Takagi T-K3 User manual

T-K3 Service Manual
Ver. 1.05
1
CONFI DENTI AL
T-K3 Instantaneous Water Heater
Service Manual
TAKAGI Industrial Co. USA Inc.
5 Whatney
Irvine, CA 92618
Toll Free: [phone] USA
Toll Free: [phone] CANADA

T-K3 Service Manual
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CONFI DENTI AL
Table of Contents
1. Specifications of the T-K3, T-K3-OS, and T-K3-SP……………..………………………… 3
2. Exterior view ……………………...…….…………………………………………………….. 4
3. Interior view …………………………….…………………………………………………….. 5
4. List of main components in the interior view …….………………………………………… 6
5. Schematic diagram………………………………………………………………………….. 7
6. Wiring diagram………………………………………………………………………………. 8
7. Wiring diagram checkpoints for diagnosis………………………..………………….….… 9
8. Resistance values of the temperature ther mistors…………..…………………………… 10
9. Operational flow chart……………………………………………………………………… 11
10. Component specifications………………...………………………………………………… 12
11. Fault Analysis & Specifications……………………………………………………………... 32
12. Controls and settings………………………………………………………………………… 40
13. Components diagrams……………………………………………………………….......... 65
14. Parts list……………………………………………………………………………………….. 68
15. Revisions……………………………………………………...…………………………….. 70

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CONFI DENTIAL
1. Specifications of the T-K3, T-K3-OS, and T-K3-SP
Model T-K3 T-K3-OS T-K3-SP
Dimensions H20.5" ×W13.8"×D8.5" H20.5" ×W13.8"×D8.5" H20.5"×W13.8"×D8.5"
Weight 40lbs.
Max 199,000 190,000
INPUT
BTU/h Min 11,000
Combustion
System Pow er vent
Ins tal latio n Indoor, Outdoor,
& Direct-vent Outdoor Indoor & Outdoor
Fan motor PWM turbo fan PWM fan PWM turbo fan
Max LP 4.4” WC
Natural 2.5” W.C
LP 3.1” WC
Natural 2.8” W.C
LP 4.1” WC
Natural 2.4” WC
Combustion
Man if old
Pressure Min LP 0.7” WC
Natural 0.4” WC
LP 0.8” WC
Natural 0.4” WC
LP 0.8” WC
Natural 0.4” WC
Flow rate 0.5 GPM to 7.0 GPM
Available set
temperatures
99ºF ~ 185ºF
default: 122º F
99ºF ~ 167ºF
Default: 122º F
Temperature
dipsw itch settings
104ºF, 113ºF, 122ºF,
131ºF, 140ºF, 158ºF,
176ºF, 185ºF
113ºF, 122ºF, 140ºF, 167ºF
Bypass valve Yes N / A
Water control
Ther misters 3 thermisters
(In,Out,Mixing) 2 thermisters (In,Out)
Remote controller
mod el
TM-RE10
TM-RE30 TK- RE02
PCB model T-K3 T-K3 OS/SP
Ind ic at or s “Burning” LED &
7-SEG L ED “Burning” LED
Operation
Pow er supply
control
GFI ( Including surge
absorber) Surge absorber & Pow er switch
Freeze protection Ceramic heaters and
Auto-firing system Ceramic heaters
Self-combustion
improvement Air-Fuel Ratio Detection System
Features
Easy-Link system Yes N / A

