A.O. Smith T-M50 ASME User manual

A.O. Smith T-M50 ASME User manual
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
T-M32 / T-M32 ASME
On-demand Water Heater
Service manual
T-M32
A.O. Smith Water Products Company
500 Tennessee Waltz Parkway
Ashland City, TN 37015
Toll Free: 1-877-737-2840
1
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
Table of Contents
1. Specifications………………………………………...…...………….……………………...…………………………
3
2. Exterior view……………………………………………………………………………………………………………..
4
3. Interior view….…………………………………………………………………………………………………………..
4. List of main components in the interior view………………………………….………………………….
5
6
5. Schematic diagram…………………………………………………………………………………………..………..
8
6. Wiring diagram…………………….………………………………………………………………………..………….
7. Wiring diagram checkpoints for diagnosis……………………………………………………………….…
9
10
8. Resistance values of the temperature thermistors……………..………………………………………
12
9. Operational flow chart..……………………………………………………………………………………………..
10. Component specifications………………………………………………………………………………………….
13
14
11. Fault Analysis & Specifications……………………………………………………………........................
35
12. Controls and settings………………………………………………………………………………………………….
46
13. Components diagrams………………………………………………………………..................................
75
14. Parts list……………………………………………………………………………………………………………………..
78
15. Revisions…...................................…………………………...………………………………..………………… 82
2
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
1. Specifications
Unit Model
T-M32 / T-M32 ASME
Unit dimensions
H 23.6"×W 18.5"×D 8.9"
Weight
59 lbs.
Combustion
INPUT
BTU/h
Water control
Operation
240,000
Min
24,000
Combustion System
Power vent
Installation
Indoor, Outdoor, Direct vent
Fan motor
PWM Turbo fan
Manifold
Pressure*
Future
Max
LP 3.4” WC
Natural 2.3”W.C
LP 0.7 WC
Natural 0.5” WC
Max
Min
Flow rate
0.5 to 9.0 GPM
Available set temp.
100°F to 185°F
default set 120 °F
Temperature
dipswitch setting
Bypass valve
100°F, 115°F, 120°F, 135°F, 145°F, 155°F, 165°F, 185°F
Yes
Thermistors
3 thermistors (In, Out, Mixing)
Available remote
controller
TM-RE30
PCB Model
T-M32 (Part # EM376)
Indicators
Red LED on PCB during operation & 7-seg LED
Power supply
control
GFI & Surge absorber
Freeze protection
Ceramic heaters and Auto- FM system
Self-combustion
improvement
Air Fuel Ratio detection system
Easy-link system
Yes
Multi-unit system
Yes
*The manifold pressure measurement is base on conditions without front cover.
3
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
2. Exterior view
Side view
Front view
18-1/2" (470mm)
8-7/8" (226mm)
15-3/4" (399mm)
7" (179mm)
101mm)
2 3- 5 / 8 " ( 6 0 0 m m )
4" (
2 4 - 5 /8 "( 62 6 m m )
4 -1 / 2 " (1 1 4 m m )
1 - 1 / 8 " ( 2 7 .8 m m )
C O L D 3 - 1 / 8 " ( 8 0 .8 m m )
4 - 5 / 8 " ( 1 1 8 .3 m m )
5 - 1 / 2 "( 1 4 2 m m )
6 - 1 /4 " ( 1 59 mm )
Bottom view
4 - 5 / 8 "( 1 1 8 .3 m m )
HOT
HOT
120
VAC
5- 7/ 8 "(1 4 9 m m )
1 - 5/ 8" ( 42 m m)
GAS
5 - 7/ 8 "(1 47 .9 mm )
COLD
1 - 5/ 8"(4 0.9 m m)
CO LD
VAC
120
5 - 1 / 2 "( 1 4 2m m )
5 - 3 / 4 "( 1 4 7 m m )
5 - 1/ 2 "(1 4 1 .6 m m )
Top view
4
6 - 1 / 4"( 1 59 m m )
GAS
GAS
VAC
3 - 1 / 8 "( 8 0 .8 m m )
HOT
1 20
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
3. Interior view
17
1
13
11
10
19
5
12
24
20
16
25
23
2
26
4
15
28
21
9
3
8
7
22
5
14
6
27
18
29
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
4. List of main components in the interior view
Items# in
No.
Description
components
diagram
1
2
3
Case assembly
Manifold assembly with gas
valve assembly
Computer board
Takagi
Common parts
Part #
For other models
001
EM389
120
EM440
(LP model)
EM441
(NA model)
701
EM376
T-K3, T-K3-SP/OS,
4
Igniter
125
EKN74
T-H2-DV/OS, T-KJr2-IN/OS,
T-K4-IN/OS, T-D2-IN/OS,
T-M50
5
Transformer
702
EM454
6
Water inlet
411
EM404
7
Water outlet
435
EKJ02
8
Mixing thermistor
418
EX00H
9
Inlet thermistor
422
EKK38
10
Output thermistor
433
EKK2T
11
Overheat cut-off fuse
403
EM387
12
Burner assembly (Burners)
101
EM410
T-H2-DV/OS
T-H2-DV/OS
T-K3, T-K3-Pro, T-H2-DV/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-H2-DV/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS,
13
Hi-limit switch
432
EKN34
T-H2-DV/OS, T-D2-IN/OS,
T-M50
T-K3, T-K3-Pro, T-K3-SP,
14
Fan motor
115
EKK25
T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
15
Freeze protection
thermostat
T-K3, T-K3-Pro, T-K3-SP,
117
EKJ59
T-KJr2-IN/OS, T-K4-IN/OS,
T-D2-IN/OS
6
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
Items# in
No.
Description
components
diagram
16
17
Flow sensor
Heat exchanger
429
Takagi
Common parts
Part #
For other models
EKH33
T-H2-DV/OS, T-M50
EM415
(Regular model)
EM45C
(ASME model)
210
211
18
Gas inlet
123
EM442
19
Heater
410
EX002
T-H2-DV/OS, T-M50
20
Water control valve
423
EKH32
T-H2-DV/OS, T-M50
21
GFI
712
EM207
T-M50
22
Outlet drain plug
416
EK239
T-H2-DV/OS
T-K3, T-K3-Pro, T-K3-SP/OS,
23
Air-fuel ratio rod (AFR rod)
106
EKK0E
T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS,
24
Flame rod
106
EKK0E
T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS,
25
Igniter rod
108
EKK0F
T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
26
Surge box
715
EM385
T-M50
27
Inlet drain plug (water filter)
408
EX006
T-H2-DV/OS, T-M50
28
Manifold port
N/A
N/A
29
Gas inlet port
N/A
N/A
7
CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
5. Schematic diagram
Exhaust
Heat Exchanger
Air-fuel ratio rod
Flame rod
Hi-limit switch
Output Thermistor
O.H.C.F
Igniter rod
Fan motor
Burner
Igniter
Water control
valve
Gas solenoid valve 3
PCB
Gas solenoid valve 1
GFI
Gas solenoid valve 2
Transformer
Main gas valve
Flow sensor
Gas proportional valve
Surge box
Mixing Thermistor
Inlet
A120
C 1VAC
20V
Hot water
Thermistor
Gas
Cold water
1. When a hot water tap is opened, cold water enters the T-M32.
2. The water flow sensor detects this water 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 thermistors to measure temperatures, the computer modulates the gas and water valves to
ensure proper output water temperatures.
