2 OUTDOOR DIMENSIONS
CLEARANCES: TOP 12”, BOTTOM 12”, FRONT 24”, BACK 1”, SIDES 3”
13-3/4" (350mm)
10" (254mm)
1-7/8" (47mm)
COLD 3-1/8" (79mm)
HOT 5-1/4" (133mm)
1-5/8" (43mm)
120V 1-3/8" (36mm)
GAS 4-7/8" (124mm)
20-1/4" (520mm)
21-3/8" (544mm)
20-1/4" (520mm)
21-3/8" (544mm)
2-1/4" (56mm)
1-7/8" (47mm)
COLD 3-1/8" (79mm)
HOT 5-1/4" (133mm)
7-7/8" (203mm)
1-3/4" (45mm)
1-3/4" (45mm)
21-3/8" (544mm)
1-3/4" (45mm)
13-3/4" (350mm)
10" (254mm)
4" (102mm)
2-1/4" (57mm)
13-3/4" (350mm)
10" (254mm)
1" (26mm)
COLD 2-7/8" (71mm)
120VAC 3-7/8" (99mm)
GAS 5-1/4" (135mm)
HOT 6-1/2" (164mm)
9-1/2" (241mm)
Page 2 of 4
TRGSS01613
120
40
100
80
30
Head (ft)
Pressure Loss (psi)
310 Indoor/Outdoor Pressure Loss
50
Residential / Commercial Gas
60
20
40
10
20
0
0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Tankless Water Heaters
9.0
110
Flow Rate (gpm)
T-KJr2 MODELS
110 Indoor/Outdoor Pressure Loss
Comparison of Flow Rates vs. Temperature Rise
30
Set temperature of 122°F or lower
Set temperature of 131°F or higher
80
20
70
100
6
80
5
60
120
40
100
60
10
50
8020
600
040
300.0
2.0
4.0
20
6.0
8.0
40
Flow Rate (gpm)
Flow Rate (gpm)
510 Indoor/Outdoor Pressure Loss
7
4
3
2
Head (ft)
Pressure Loss (psi)Pressure Loss (psi)
40
120
Head (ft)
50
1
0
0
10
0
40
0
0.0
2.0
4.0
6.0
8.0
10.0
100
80
30
60
20
8
7
40
10
20
0
0
4.0
5.0
6.0
7.0
8.0
Flow Rate (gpm)
40
3.0
140
9
Head (ft)
120
2.0
120
Comparison of Flow Rates vs. Temperature Rise
50
1.0
100
T-K4 MODELS
310 Indoor/Outdoor Pressure Loss
0.0
60
80
Temperature Rise (°F)
310
12.0
Flow Rate (gpm)
Pressure Loss (psi)
20
20
6
5
4
3
2
1
9.0
0
0
Flow Rate (gpm)
20
40
60
80
Temperature Rise (°F)
100
120
140
510
T-D2 MODELS
110 Indoor/Outdoor Pressure Loss
120
50
510 Indoor/Outdoor Pressure Loss
50
6020
40
30
20
0.0
10
2.0
4.0
2.0
4.0
6.0
Head (ft)
10.0
9.0
8.0
7.0
6.0
400
5.0
8.020
4.0
3.0
Flow Rate (gpm)
0
0.0
6.0
11.0
Flow Rate (gpm)
40
80
12.0
Head (ft)
120
60
100
60
10
0
Set temperature of 131°F or higher 80
70
20
Pressure Loss (psi)
Pressure Loss (psi)
Set temperature of 122°F or lower
30 80
Comparison of Flow Rate vs. Temperature Rise
100
40
0
8.0
10.0
2.0
12.0
1.0
Flow Rate (gpm)
0.0
0
20
40
60
80
100
120
140
Temperature Rise (°F)
310 Indoor/Outdoor Pressure Loss
120
40
100
oss (psi)
©2015 Takagi www.takagi.com
30
80
Page 3 of 4
TRGSS01613
d (ft)
50
Residential / Commercial Gas
Tankless Water Heaters
Specification for the T-D2-IN or T-D2-OS
The fully modulating, on-demand, gas fired tankless water heater shall be Takagi Tankless Water Heater model T-D2-IN or T-D2-OS,
having a maximum input rating of 199,000 Btu/h and available in NG or LP. The heater shall have ¾ in. male NPT water and gas
connections. The inlet gas supply pressures shall be 5.0 in. WC (min.) up to 10.5 in. WC (max) for NG and 8.0 in. WC (min.) up to 14
in. WC (max.) for LP. The heater shall be supplied with a temperature remote, 9007603005, that can be installed up to 400 ft. from the
heater using 20 gauge (minimum) control wire. The temperature remote shall provide diagnostic information, fault history, and heater
set temperature. The heater shall operate using 120 V / 60 Hz power source. The indoor heater will incorporate a factory installed
power cord.
The indoor heater shall be vented with 4” diameter Category III vent pipe with a length not to exceed 50 ft. (equivalent), terminating
horizontally or vertically. The indoor heater can be direct vented with optional direct vent conversion kit, 9007667005, using 3”
diameter air intake pipe. The intake pipe may use material such as PVC, ABS, aluminum, or Category III pipe and cannot exceed 50 ft.
(equivalent) length. The outdoor heater shall be constructed with an integral exhaust vent on the front of the heater.
The water heater shall use a commercial grade copper alloy, fin tube heat exchanger with quick release brass or bronze waterways.
The heater shall be controlled by an onboard solid-state printed circuit board which uses the following factory installed components:
thermistors to monitor inlet and outlet water temperature; a flow sensor to measure flow rate; a flame sensor to monitor combustion;
an Air-Fuel Ratio Rod to measure and adjust operation in order to maintain optimal combustion efficiency. The heater also consists of
inline fusing and surge absorbers for electrical surge protection, an electronic spark igniter, aluminized stainless steel burners, a hi-limit
temperature switch, modulating gas valve, an overheat cutoff fuse, ceramic heating blocks to protect the heat exchanger and water
piping. The indoor heater shall incorporate auto-fire system for additional freeze protection.
The heater can manifold to Easy-Link up to 4 heaters to provide additional capacity. The Easy-Link controls shall be built onto the
onboard solid-state printed circuit board and does not require external controls. The linking control wire shall be supplied with the
heater. The Easy-Link control shall modulate the system for the most efficient performance. The Easy-Link control shall rotate the
priority heater every 12 hours of operation time or 100 starts for balanced duty/cycle operation.
The heater shall be design certified by CSA according to ANSI Z21.10.3, approved for sale in the United States, have a minimum
energy factor of 0.82, meets the energy efficiency requirements of the U. S. Department of Energy and ASHRAE 90.1, complies with
Low NOx emissions of 40 ng/J or 55 ppm, and shall be certified by NSF to NSF/ANSI 5 Standard.
©2015 Takagi www.takagi.com
Page 4 of 4
TRGSS01613