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CONFI DENTIAL
2. Exterior view
Top view Bottom view
Side view
Front view
5-1/4"(132.9mm) 4-7/ 8"(124 .3mm)
3-1 /4"(84 mm)
5-3/ 8"(13 6.1mm)
2 -3/4"( 72mm)
6-1/2 "(164.4mm)
3-3 /4"(96 .5mm)
1-3/8"(36mm)
1-1/ 2"(37.8mm)
3-5/ 8"(93.3mm)
4- 1/2"( 114.2m m)
20-1/4"(520m m)
13-3/4"(350mm)
1-1/2"(37.8mm)
1-3/4(45mm)1-3/4"(45mm)
10"(2 54mm)
21-3/8"(544mm )
4"( 101.6mm)
1-3/8"(36mm) 120V
4-7/8"(124.3mm) GAS
1-7/8"(47mm)
3-1/4"(84mm) COLD
5-1/4"(132.9mm) HOT
4-1/2"(114.2mm)
19-3/8"(492.7mm)
1"(26.3mm)
2-3/4"(72mm) COL D
3-3/4"(96.5mm) 120V
5-3/8"(136.1mm) GAS
6-1/2"(164.4mm) HOT
9-1/2"(241.3mm)
1-5/8"(42.5mm)

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CONFI DENTIAL
3. Interior view
4. List of main components in t he interior view
No. Des c r iption T- K 3
Par t #
Ta ka g i
Par t #
Common parts
For other units
1 Case assembly 001 EKK1D SP
2 Combustion chamber 102 EKK1Y SP
3 Gas valve w ith Proportional
valve 105 EKK1W OS, SP
4 Computer board 701 EKK1L
5 Igniter 704 EKN74 TKJr, TK1S, TH1, OS, SP
1
2
3
4
5
6
78
9
10
11
12
13
1516
17
18
19
20
21
21
22
23
24
25
14
27
28
29
30
26

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CONFI DENTIAL
4. List of main components in the internal view (cont’d)
No. Des c r iption T- K 3
Par t #
Ta ka g i
Par t #
Common parts
with other models
6 Transformer 702 EKH09 TH1, OS, SP
7 Water inlet 404 EKK1U OS, SP
8 Water outlet 405 EKK1V OS, SP
9 Mixing ther mistor 408 EKK1A
10 In let ther mistor 406 EKK38
11 Outlet t her mistor 407 EKK2T
12 Overheat cut-off fuse 411 EKK0S
13 Burner assembly (Burners) 101 EKK1N OS, SP
14 Hi-limit sw itch 409 EKN34 TKJr, TK1S, TH1, OS, SP
15 Fan motor 104 EKK25 SP
16 Freeze protection ther mostat 705 EKJ59 TK2, TK1S, OS, SP
17 Flow sensor 402 EKK0T
18 Heat exchanger 401 EKK1X SP
19 Gas inlet 108 EKK1E OS, SP
20 Exhaust 401 EKK1X
21 Heater 412 EKK2R OS, SP
22 Flow adjustment valve 402 EKK0T
23 GFI 703 EKN73 TK1S, TKJr, TH1
24 Manifold 103
EKK1T(NA)
EKK1S(L P) OS, S P
25 Outlet drain plug 419 EKK2E OS, SP
26 Air-fuel ratio rod (AFR rod) 716 EKK0E OS, SP
27 Flame rod 716 EKK0E OS, SP
28 Igniter rod 107 EKK0F OS, SP
29 Bypass valve 403 EKK0U
30 Inlet drain plug 416 EKK2B OS, SP

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CONFI DENTIAL
5. Schematic diagram
1. When a hot w ater tap is opened, cold w ater enters the T-K3 w ater heater.
2. The w ater flow sensor detects this w ater flow and sends this information to computer.
3. The computer initiates fan motor and sends signal to igniter to create ignition spark.
4. The main, proportional, and solenoid gas valves open to allow gas input.
5. The gas ignites and flames appear inside the burner chamber.
6. Water circulates through the heat exchanger and is heated up to the set temperature.
7. Using ther mistors to measure temperatures, the computer modulates the gas and w ater
valves to ensure proper output w ater temperatures.
8. When the tap is closed, the T-K3 w ater heater shuts dow n.
H
O
T
C
O
L
D
G
A
S
PCB
Hi-limit SW
Inlet drain
plug filter
Mixing
Thermistor
Drain plug
Main gas valve
Gas solnoid valve 1
Fan motor
Flame rod
Igniter rod
Igniter
O.H.C.F
Heater
Flow adjustment valve
w/ Flow sensor
Gas proportional valve
Gas solenoid valve 3
Air-fu el ratio rod
Gas solenoid valve 2
Outlet
Thermistor
Bypass valve
Inlet
Thermistor Transformer