8. When the tap is closed, the T-M32 shuts down.
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CONFIDENTIAL
T-M32 / T-M32 ASME Service manual
Ver. 1.03
6. Wiring diagram
BK: BLACK
P: PURPLE
LB:LIGHT BLUE
G: GREEN
BL: BLUE
Y: YELLOW
W: WHITE
Water
Control
valve
R
R: RED
BL
BK
W
G
Y
O
R
BR
BK
W
G
Y
B u r ni n g
lamp
button
D ec r e a se
button
E r r or
c a ll
BK
Inlet
thermistor
BK
Output
thermistor
BK
SV2
SV1
SV3
MV
R
C
C
C
C
BK
BK
C2 A
C1
BL
BL
K
GFI
Hil imi t
s wit ch
BL
BL
BR
BR
BR
BR
9
BK
W
Transformer
A1
W
W
Parent
O
O
3
P
4
P
Flame rod
L
Ground
2
Ground
G
Pump
BL
BL
Air-fuel
ratio rod
B
W
1
R emot e
c ontr ol ler
BK
I
O
R
R
TM-RE30
W
O
W G
O.H.C.F
BK
D2
G
R
LB
BL
BL
Flow
Sensor
GY
Y
G
BL
BK
W
R
BK
F
R i gh t b an k o f
d i ps wi t ch es
E1
E3
E2
BK
W
GY
button
Mixing
thermistor
W
WR
123456 78
I nc r e a se
OFF
button
R
Gas
Proportional
Valve
D1
12345678
M IN
OFF
7 Seg LED
Left bank of
d i p sw i t c h e s
M AX b u t t o n
BR:BROWN
GY:GRAY
H1
J
H2
Number display button
O: ORANGE
O
Y
BL
R
P
P
W
P
P
FM
Igniter rod
IG
Heater
BK
Heater
BK
Heater
A2
A3
Heater
BK
W
Surge
box
BK
W
Thermostat
120 VAC
G
Ground
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
7. Wiring diagram check points for diagnosis
Checkpoint
Parts and Description
Color of wires
White – Black (A)
Normal Range
A, A1
100 V Power supply
A2,A3
120 V Power supply
Black - White
108 to 132 VAC
B
Igniter
Purple – Purple
90 to 110 VAC
Brown – Brown (A1)
Light blue - blue at COM (MV)
Green - blue at COM (SV1)
C
Gas valves
Orange - blue at COM (SV2)
Red - blue at COM (SV3)
90 to 110 VAC
78 to 100 VDC (during operation)
/ 0.9 to 1.3kΩ
78 to 100 VDC (during operation)
/ 1.3 to 1.9kΩ
78 to 100 VDC (during operation)
/ 1.3 to 1.9kΩ
78 to 100 VDC (during operation)
/ 0.9 to 1.7kΩ
C1
Hi-Limit switch
Blue - Blue
Less than 1 VDC and less than 1 Ω
C2
Overheat cutoff fuse
Blue - Blue
Less than 1 VDC and less than 1 Ω
White - White
15 VDC
Red – Red
15 VDC
Blue – Blue
(during Easy-link operation)
Multi-unit link
Purple- Purple
15 VDC
connectors
Orange -Orange
(during Multi-unit operation)
E1
Mixing thermistor
Black - Black
E2
Output thermistor
Black - Black
E3
Inlet thermistor
Black - Black
F
Remote controller
Black - White
11 to 25 VDC
Red - Blue
110 to 160 VDC
Yellow - Blue
13 to 17 VDC
Orange - Blue
2 to 6.5 VDC
D1
D2
G
Easy-link connectors
Fan motor
See table on p.12
1 to 15 VDC (during operation)
H1
Gas proportional valve
White - red
and
20 to 40 Ω
10
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Checkpoint
H2
Parts and Description
Flow sensor
Color of wires
Normal Range
Red - Black
4 to 5.5 VDC
White(+) – Black(GND)
1 to 4 VDC (1,200 Pulse/min)
Yellow – AFR rod
Air-fuel ratio rod
(Between AFR rod and
the computer board)
I
Orange – Flame rod
Flame rod
(Between flame rod and
the computer board)
J
Water control valve
More than 0.5 μA
(during operation)
More than 1 μA
(during operation)
Blue – Brown
13 to 16 VDC
Orange – Brown
ON: 12.5 to 16 VDC
OFF: 0 to 1 VDC
Red – Brown
1 VDC Less ( 0°C position)
K
Pump connector
White - Black
Less than 1.3 Ω
L
Heater
Black – Black
90 to 110 VAC
11
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
8. Resistance values of the temperature thermistors
Resistance values at different temperatures
Temperature
ºF
32
41
50
59
68
77
86
95
104
113
ºC
0
5
10
15
20
25
30
35
40
45
Resistance
kΩ
23.76
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
kΩ
3.49
2.96
2.53
2.16
1.86
1.60
1.39
1.21
1.05
0.92
0.81
Resistance
Temperature / ºF vs Resistance / kΩ
25.00
Resisitance / kΩ
20.00
15.00
10.00
5.00
0.00
20
40
60
80
100
120
140
160
180
200
220
60
70
80
90
100
Temperature / ºF
Temperature / ℃ vs Resistance / kΩ
25.00
Resisitance / kΩ
20.00
15.00
10.00
5.00
0.00
0
10
20
30
40
50
Temperature / ºC
12
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
9. Operational flow chart
Power supply ON
FAV&BV open
Operation SW ON
Remove cause
Opeartion lamp OFF
Pre-check
NORMAL?
YES
NO
Operation stop
Faucet opens
Water Flow
Above 0.5GPM?
NO
YES
BV modulates
Flow&temp
False Dipswitch
settings
031 blink
InTH failure
321 blink
OuTH failure
311 blink
MiTH failure
331 blink
PCB failure
701 blink
MV circuit failure
510 blink
SV circuit failure
551 blink
Fault of Bypass
function in Water
control Valve
661 blink
Fault of Flow
adjustment function
in Water control
Valve
FM speed
(Below
1,000rpm?)
651 blink
NO
Flow sensor OFF
Faucet closes
YES
Fan moter start
operation
611 blink
FM speed
(Above
1,000rpm?)
NO
Fan motor stop
operation
Fan motor
stop operation
(20sec later)
YES
NO
Flame rod
detects Below
DC0.15 A?
YES
False flame
FAV ;
B V ;
F M ;
OHCF;
M V ;
SV1 ;
SV2 ;
SV3 ;
GPV ;
InTH;
OuTH;
MiTH;
PCB ;
Flow Adjustment Valve
Bypass Valve
Fan Motor
Over Heat Cut-off Fuse
Main gas Valve
Solenoid Valve 1 (See the section 6)
Solenoid Valve 2 (See the section 6)
Solenoid Valve 3 (See the section 6)
Gas Proportional Valve
Inlet thermistor
Output thermistor
Mixing thermistor
Print Circuit board
(Computer board)
AFR ; Air Fuel Ratio rod
721 blink
Igniter ON
Hi-limit
Normal?
YES
OHCF
Normal?
NO
YES
111 blink
NO
Reignition
Success?
NO
121 blink
YES
MV ON
SV2 ON
GPV ON
Igniter OFF
MV OFF
SV2 OFF
GPV OFF
SV1 SV3 OFF
Flame rod
NO
detects Above
DC1.0 A?
(5sec later)
YES
Burning lamp ON
Igniter OFF
(3sec later)
Proportional control
BTU
change over
point?
NO
SV1 SV3 OFF
YES
SV1 SV3 ON
NO
Below water
heat capability?
391 blink
991 blink
AFR rod failure
FAV CLOSE
Abnormal
burning
121 blink
121 blink
OHCF melted
(above 430 F)
Flame
blows out
YES
Below
NO
Max flow rate
restriction?
YES
FAV OPEN
311 blink
OuTH OPEN
or SHORT
321 blink
InTH OPEN
or SHORT
Safety devices
YES
sensed
abnormal condition
331 blink
MiTH OPEN
or SHORT
(20sec later)
NO
13
611 blink
Fan motor
fault
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10. Component specifications
10-1. Burners……………………..…………………………………………….………………………....………. 15
10-2. Gas manifold…………….…………………………..…………………………………………………..... 16
10-3. Fan motor……………………………………………………………………….………………………...… 17
10-4. Gas valve assembly……………………………………….……………………………………….…….
18
10-5. Flame rod………………………………………………………….…………………………………………
10-6. AFR rod……………………………………………………………………………..…………………………
19
20
10-7. Heat exchanger…………………………………………………………….....………………….………
21
10-8. Flow sensor…………………………………………………………………………………………………. 22
10-9. Water Control valve………………………………...………………………………………………..… 23
10-10. Thermistors………………………………..……………………………………..………………………… 25
10-11. Hi-limit switch………………………….…………………………………………………………..……… 26
10-12. Overheat cutoff fuse..……………………………………………………………………………..…… 27
10-13. Freeze protection heaters….……….……………………………………………………………….. 28
10-14. Computer board………………………………………………………………………………………….. 29
10-15. Transformer…………………………………………………………….………….……………………….
30
10-16. GFI…………………………………………………………………………………................................ 31
10-17. Igniter………………………………………………………………………………............................. 32
10-18. Freeze protection thermostat…………………………………………………….................... 33
10-19. Surge box……..………………………………………………………………….............................
14
34
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-1. Burners
Unit Part #
#101
AOS Part #
EM410
Checkpoint
N/A
There are 2 types of burners in the water heater: the gas-rich burner
stabilizes the flames within the combustion chamber and the air-rich burner
Function
produces more heat in the combustion chamber. The burners facilitate the
air/gas mixture necessary to produce the proper heat during the combustion
reaction.
1. Unable to initialize/sustain combustion.
2. Dust or soot deposit on the burner surface.
Failure event
3. Cracks of the burners.
4. Gas leakage from the burners.
1. Unexpected combustion.
Effects on the water 2. Unstable flame conditions and/or flame loss.
heater if burners fails
3. Ignition failure.
4. Back-firing.
Error codes when the
101
111
121
991
burners fails
V isual inspection: excessive dust deposit on the burner surface and/or
Diagnostic
unstable flame conditions during operation.
N/A
9 -5 / 8 " ( 24 5 m m)
33T
1 0 - 3 /4 " ( 2 7 3 m m )
5 - 1 / 4 " ( 1 32 m m )
Burner damper (#101 / EM409)
1 - 3/ 4 " (4 4 m m)
7 -1 / 2 " ( 1 9 0 mm )
Color / Number of wires
"3 3T " m a rk
The burner damper is not
included in EM410.
15
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-2. Gas manifold
Unit Part #
#120
AOS Part #
EM440 (LP model)
EM441 (NA model)
Checkpoint
N/A
1. The manifold distributes gas from the gas valves to the burners. The
manifold has two types of the nozzles: one type for gas-rich burners (20
Function
nozzles) and the other for air-rich burners (19 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.
Failure event
3. Ignition failure.
4. Imperfect combustion.
1. The burners cannot receive proper gas flow from the manifold, which can
Effects on the water cause poor combustion in the combustion chamber. In this case, the AFR rod
heater if the manifold will detect an improper flame condition and computer will take safety
fails
measures.
2. Gas leakage from the manifold.
Error codes when the
101
111
121
991
manifold fails
1. Visual inspection: Excessive dust deposit around the nozzles or cracks on
Diagnostic
the manifold.
2. Check voltages and resistance: proper range of values shown below.
Blue-Red
Color / Number of wires
78 to 100 VDC / 0.9 to 1.7 kΩ
Nozzles for gas-rich burners
EM440 (for LP model) and EM441 (for NA
model) is an assembly of the gas manifold
with the gas valve assembly. For safety
reasons, these assemblies should be installed
in the unit as a whole set.
The gas manifold has the “33T” mark on the
manifold plate.
Nozzles for air-rich burners
33 T
"3 3 T " m a r k
7-7/8 " (203 mm)
10-7/ 8" (277 mm)
16
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-3. Fan motor
Unit Part #
#115
AOS Part #
EKK25
Checkpoint
G
To provide combustion air into the combustion chamber and to exhaust
flue gas.
1. Fan speed failure, causing abnormal sounds with or without combustion
during operation.
Failure event
2. Unexpected activation caused by the connectors of the fan motor getting
wet.
3. Disconnects from the bottom of the combustion chamber.
1. The water heater does not function properly
Effects on the water
2. Failure to ignite or abnormal ignition
heater if fan motor fails
3. Unstable combustion conditions
Error codes when the fan
101
111
121
611
991
motor fails
1. V isual inspection: connection / breakage of wires or dust (causing
Diagnostic
electrical shortage)
2. Voltage check: proper range of voltages shown below.
Function
Color / Number of wires
Red-Blue
110 to 160 VDC (Input)
Yellow-Blue
13 to 17 VDC (Input)
Orange-Blue
2.0 to 6.5 VDC (Input)
Verify the fan motor speed using the Diagnostics Mode of
the temperature remote controller. See Section 12-1 for
details.
6 - 1 / 2 " ( 1 6 5 .5 m m )
White-Blue
PWN turbo fan motor
Op en in g
2-1 /8 "(
54 mm )
3 - 3 / 4 "( 9 5 .1 5 m m )
46
1-
The fan damper
is not included in
EKK25.
17
3/
4"
(
46
Fan damper (#116 / EM381)
mm
)
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-4. Gas valve assembly
Unit Part #
Function
#120
AOS Part #
EM440 (LP model)
EM441 (NA model)
Checkpoint
C,H1
Opens and closes the gas pathways of the water heater (main and solenoid
gas valves)
Modulates the gas flow from the gas inlet (proportional gas valve)
1. Gas leak from the valves.
Failure event
2. Unable to open /close (main and solenoid gas valves)
3. Unable to modulate the gas flow (proportional gas valve)
1. Gas leak from the unit.
Effects on the water
2. Excess carbon monoxide emissions. / No flames.
heater if valves fails
3. Lack of water temperature control.
Error codes when the
111
121
510
701
valves fails
1. Visual inspection: connection / breakage of wires.
2. Listen for "clunk" sounds from the gas valves opening right after fan motor
Diagnostic
initiates.
3. Check voltages and resistance of coils; proper range of values shown
below.