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CONFI DENTIAL
6. Wiring diagram
Propor-
tional
Valve
3
9
53
73
GFI
G
BK
W
AC120V
Trans-
former
3A
G
Ground
IG
Elect rod
Heater
Freeze
protection
thermostat
Heater
Ground
BK
BK
MV
SV3
SV2
SV1
LB
G
O
R
O.H.C.F
Hi-
limit
switch
BL
BL BL
BL
BL
BL
BL
W
YBL
O
R
FM
W White
R Red
BK Black
P Purple
LB Light blue
BL Blue
G Green
Y Yellow
O Orange
BR Brown
SLAVE IN
BKW
R
BK
WR
W
R
R
Flow
Sensor
W
Bypass
Valve
Flame rod
Ground
AFR rod
Y
G
O
Inlet
thermistor
Outlet
thermistor
Mixing
thermistor
Remote
Controller
Pump MASTER
SLAVE OUT
BK
W
BK W
654321
BK
BK
BK
BK
BK
BK
BK
BK
W
Flow
Adjust
ment
Valve
RR
RR
BKBK
BKBK
Multi-system
On line lamp
7 Seg LED
33
7
7
OFF
1234 56
OFF
PP
PP
BRBR
BRBR
MAX button
MIN button
Increase button
Decrease button
Burning lamp
Dip switch
Error call button
BKBK
WW
A1
A
B1
B2
C1
C2
C
D1
D2
E1
E2
E3
F
G
H1
H2
I
J1
J2
K
A2

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CONFI DENTIAL
7. Wiring diagram check points for diagnosis
Check-
point
Part and Description Color of wires Normal range
A, A1 100V Power supply Brown – Brown (A1)
White – Black (A)
AC 90～11 0 V
A2 120V Power supply Black - White AC 108～132V
B1 Heater Black - Black AC 90～11 0V
B2 Igniter Purple - Purple AC 90～11 0V
Light blue - blue at COM DC 78~100V(in operation) / 0.9~1.3kΩ
Green - blue at COM DC 78~100V(in operation) / 1.3~1.9kΩ
Orange - blue at COM DC 78~100V(in operation) / 1.3~1.9kΩ
C Gas valves
Red - blue at COM DC 78~100V(in operation) / 0.9~1.7kΩ
C Proportional Valve White - red at COM DC 1~10V(in operation) / 30~51Ω
C1 Hi-limit switch Blue - Blue Less than DC 1V and less than 1.3Ω
C2 Overheat cutoff fuse Blue - Blue Less than DC 1V and less than 1.3Ω
D1 Black - White DC 15V (during Easy-Link operation)
D2
Easy link connectors
Black - White DC 15V
E1 Mixing thermistor Black - Black
E2 Outlet thermistor Black - Black
E3 Inlet thermistor Black - Black
See table on p. 10
F Remote controller * DC 11～25V
Red - Blue DC 110～160V
Yellow - Blue DC 13～17V
Orange - Blue DC 2～6.5V
G Fan motor
White - Blue See the “A
H1 Gas proportional valve White - red DC 1～10V and 30～50 Ω
Red - Black DC 4～5.5V
H2 Flow sensor
White - Black DC 1～4V (1080pulse / min)
Air-fuel ratio flame rod Yellow - AFR rod More than 1μA (during burning)
I
Flame rod Orange - Flame rod More than 1μA (during burning)
J1 Flow adjustment valve Red - Black DC 7～16V and 0.09～0.2kΩ
J2 Bypass valve Red - Black DC 7～16V and 0.09～0.2kΩ
K Pump connector port White - Black Less than 1.3Ω