Color / Number of wires
Blue -Light blue
78 to 100 VDC (during operation) / 0.9 to 1.3 kΩ
Blue -Green
78 to 100 VDC (during operation) / 1.3 to 1.9 kΩ
Blue -Orange
78 to 100 VDC (during operation) / 1.3 to 1.9 kΩ
Blue -Red
78 to 100 VDC (during operation) / 0.9 to 1.7 kΩ
White –Red
1.0 to 15 VDC (during operation) / 20 to 40 Ω
(Proportional valve)
EM440 (for LP model) and EM441 (for NA model) is an
assembly of the gas manifold with gas valve assembly.
For safety reasons, these assemblies should be installed
in the unit as a whole set. The diagram below shows the
gas valve assembly.
4 - 1 / 2 "( 1 1 4 m m )
18
4-1/2(119mm)
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-5. Flame rod
Unit Part #
#106
AOS Part #
EKK0E
Checkpoint
I
To detect flames while the water heater is in operation.
Function
1. Unable to detect flames when flames actually do occur
2. Detecting a false flame when no flames actually occur
1. The water heater stops operating. The "111" and/or "121" error code(s)
Effects on the water will display.
heater if flame rod fails
2. The water heater will not initiate the ignition process. The "721" error
code will display.
Error codes when the
111
121
721
flame rod fails
1. Visual inspection: connection / breakage of wires or soot buildup on rod.
Diagnostic
2. Check amperes: proper range of values shown below.
Failure event
Orange(17) - Flame rod
Color / Number of wires
(Between the flame rod and
the computer board)
(During operation)
More than DC 1 μA
The flame rod is assembled with the AFR rod.
1 - 1 / 8 " ( 2 9 .3 m m )
1-3/4" (44mm)
Detecting elements of the flame rod
Leads to computer board
3 / 4 " ( 1 7 .5 m m )
AFR
Rod
19
1 / 4 " ( 7 .5 m m )
rod
1/2" (12mm)
Flame
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-6. AFR rod
Unit Part #
#106
AOS Part #
EKK0E
Checkpoint
I
-Checks flame conditions during combustion.
-When AFR rod detects unexpected flame conditions, the the computer of
the water heater makes adjustments in the fan motor speed to compensate.
1. Unable to detect flames when flames actually do occur
Failure event
2. Detecting a false flame when no flames actually occur
1. The water heater will not initiate the ignition process. The "721" error
Effects on the water code will display.
heater if AFR rod fails
2. The fan motor speed cannot be modulated properly under abnormal flame
conditions, which can result in excessive CO emission.
Error codes when the
101
391
991
AFR rod fails
1. Visual inspection: connection / braking of wires, soot on it.
Diagnostic
2. Check voltages: proper range of values are shown below.
Function
Yellow(8) - AFR rod
Color / Number of wires
(During operation)
(Between the flame rod and
More than DC 0.5 μA
the computer board)
The AFR rod is assembled with the flame rod.
Leads to computer board
AF R
Ro d
20
1 / 4 " ( 7 .5 m m )
3 / 4 " ( 1 7 .5 m m )
rod
1/2" (12mm)
F lame
1 - 1 / 8 " ( 2 9 .3 m m )
1-3/4" (44mm)
Detecting elements (AFR and flame rods)
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-7. Heat exchanger
EM415
Check
(Regular model)
Unit Part #
AOS Part #
N/A
EM45C
#211 (ASME model)
point
(ASME model)
Absorbs heat from combustion and transfer it to water through the heat
Function
exchanger pipes.
1. Clogged heat exchanger fins and/or cracks on the heat exchanger walls.
Failure event
2. Leaking exhaust gas.
3. Improper heat transfer can cause the water in heat exchanger to boil.
1. Water leakage from the heat exchanger
Effects on the water
2. Exhaust gas leakage (if this occurs, an overheat cutoff fuse is in place to
heater if the heat
detect this event and immediately stop the water heater from operating)
exchanger fails
3. Abnormal sounds during combustion
Error codes when the
N/A
heat exchanger fails
1. Visual inspection: soot deposits, cracks on the heat exchanger walls,
and/or water leakage from the heat exchanger.
2. In the event of abnormal sounds during combustion:
Diagnostic
A. Inspect for soot buildup inside the heat exchanger.
B. Inspect for scale buildup inside the heat exchanger pipes. Scale
buildup obstructs proper heat transfer to the water, thereby overheating
the heat exchanger and causing damage.
#210 (Regular model)
Color / Number of wires
N/A
Only the ASME model has a plate as shown in the
drawings below. The configuration and material of
the ASME model heat exchanger are different from
the regular model, as well.
Regular model
1 4 - 1 / 1 6 "( 3 5 7 .1 m m )
ASME Model
21
1 7 - 1 / 2 "( 4 4 5 .7 m m )
9 - 1 / 4 "( 2 3 5 .6 m m )
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-8. Flow sensor
Unit Part #
#429
AOS Part #
EKH33
Checkpoint
H2
Detects and measures water flow rate using a spinning impeller and magnetic
pick-up.
Unable to detect or measure any water flow rate.
Function
Failure event
Effects on the water
heater if flow sensor Ignition sequence does not start (water heater will not initiate any operation)
fails
Error codes when the
441 (only within Easy-link and Multi-unit systems)
flow sensor fails
1. Visual inspection: connection /breakage of wires and/or debris on impeller.
Diagnostic
2. Check voltages: proper range of values shown below.
Red - Black
Color / Number of wires
4.0 to 5.5 VDC (Input)
1 to 4 VDC (pulse)
White(+)-Black(GND)
1,200 pulse / min (more than 20 Hz)
Water OUT
2” (50mm)
Water IN
7-7/7” (200mm)
7-1/8” (30mm)
Water IN
Red
White
Black
22
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-9. Water control valve (flow adjustment valve and bypass valve)
Unit Part #
#423
AOS Part #
EKH32
Checkpoint
J
The water control valve in the water heater has three functions of water
control: flow adjustment, bypass, and two-way) This valve is exactly the
same as the water valve in the T-M50. Its functions are as follows:
1. Controls water flow to properly control the output hot water
temperature.
(The function of the flow adjustment valve)
2. Mixes the hot water from the heat exchanger and the cold water from
the water inlet to properly adjust the water heater’s outlet water
Function
temperature.
(The function of the bypass valve)
3. Stabilizes the water temperature in the heat exchanger, preventing
low-temperature corrosion caused by heat exchanger condensation.
(The function of the bypass valve)
4. Prevents water from flowing through the heat exchanger when water
heater is not in operation to protect the heat exchanger.
(The function of the two-way valve)
1. Water leakage from valve.
Failure event
2. The valve cannot modulate or make open / close positions.
1. Water leakage from failed valve can damage other water heater
components.
Effects on the water 2. Temperature fluctuations may occur in the hot water output of the water
heater if water control heater, due to inability to modulate water flow.
valve fails
3. Can cause water to still flow through the heat exchanger when the water
heater is not operating, possibly damaging the heat exchanger and causing
water leaks.
Error codes when Water
651
control valve fails
1. Visual inspection: connection / breakage of wires, motor drive locked due
Diagnostic
to scale buildup, and /or water leakage.
2. Check voltages and resistance; proper range of values shown below.
NOTE: Color/Number of wires and pictures are on the following page.
23
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-9. Water control valve (flow adjustment valve and bypass valve)
Color / Number of
wires
Blue-Brown
13.0 to 16.0 VDC
Orange-Brown
ON: 12.5 to 16.0 VDC
Red-Brown
(0° position) 1 VDC less
OFF: 0 to 1 VDC
3-3/ 8" (8 7mm)
3 - 3 / 4 " ( 9 5 .6 m m )
The water control valve contains the flow adjustment valve and the
bypass valve.
5-3/8" ( 137mm)
Water adjustment valve
24
Bypass valve
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-10. Thermistors
#422 (Inlet)
Unit Part #
EKK38 (Inlet)
#433 (Output)
AOS Part #
E1 (Mixing)
EKK2T (Output)
#418 (Mixing)
Checkpoint
EX00H (Mixing)
E2 (Output)
E3 (Inlet)
Function
Measure cold / hot water temperatures in the water heater.
Failure event
Unable to properly measure water temperatures within the water heater.
Effects on the water If the thermistors fail open or short, error code appears before starting operation.
heater if thermistor If resistance values are just off, water heater will have temperature fluctuations in
fails
hot water.
Error codes when
311 (Output)
321 (Inlet)
331 (Mixing)
thermistors fails
1. Visual inspection: connection / breakage of wires and/or debris on thermistor.
Diagnostic
2. Check voltages and resistance; proper range of values shown below.
Inlet
Black (42)-Black
68˚F (20°C) 9.0 to 13 kΩ
Color / Number of Output Black (12)-Black
122˚F (50°C) 3.3 to 4.4 kΩ
wires
176˚F (50°C) 1.4 to 1.8 kΩ
Mixing
Black (113)-Black
(see table below for more resistance values)
Black
(Inlet thermistor) 42
Blue
Black
Insulating
(Mixing thermistor) 113
(Output thermistor) 12
Resistance values of thermistors as a function of temperature
25.00
Resisitance / kΩ
20.00
15.00
10.00
5.00
0.00
20
40
60
80
100
120
140
Temperature / ºF
25
160
180
200
220
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-11. Hi-limit switch
Unit Part #
#432
AOS Part #
EKN34
Checkpoint
C1
-Based on bi-metal thermal expansion.
-Detects excessively high water temperature (more than 194˚F or 90˚C) in pipes
of the heat exchanger.
Function
-After detection, communication between the computer board and gas valves are
severed, shutting down the water heater instantly. The "111" or "121" error
codes will display.
1. Unable to detect excessively high water temperatures if switch fails "closed".
Failure event
2. Continuous detection of excessively high water temperatures (regardless of
what the actual water temperature is) if switch fails "open".
1. Unable to shut down the water heater if the water temperature from the heat
exchanger exceeds 194˚F (90˚C).
Effects on the water
Note: The mixing and output thermistors always act as backup hi-limit
heater if hi-limit switch
detectors to detect excessively high water temperatures in the heat exchanger.
fails
2. The water heater is always shut down immediately after the ignition process,
and either the "111" or "121" error code will display.
111
112
Error codes when hi-limit The T-M32 doesn't have the "141" error code that was used in our previous
switch fails
models. This error code is now replaced by the "111" and the "121" error
codes.
Diagnostic
1. Visual inspection: connection / breakage of wires. Possibility also includes
scale deposits inside the heat exchanger.
2. Check voltages and resistance: proper range of values shown below.
Color / Number of wires
Blue-Blue
Less than 1.0 Ω
When temperatures exceed 194˚F (90˚C), the reset button trips and switch goes to OFF mode.
OFF mode: to reset switch back to ON mode, press the reset button
Reset Button
"9 0" m a r k
9 0
1-3/8" (35mm)
ON mode:<194˚F (90˚C)
3 / 4 " ( 1 8 .4 m m )
26
5/8" (15mm)
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-12. Overheat cutoff fuse
Unit Part #
#403
AOS Part #
EM387
Checkpoint
C2
The overheat cutoff fuse contains solder with a melting point of 430˚F
(221˚C).
Detects excessive temperatures within the water heater, especially around
Function
the heat exchanger and combustion chamber. Upon detection,
communication between the computer board and gas valves will sever,
shutting down the water heater instantly. The "111" or "121" error code
will display.
1. Unable to detect the excessively high temperatures within the water
Failure event
heater.
Effects on the water 1. Flames from burner may penetrate a ruptured/damaged heat exchanger.
heater if the overheat 2. Gas valves will not operate.
cutoff fuse fails
Error
codes
when
111
121
overheat cutoff fuse
fails
1. Visual inspection: connection / breakage of wires.
Diagnostic
2. Check voltages and resistance: proper range of values shown below.
Color / Number of wires
Blue-Blue
Less than 1.0 Ω
Solder will melt at temperature exceeding 430˚F (±9˚F) / 221˚C (±5˚C)
3 1- 1 /2 "( 80 0 mm )
27
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-13. Freeze protection heaters
#404
Unit Part #
#410
#415
EKN86
AOS Part #
#426
EX002
EKK2P
Checkpoint
L
EM45V
Prevents the heat exchanger, water valves, and water pipes within the water
heater from freezing. The heaters are but one of the freeze protection
devices in the water heater.
Open circuit failure: ceramic heaters do not receive the voltage needed to
Failure event
heat up.
Effects on the water Ceramic heaters do not activate, allowing water contained in the heat
heater if heater fails
exchanger to freeze up, possibly causing the heat exchanger to burst.
Error codes when hears
N/A
fails
1. Visual inspection: connection / breakage of wires and the condition of the
heaters.
Diagnostic
2. Check: whether those are in the normal range as shown in the following
table.
Function
Color / Number of wires
Black - Black
90 to 110 VAC (during freeze protection operation)
The water heater has four types of the heaters in it. All of them for protecting of the heat
exchanger, the water pipes, the water inlet and the water outlet.
Pipe heater with Block heater (#426 / EM45V)
Heater (#410 / EX002)
Inlet heater (#415 / EKK2P)
Pipe heater (#404 / EKN86)
)
28
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-14. Computer board
Unit Part #
#701
AOS Part #
EM376
Checkpoint
Function
Controls the functions of the most parts in the water heater.
Failure event
Malfunctioning computer
N/A
When the computer board failed, the control from the computer and/or
the multi-system control will be abnormal.
The following are the typical examples of when the computers fail:
1. Unable to control proper combustion during operation.
2. Unable to detect correct signals from any/all water heater sensors.
Effects on the water 3. Unable to control water valves, which may cause output temperature
heater if the computer fluctuations.
board fails
4. Errors in its self-diagnostics. In order to self-diagnose properly, the
computer sends a low voltage signal into its circuit. When the computer
does not detect a return signal, from this circuit, the "701" error code will
appear.
5. Unable to communicate to other computers in the water heater models
and/or the multi-unit controller (TM-MC01) during the multi-unit system
operation.
Error codes when the
701
721
741
761
computer board fails
Visual inspection: connection / breakage of wires and or burn marks on the
Diagnostic
computer board.
Color / Number of wires
N/A
8- 1/ 8" (2 0 6m m)
1- 5/ 8" (4 0m m)
5 " ( 12 9m m)
29
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-15. Transformer
Unit Part #
#702
AOS Part #
EM454
Checkpoint
A1,A2
-To transform input voltage from 120 to 100 VAC.
-Every electrical component of the water heater is designed to only work
Function
with a 100 VAC power supply, therefore, the T-M32 comes equipped with
this transformer.
1. There is no power coming from the transformer.
Failure event
2. The voltage from the power supply cannot be converted to 100 VAC.
1. The water heater does not operate due to lack of power from
Effects on the water transformer.
heater if transformer fails 2. A failed transformer can cause electrical damage to other electrical
components within the water heater.