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CONFI DENTIAL
8. Resistance values of the temperature thermistors
Resistance values at different temperatures
ºF 32 41 50 59 68 77 86 95 104 113
ºC 0 5 10 15 20 25 30 35 40 45
Resistance kΩ23.76 19.08 15.43 12.56 10.28 8.47 7.02 5.85 4.90 4.12
Temperature ºF 122 131 140 149 158 167 176 185 194 203 212
ºC 50 55 60 65 70 75 80 85 90 95 100
Resistance kΩ3.49 2.96 2.53 2.16 1.86 1.60 1.39 1.21 1.05 0.92 0.81
Temperature(ºF) vs. Resistance(kΩ)
Temperature(℃)vs. Resistance(kΩ)
Temperature
0.00
5.00
10.00
15.00
20.00
25.00
20 40 60 80 100 120 140 1 60 180 200 220
Temperature (ºF)
Resisitance(kΩ)
0.00
5.00
10.00
15.00
20.00
25.00
0 102030405060708090100
Temperature (ºC)
Resisitance (kΩ)

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CONFI DENTIAL
9. Operational flow chart
Power supply ON
Opeartion SW ON
OPEN FAV BV
Pre-check
NORMAL?
OPEN the tap
Flow Sensor
Above 0.5GPM?
FM speed
(Below
1,000rpm?)
Start FM
Pseudo-flame
Below
DC0.15
ƒÊ A?
Iginiter ON
Hi-limit
Normal?
OHCF
Normal?
MV ON
SV1 ON
GPV ON
Detect Flame
Above
DC1.0uA?
Burning lamp ON
Iginiter OFF
Proportional control
Change over
point?
SV2 SV3 ON
Above water
heat capability?
FAV OPEN
Safety devise
work?
FAV close
SV2 SV3 OFF
Miss select
gas type
InTH failure
PCB failure
SV circuit failure
031 blink
321 blink
701 blink
511 blink
611 blink
Stop FM
721 blinkPeseudo-flame
Igniter OFF
Retry ignite
Success?
OuTH OPEN
or SH ORT
A bnormal
F M Speed
MV OFF
SV1 OFF
GPV OFF
SV1, SV2, SV3 OFF
STOP FM
CLOSE the tap
Flow sensor OFF
Remove cause
Opeartion lamp OFF
OPEARTION OFF
YES
NO
YES
NO
NO
YES
YES
NO
(20sec later)
YES
NO
NO
YES
YES
NO
YES
NO
(5sec later)
(3sec later)
YES
YES
NO
YES
NO
(20sec later)
YES
NO
NO
NO
‡F
YES
FAV ; Flow Adjustment Valve
B V ; Bypass Valve
F M ; Fan Motor
OHCF; Over Heat Cut-off Fuse
M V ; Main gas Valve
SV1 ; Solenoid Valve 1
SV2 ; Solenoid Valve 2
SV3 ; Solenoid Valve 3
GPV ; Gas Proportional Valve
InTH; Inlet thermistor
OuTH; Outlet thermistor
MiTH; Mixing thermistor
PCB ; Print Circuit board
(Computer board)
AFR ; Air Fuel Ratio
FM speed
(Above
1,000rpm?)
Above
Max flow rate
ristriction?
111 blink
121 blink
6 11 blink311 blink
OuTH failure 311 blink
MiTH failure 331 blink
Flame rod
failure
Melt OHCF
Above 363
‹ F
AFR rod failure Abnorm al
AFR
121 blink121 blin k991 blink391 blink
BV action
32 1 blink
InT H OPEN
or SHORT
331 blink
MiTH OPE N
or SHORT