Error
codes
when
N/A
transformer
1. V isual inspection: connection / breakage of wires and/or signs of
Diagnostic
electrical damage.
2. Check voltages of the transformer: Proper range of values shown below.
Color / Number of wires
White – Black
120 VAC / less than 1.0 Ω
Brown - Brown
100 VAC ±5 / less than 1.0 Ω
Brown-Brown
To power the computer board
(100 VAC)
4- 1/ 8" ( 10 6m m)
White-Black
From the 120 VAC power supply
3 - 1 / 4 "( 8 3 m m )
1 - 1 / 2 "( 3 7 .5 m m )
3 -1 /4 "( 79 mm )
TD1 -236
1 20 V 10 0V
5- 7/ 8" ( 15 0m m)
5 -7 /8 " ( 15 0 mm )
30
2 -5 /8 "( 68 mm )
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-16. GFI
Unit Part #
#712
AOS Part #
EM207
Checkpoint
A,A1
-Detects electrical leakage in the water heater.
-Stops providing power to the water heater in the case of electrical leakage.
1. ON-failure: Always in the ON mode (never trips).
Failure event
2. OFF-failure: Always in the OFF mode (always stays tripped).
1. ON-failure: GFI cannot detect electrical leakage within the water heater.
Effects on the water
2. OFF-failure: the water heater does not receive any power from the GFI, which
heater if the GFI fails
means the water heater cannot operate.
Error codes when the GFI
N/A
fails
1. V isual inspection: connection / breakage of wires and/or some signs of
electrical damage on the GFI.
Diagnostic
2. Check the power supply to the GFI. If the red LED on the GFI lights up after
pressing the “test“ button, the GFI is receiving power. After verifying the power
supply, verify that 100 VAC is entering and leaving the GFI.
Function
Color / Number of wires
N/A
2-3/4" (70mm)
To the computer board
3/4" (20mm)
From transformer
1-7/8" (50mm)
1-7/8" (50mm)
31
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-17. Igniter
Unit Part #
#125
AOS Part #
EKN74
Checkpoint
B
-To ignite the gas / air mixtures when the water heater is ready to burn gas
on its burner surface.
-The output voltage of the igniter is more than 14 kVDC.
1. Unable to ignite during the ignition process.
Failure event
2. Makes attempts to ignite at all times.
1. The water heater cannot ignite during the ignition process and the "111"
Effects on the water or "121" error codes will display.
heater if the igniter fails
2. No effects on the water heater, however, the durability of the igniter
wears down.
Error codes when Igniter
111
121
fails
1. Visual inspection: connection / breakage of wires and /or an observed
Diagnostic
weak spark.
2. Check voltages: proper range of values shown below.
Function
Color / Number of wires
Purple(7)-Purple(7)
90 to 110 VAC
Igniter
The
high-voltage
igniter cable and
the purple wires
do not come with
Purple wire
14 kVDC
EKN74.
3 /4 " (2 0 mm)
High-voltage igniter cable
90 to 110VAC
1- 3/ 4" ( 4 4m m)
1-1/2" (38mm)
To High valtage
ignite cable
Power supply
AC 90 to 110V
32
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-18. Freeze protection thermostat
Unit Part #
#117
AOS Part #
EKJ59
Checkpoint
L
Temperature detecting device which prevents the pipes within the water
heater from freezing. When this device detects temperatures below
Function
36.5˚F (2.5˚C) inside the water heater, power is supplied to the electric
heaters to prevent the water heater from freezing.
1. ON-failure (Always senses freezing temperatures, regardless of actual
Failure event
temperature).
2. OFF-failure (Never senses freezing temperatures).
Effects on the water 1. The freeze protection heaters will always be ON, causing heat damage to
heater if the freeze components inside the water heater.
protection
thermostat 2. The freeze protection heaters will never be able to turn on, even under
fails
freezing temperatures, causing freeze damage to the water heater.
Error codes when the
freeze
protection
N/A
thermostat fails
1. Visual inspection: connection / breakage of wires and/or the body has
Diagnostic
been broken.
2. Check resistance and voltage: proper range of values shown below.
Color / Number of wires
Black - Black
ON mode: 90 to 110 VAC and less than 1 Ω
(itself)
OFF mode: less than 1 VAC and more than 1 MΩ
Activation and deactivation temperature of the T-M32’s freeze protection system
ON mode: 36.5˚F (+6.3˚F -2.7˚F)
2.5˚C (+3.5˚C -1.0˚C)
OFF mode: above 46.4˚F
above 8 ˚C
7 / 8 " ( 2 2 .2 m m )
1 - 3 / 8 " ( 3 3 .5 m m )
1 / 4 " ( 5 .7 m m )
33
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
10-19. Surge box
Unit Part #
#715
AOS Part #
EM385
Checkpoint
A2,A3
Protects the unit from high voltage and/or high electric current caused by
lightning.
Function
There are 2 types of surge absorbers in the water heater Surge absorber A is
activated by voltage higher than 220 V, the other one is activated by voltage
higher than 680 V.
1. Open-failure of the absorber and/or fuse.
Failure event
2. Short-failure of the absorber.
1. Unable to protect the computer board if high voltage gets applied to the
Effects on the water
unit. The computer board can short out, stopping all operations.
heater if the Surge box
2. The unit cannot operate because the absorber shorted out, causing the
fails
fuse to break open.
Error codes when the
N/A
Surge box fails
1. V isual inspection: burn marks on components and/or connection /
Diagnostic
breakage of wires.
2. Check resistance and voltage: proper range of values shown below.
Color / Number of wires
White-Black
108 to 132 VAC
Surge absorber A: 220 V
Fuse: 10 A
3 1/ 3 2 "( 2 5 m m )
1 - 3 /4 "( 4 3 .2 m m )
1 / 2 "( 1 3 .6 mm )
2 - 7 / 8 "( 7 3 m m )
Surge absorber B: 680 V
34
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
11. Fault Analysis & Specifications
Remarks:
1. Proper range of values of voltage & resistance shown below.
2. Please refer to the wiring diagram for checkpoint positions.
3. Remove power to water heater when checking for continuity, disconnections, resistance values, etc.
Natural of Fault
Diagnosis
on 1 Check the power supply
[1] Check the power supply from GFI to the PCB
temperature remote
(Refer to section12-2)
controller, even when [2] Check the power supply line to the water heater
remote is turned on.
2 Fault of GFI
Normal: 100 VAC between (white-black)
Normal: 100 VAC between (brown-brown)
3 Fault of transformer
[1] Disconnection / breakage of wires
Normal: 120 VAC between (white-black)
Normal: 100 VAC between (brown-brown)
4 Blown fuse at surge box (10 A)
5 Fault of PCB
[1] No voltage at remote control terminal
Normal: 11 to 25 VDC between (white-black)
6 Disconnection / short-circuit / grounding of remote wires
Normal: 11 to 25 VDC between (white-black)
7 Fault of PCB of remote control
[1] Check for normal voltage at terminal
・ No
Check
point
display
・It takes long time to get
hot water at the fixtures
1 The time it takes to deliver hot water from the water heater to fixtures
depends on the length of piping between them. The longer the distance
and/or the bigger the pipes, the longer it will take to get hot water.
2 If you need to receive hot water to fixtures quicker, you may want to consider
a hot water recirculation system.
・The water is not hot 1 Check cross pluming between cold water lines and hot water lines.
2 Check whether the gas supply pressure is enough.
enough
3 Check whether the temperature setting is too low.
・The water is too hot 1 Check whether the temperature setting is too high.
・The hot water is not 1 Make sure the unit has a 120 VAC / 60 Hz power supply.
available when a 2 If the remote controller is used, check whether the power button is
turned on.
fixture is opened
3 Check that the filter on the cold water inlet is clean.
4 Check whether the hot water fixture is sufficiently open to draw at
least 0.5 GM through the water heater.
35
A
A1
A2,A3
A1
F
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Natural of Fault
Diagnosis
Checkpoint
・The hot water is not 5 Check that the filter on the cold water inlet is clean.
available when a fixture 6 Check whether or not the unit is frozen.
7 Check if there is enough gas in the tank. (for propane units)
is opened
・The hot water turns cold 1 Check whether the flow rate is high enough to keep the water
heater running.
and stays cold
2 Check if there is a recirculation system installed and check also if
the recirculation line has enough check valves.
3 Check that the filter on the cold water inlet is clean.
4 Check that the fixtures are free from debris and obstructions.
・The fan motor is still 1 This is normal operation. After operation has stopped, the fan
motor keeps its running for 35 seconds in order to re-ignite
spinning after operation
quickly, as well as purge all the exhaust gas out of the flue.
has stopped
・Abnormal sound
water heater
Natural
of
Fault
from 1 Check the gas type of the water heater.
2 Check how long the water heater has been installed and in use.
3 Check the installation place.
4 Check the altitude / elevation of area of where the water heater
installed.
5 Check the vent length, when the water heater has been installed
indoors.
6 Check the type of vent cap, when the water heater has been
installed outdoors.
7 Check if there is any blockage in the intake air and/or exhaust.
8 Check if there is dust and lint in burner and heat exchanger, when
the water heater has been installed in laundry room.
9 Check if there is grease and dirt in burner and fan motor, when
the water heater has been installed in restaurant.
10 Check the manifold pressure in the water heater.
Malfunction description
Cancellation method
・ Fluctuation -Fault of gas solenoid valves (SV1 & SV3) during
of hot water change of the combustion stage
temperature
-Fault of flow adjustment valve
Diagnosis
1 Check whether the filter in cold water inlet is cleaned.
2 Check whether the gas supply pressure is adequate.
3 Check for cross connections between cold water lines and hot water lines.
36
Checkpoint
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Natural
Fault
of
Diagnosis
Checkpoint
・ Fluctuation 4 Fault of PCB in the water heater
of hot water [1] No voltage to gas solenoid valve (SV1).
Normal: 78 to 100 VDC between COM (blue) & #9 (green)
temperature
(during operation)
[2] No voltage to gas solenoid valve (SV3).
Normal: 78 to 100 VDC between COM (blue) & #73 (red)
(during operation)
5 Gas solenoid valve (SV 1) fault
[1] Disconnected wiring to gas solenoid valve (SV1)
Normal: 1.3 to 1.9 kΩ between COM (blue) & #9 (green)
[2] Disconnected wiring to gas solenoid valve (SV3)
Normal: 0.9 to 1.7 kΩ between COM (blue) & #73 (red)
6 Fault of PCB in the water heater
No voltage to water control valve
Normal: 13.0 to 16.0 VDC between (blue-brown)
Normal: ON 12.5 to 16.0 V / OFF 0 to 1 V between (orange-brown)
Normal: DC 1 V less (0˚ position) between (red-brown)
7 Fault of Water control valve
Normal: 0.09 to 0.2 kΩ between (red-black)
Error Code
031
Malfunction description
Incorrect dipswitch setting fault
C
C
J
J
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
Check the dipswitch settings on all PCBs
Error Code
Malfunction description
Cancellation method
On the PCB, press the INC and DEC
buttons simultaneously for 3 sec. Then
turn the power off.
Warning for the “991” error code
(Refer to section 12-3)
Diagnosis
101
1 Check the gas type of the water heater.
2 Check how long the water heater has been installed and in use.
3 Check the installation location.
4 Check the altitude / elevation of area of where the water heater installed.
5 Check the vent length, when the water heater has been installed indoors.
6 Check the type of vent cap, when the water heater has been installed
outdoors.
7 Check if there is any blockage in the intake air and/or exhaust.
37
Checkpoint
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
101
Error Code
Diagnosis
8 Check if there is dust and lint in burner and heat exchanger, when the water
heater has been installed in laundry room.
9 Check if there is grease and dirt in burner and fan motor, when the water
heater has been installed in restaurant.
10 Check the manifold pressure in the water heater.
Malfunction description
Ignition failure
111
Error code is
shown after
three failed
attempts at
iginition
Checkpoint
Cancellation method
Turn off the power or water supply
Diagnosis
1 Check gas supply and inlet gas pressure (Refer to section 1)
2 Check the igniter (Refer to section 10-17)
V isual inspection: connection / breakage of wires and/or observed weak
spark.
[1] Cracks / soot on igniter rod
[2] Improper gap between burner & igniter rod
Normal gap: 0.16" (4mm)
[3] PCB fault
Normal: 90 to 110 VAC at #7 (purple-purple) (during ignition)
3 PCB fault
[1] No voltage to main gas solenoid valve (MV)
Normal: 78 to 100 VDC between COM (blue) & #3 (light blue)
(during operation)
[2] No voltage to gas solenoid valve (SV2)
Normal: 78~100 VDC between COM (blue) & #53 (orange)
(during operation)
[3] No voltage to gas proportional valve (VG0)
Normal: 1~15 VDC between white & red (during operation)
4 Gas solenoid valve fault
[1] Main gas solenoid valve (MV) fault
Normal: 0.9 to 1.3 kΩ between COM (blue) & #3 (light blue)
[2] Gas solenoid valve (SV2) fault
Normal: 1.3 to 1.9 kΩ between COM (blue) & #53 (orange)
[3] Gas proportional valve (VG0) fault
Normal: 1 to 15 VDC between white & red (during operation)
5 Disconnected / damaged O.H.C.F. (Refer to section 10-12)
V isual inspection: connection / breakage of wires.
Normal: 1 Ω or less between blue & blue
38
Checkpoint
B
C
H1
C
H1
C2
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
111
Error code is
shown after
three failed
attempts at
ignition
Diagnosis
Checkpoint
6 Disconnected / damaged hi-limit switch. (Refer to section 10-11)
V isual inspection: connection / breakage of wires.
Normal: 1 Ω or less between blue & blue
7 Inspect flame rod
[1] Check for any soot on the rod.
[2] Check the connection of ground wire; make sure there is firm contact to
the ground of the water heater.
(in this case, the wire is contacted to the manifold surface.)