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CONFI DENTIAL
10. Component specifications
1. Burners
P.13
2. Manifold
P.14
3. Fan motor
P.15
4. G a s va l ve a sse m b l y
P.16
5. Flame rod
P.17
6. AFR rod
P.18
7. Heat exchanger
P.19
8. Flow adjustment valve
P.20
9. Flow sensor
P.21
10. Bypass valve
P.22
11. Thermistors
P.23
12. Hi-limit switch
P.24
13. Overheat cutoff fuse
P.25
14. Heaters
P.26
15. Computer board
P.27
16. Transformer
P.28
17. GFI
P.29
18. Igniter
P.30
19. Freeze protection
thermostat
P.31
AFR Rod
Fl ame rod
AFR Rod
Fl ame rod

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CONFI DENTIAL
10-1. Burners
T-K3 Part # #101 Takagi Part # EKK1 N Checkpoint N/A
Function
F ailu re even ts
Effects on the T-K3
if burners fails
Error codes when the
burners fail
D iagno stic
Color/Number of
wires
N/A
Visual inspection: excessive dust deposit on the burner surface and/or unstable
flam e conditions during operation.
There are 2 types of burners in the T-K3: the gas-rich burner stabilizes the flames
within the combustion chamber and the air-rich burner produces more heat in the
combustion chamber. The burners facilitate the air/gas mixture necessary to
pr od uce the proper heat durin g the com bustion rea ction.
1. Unable to initialize/sustain combustion
2. Dust or soot deposit on the burner surface.
3. Cracks on the burners. 4. Gas leakage from burners
1. An unexp ected co mbustion.
2. Unstabl e flame co nd itions an d/or flame loss.
3. Ignition failure.
111 121
3-1/8 " (80mm)
5-5/8" (143.2mm)
6-3/4" (170mm)
3 /8" (11.0mm)
Si xt ee n T- K3 B ur ne rs
T- K3 B ur ne r

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CONFI DENTIAL
10-2. Gas manifold
T-K3 Part # #103 Takagi Part # EKK1F Checkpoint N/A
Function
Failure events
Effects on the T-K3
if the manifold fails.
Error codes when
the manifold fails.
D iagno stic
Color/Number of
wires Blue -Red DC 78~100V / 0.9~1.7kΩ
1. Visual inspection: Excessive dust deposit around the nozzles or cracks on the
manifold.
2. Check voltages and resistance: proper range of values shown below.
1. The manifold distributes gas from the gas valves to the burners. The manifold
has two typ es of the nozzles: one type fo r gas-rich burners (16 no zzl es) and the
oth er for air-ri ch burners (15 nozzles)
2. There are 3 zones within the manifold, to ensure efficient combustion operation.
1. Dust deposit on the manifold. 2. Gas leakage from a failed manifold.
3. Ignition failure. 4. Imperfect combustion.
1 . Th e burner s ca nn ot re ceive pro per ga s flo w fr om th e ma nifo ld, which can ca use
poor combustion in the combustion chamber. In this case, the AFR rod will detect
an improper flame condition and computer will take safety measures.
2 . Gas le aka ge fr om th e ma nifo ld.
111 121
9 -1/ 8" (23 2mm)
6-7/ 8" ( 175m m)
Nozzles for gas-rich burners
Nozzles for air-rich burners

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CONFI DENTIAL
10-3. Fan motor
T-K3 Part # #104 Takagi Part # EKK25 C heckpo int G
Function
F ailu re even ts
Effects on the T-K3
if fan motor fails
Error codes when
the fan motor fails.
D iagno stic
Red-Blue
Yellow-Blue
Orange-Blue
White-Blue
Color/Number of
wires
To provide com bustion air into the burn er ch am ber a nd to exhaust flue gas.
1. Visual inspection: connection/breakage of wires or dust (causing electrical
shorta ge )
2. Voltage check: proper range of voltages shown below.
1. Fa n speed fail ure , cau sing abnormal so un ds with o r witho ut co mbustion in th e
operation.
2. Unexpected working caused by the connectors of the fan motor getting wet.
3. Drops out from the bottom of the combustion chamber
1. T-K3 does not function properly
2. Failure to ignite or abnormal ignition
3. Unstable combustion conditions
DC 110~160V (Input)
D C 13~1 7V (Inp ut)
611
DC 2.0~6.5V (Input)
Verify the fan motor speed using the Diagnostics Mode of the
TM-RE10 temperature remote controller. See Section 12-1 for
details.
ASAHI 6-1/2" (165.5mm)
3-3/ 4"(95.75mm)
Freez e protect ion thermo stat
Fan da mper

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CONFI DENTIAL
10-4. Gas valve assembly
T-K3 Part # #105 Takagi Part # EKK1W Checkpoint C,H1
F ailu re even ts
Effects on the T-K3
if valves fails.
Error codes when
the valves fail.
111 121 510 701 711
D iagno stic
DC 78~100V / 0.9~1.7KΩ
DC 78~100V / 0.9~1.3KΩ
DC 78~100V / 1.3~1.9KΩ
DC 78~100V / 1.3~1.9KΩ
D C 1 ~15 V / 20 ~40Ω
Blue -Green
1. Visual inspection: connection/breakage of wires.
2. Listen for "clunk" sounds from the gas valves opening right after fan motor
initiates.
3. Check voltages and resistance of c oils; pr oper r ange of values sh own be low.
Blue -light blue
Blue -Orange
1. Gas leak from the unit.
2. Excess carbon monoxide emissions.
3. Lack of wa ter tem perature control .
4. No flames
Blue -Red
Modulates the gas flow from the gas inlet (proportional gas valve)
Function
Opens and closes the gas pathways of the T-K3 (main and solenoid gas valves)
1. Gas leak from the valves.
2. Unable to open/close (mai n and so len oi d ga s valves)
3. Unable to modulate the gas flow (proportional gas valve)
Color/Number of
wires
White - Red (Proportional Valve
)
3-5/ 8" (91 .5m m)
1-3 /8 " (34mm)
2-5/8" (67mm)
Proportional valve
Main gas v al ve
Gas
valve
4-1/4" ( 10 8m m) 7/8" (22.2mm)
4-5/8" ( 119 mm )
Solenoid valve
Proportional Valve

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CONFI DENTIAL
10-5. Flame rod
T-K3 Part # #716 Takagi Part # EKK0E Checkpoint I
Function
Failure event
Effects on the T-K3
if flame rod fails
Error codes when
the flame rod fails.
111 121 721
D iagno stic
The flame rod is assembled with the AFR rod.
Orang e(1 7) - Flam e r od
between the flame rod an d the
co mp ute r bo ar d
Color/Number of
wires
1. Visual inspection: connection/breakage of wires or soot buildup on rod.
2. Check amperes: proper range of values shown below.
To detect flames whil e unit i s i n oper atio n.
1 Unable to detect flames when flames actually do occur
2. Detecting a false flam e when n o flames actually occur
1. The T-K3 stops operating. The "111" and/or "121" error code(s) will display
2. The T-K3 will not initiate the ignition proc ess. The "721" error code will display
(during combustion) 40KHz~60KHz Or ange (1 7) - G r een(18)
(during combustion) 1μA or more
1-3/8" (35mm)
5/8" (15mm)
7/8" (24mm) 3-1/2" (88.6mm)
2-1/4" (58.6mm)
AFR Ro d
Flame r od
Leads to computer board
Detecting elements (flame and AFR

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CONFI DENTIAL
10-6. AFR rod
T-K3 Part # #716 Takagi Part # EKK0E Checkpoint I
Functions
Failure event
Effects on the T-K3
if the AFR rod fails
Error codes when
the AFR rod fails.
101 991 391
D iagno stic
The AFR rod is assembled with the flame rod.
(during operation) 1μA or more
-Checks flame conditions during combustion.
- Wh en AFR r od d etects un exp ected flam e con dit io ns, the T- K3 's co mputer mak es
adjustments in the fan motor speed to compensate.
1. Visual inspection: connection/braking of wires, soot on it.
2. Check voltages: proper range of values are shown below.
Color/Number of
wires
1. Unable to detect flames when flames actually do occur
2. Detecting a false fl am e when no fl am es actually occur
1. Th e T- K3 sto ps oper ating. Th e "1 11" a nd /or "1 21 " er ror code(s) wi ll display
2. The T-K3 will not initiate the ignition process. The "721" error code will display
3. The fan motor spe ed cannot be modulated prope rly under ab no rmal flam e
conditions, which can result in excessive CO emission.
Yellow(8) - Green (18)
(during operation) 40KHz~60KHz
Yellow (8) - AFR rod:
between the AFR r od and the
computer boa rd
1-3/8" (35mm)
5/8" (15mm)
7/8" (24mm) 3-1/2" (88.6mm)
2-1/4" (58.6mm)
AFR Rod
Flame rod
Leads to computer board
Detecting elements (AFR and flame rods)

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CONFI DENTIAL
10-7. Heat exchanger
T-K3 Part # #401 Takagi Part # EKK1X Checkpoint N/A
Function
Failure event
Effects on the T-K3
i f the heat
exch an ge r fails .
Error codes when the
heat exchanger fails.
D iagno stic
Color/Number of wires N/A
1. Visual inspecti on: soot deposits, cr ack s on the he at exchanger walls, and/o r
water leakage from the heat exchanger.
2 . In the eve nt of ab norm al so unds d ur ing com bu stion:
A. Inspect for soot buildup inside the heat exchanger.
B. Ins pect fo r scale buildup i nside the he at exch ang er pipes. Scal e build up
obstructs proper heat transfer to the water, thereby overheating the heat
exchanger and causing damage.
Absorb heat from combustion and transfer it to water through the heat
exchanger pipes.
1. Clogged heat exchanger fins and/or cracks on the heat exchanger walls.
2. Leaking exhaust gas.
3. Improper heat transfer can cause the water in heat exchanger to boil.
1. Water leakage from the heat exchanger
2. Exhaust gas leakage (if this occurs, an overheat cutoff fuse is in place to
detect this event and immediately stop the T-K3 from operating)
3. Abnormal sounds during combustion
N/A
14-1/4" (361.3mm)
11-3/4" (297.2mm)
20-5/8" (522.5mm)
Heat exchange r
Water pipes
Exhaust chamber

T-K3 Service Manual
Ver. 1.05
20
CONFI DENTIAL
10-8. Flow adjustment valve
T-K3 Part # #402 Takagi Part # EKK0T Checkpoint J1
Function
F ailu re even t
Effects on the T-K3
if flow adjustment
valve
fails
Error codes when
F low Adjustment
Valve fails.
D iagno stic
Color/Number of
wires Black-Red
The flow adjustment valve is assembled with the flow sensor.
1. Visual inspection: connection/breakage of wires, motor drive locked due to
scal e build up , and /or water leak age.
2. Check voltages and resistan ce; prope r range of val ue s show n be low .
DC7 ~16V and 0.09~0.2kΩ
Controls water flow to properly control the output hot water temperaturet.
1. Water leakage from valve.
2. The valve cannot modulate or make open/close positions.
1. W ater leaka ge fr om failed val ve can da mage other T-K3 components.
2. Te mp er atur e fluctuatio ns in the h ot wate r ou tp ut.
3. Within a multi-unit Easy-Link system, the "651" error code can occur.
651 (only within multi-unit Easy-Link systems)
Flow adjustment
valve
+ -
-+
132
Open
(Re d) ３
Close
(Bl ack) １
M
No. ３
No. 2
No. １
Flow
adjustment
valve
>PPE-GF<
1-7/8" (47mm)
3-3/8" (84.4mm)
2- 5/ 8" (6 7.5mm )
IN
OUT
Flow
adjustment
valve
Flow sensor
Flow
adjustment
valve
Flow sensor
OUT
IN