[3] PCB fault
During operation: more than 1 μA through the flame rod wire (orange)
[4] Flame rod fault
During operation: more than 1 μA through the flame rod wire (orange)
C1
I
8 Check if hi-limit switch is properly functioning.
Error Code
Malfunction description
Loss of flame
121
Error code is
shown after
three failed
attempts at
ignition
Cancellation method
Turn off the power or water supply
Diagnosis
1 Check gas supply and pressure
(Refer to section 1)
2 PCB fault
[1] No voltage to gas main solenoid valve (MV)
Normal: 78 to 100 VDC between COM (blue) & #3 (light blue)
(during operation)
[2] No voltage to gas solenoid valve (SV2)
Normal: 78 to 100 VDC between COM (blue) & #53 (orange)
(during operation)
[3] No voltage to gas proportional valve (VG0)
Normal: 1 to 15 VDC between white & red (during operation)
3 Gas solenoid fault
[1] Main gas solenoid valve (MV) fault
Normal: 0.9 to 1.3 kΩ between COM (blue) & #3 (light blue)
[2] Gas solenoid valve (SV2) fault
Normal: 1.3 to 1.9 kΩ between COM (blue) & #53 (orange)
[3] Gas proportional valve (VG0) fault
Normal: 1 to 15 VDC between white & red (during operation)
4 Check for soot on the flame rod
[1] Clean the flame rod
[2] PCB fault
During operation: more than 1 μA through the flame rod wire (orange)
39
Checkpoint
C
H1
C
H1
I
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
121
Error code is
shown after
three failed
attempts at
ignition
Error Code
Diagnosis
5 Disconnected / damaged O.H.C.F.
(Refer to section 10-12)
V isual inspection: connection / breakage of wires.
Normal: 1 Ω or less between blue & blue
6 Check if hi-limit switch is properly functioning.
7 Disconnected / damaged hi-limit switch. (Refer to section 10-11)
V isual inspection: connection / breakage of wires.
Normal: 1 Ω or less between blue & blue
Malfunction description
Disconnected / short-circuited output thermistor
311
Error Code
Error Code
C1
Turn off the power or water supply
Checkpoint
1 Output thermistor fault
(Refer to section 10-10)
V isual inspection: connection / breakage of wires and/or debris on
thermistor.
Check voltage / resistance between black & black (#12).
Refer to Section 8 for proper range of values.
Malfunction description
E2
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 Inlet thermistor fault
(Refer to section 10-10)
V isual inspection: connection / breakage of wires and/or debris on
thermistor.
Check voltage / resistance between black & black (#42).
Refer to Section 8 for proper range of values.
Malfunction description
Disconnected / short-circuited mixing thermistor
331
C2
Cancellation method
Diagnosis
Disconnected / short-circuited inlet thermistor
321
Checkpoint
Cancellation method
Turn off the power or water supply
Diagnosis
1 Mixing thermistor fault
(Refer to section 10-10)
V isual inspection: connection / breakage of wires and/or debris on
thermistor.
Check voltage / resistance between black & black (#113).
Refer to Section 8 for proper range of values.
40
E3
Checkpoint
E1
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
Malfunction description
Disconnected AFR rod
391
Error Code
441
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 AFR rod fault
(Refer to section 10-6)
V isual inspection: connection / breakage of wires, soot on it.
Malfunction description
Flow sensor failure
(Only Easy-link and Multi-unit system)
I
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 Flow sensor failure
(Refer to section 10-8)
V isual inspection: connection/ breakage of wires andor debris on impeller.
Check voltage / resistance between (red & black) or (white & black)
Error Code
510
Malfunction description
H2
Cancellation method
Fault of driving circuit for main gas solenoid
valve (MV)
Turn off the power supply
(The computer checks the condition of the main
gas valve immediately after every operation)
Diagnosis
1 PCB and /or main gas valve fault
(Refer to section 10-4 & 10-14)
V isual inspection of gas valves: connection / breakage of wires.
Normal: 78 to 100 VDC between COM (blue) & #3 (light blue)
(during operation)
V isual inspection of PCB: connection / breakage of wires and/or burn marks
on the computer board.
2 Main gas valve fault
41
Checkpoint
C
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
551
Malfunction description
Cancellation method
Fault of driving circuit for any of the gas
solenoid valves (SV1, SV2, and/or SV3)
Turn off the power supply
(The computer checks the condition of the
solenoid valves 6 hours after every operation)
Diagnosis
Checkpoint
1 PCB and /or gas valve fault
(Refer to section 10-4 & 10-14)
V isual inspection of gas valves: connection / breakage of wires.
Normal: DC78 to 100 VDC between COM (blue) & #9 (green)
(during operation)
Normal: DC78 to 100 VDC between COM (blue) & #53 (orange)
(during operation)
Normal: DC78 to 100 VDC between COM (blue) & #73 (red)
(during operation)
V isual inspection of PCB: connection/breakage of wires and/or burn marks
on the computer board.
2 Gas solenoid valve fault (SV1, SV2, and/or SV3)
Error Code
Malfunction description
Fan motor fault
611
C
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 PCB and fan motor fault
(Refer to section 10-3 & 10-14)
V isual inspection of fan motor: connection / breakage of wires or dust
buildup (causing electrical shortage)
Normal: 110 to 160 VDC between red & blue (during operation)
Normal: 13 to 17 VDC between yellow & blue (during operation)
Normal: 2.0 to 6.5 VDC between orange & blue (during operation)
G
Verify fan motor speed of the water heater using the "diagnostics mode" of
the temperature remote controller. See the "12-1. How to diagnose the
water heater using the temperature remote controller.”
V isual inspection of PCB: connection / breakage of wires and /or burn marks
on the computer board.
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
Malfunction description
Pump failure
631
Cancellation method
Turn off the power
Diagnosis
Checkpoint
1 Check whether the pump connected to PCB works properly.
Error Code
651
Error Code
661
Malfunction description
Water control valve fault
(Flow adjustment function)
(Only Easy-link and Multi-unit system)
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 PCB and flow adjustment valve fault
(Refer to section 10-9 & 10-14)
V isual inspection of Water control valve: connection / breakage of wires,
motor drive locked due to scale buildup, and/or water leakage.
Normal: 13.0 to 16 VDC between (blue-brown)
Normal: ON:12.5 to 16.0 VDC / OFF: 0 to 1 V
Normal: 1 V Less than (0˚ position)
V isual inspection PCB: connection / breakage of wires and/or burn marks on
the computer board.
J
Malfunction description
Water control valve fault
(Bypass valve function)
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 PCB and bypass valve fault
(Refer to section 10-9 & 10-14)
V isual inspection of Water control valve: connection / breakage of wires,
motor drive locked due to scale buildup, and/or water leakage.
Normal: 13.0 to 16 VDC between (blue-brown)
Normal: ON:12.5 to 16.0 VDC / OFF: 0 to 1 V
Normal: 1 V Less than (0˚ position)
V isual inspection PCB: connection/ breakage of wires and/or burn marks on
the computer board.
J
43
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
701
Error Code
Malfunction description
1 PCB fault
[1] Fault of preparation for the mixing thermistor
operation.
Turn off the power or water supply
[2] Fault of driving circuit for Gas Proportional
Valve(VG0)
Diagnosis
Checkpoint
1 Check the PCB and /or gas proportional valve
(Refer to section 10-4 &10-14)
V isual inspection PCB: connection / breakage of wires andor burn marks on
the computer board.
V isual inspection gas proportional valve: connection / breakage of wires of
the gas proportional valve.
Normal: 20 to 40 Ω between (white) & (red)
H1
Malfunction description
False flame detection
721
Error Code
741
Cancellation method
Cancellation method
Turn off the power or water supply
Diagnosis
Checkpoint
1 False flame detection (5 sec.)
Flame rod (Insulated resistance) fault
Malfunction description
I
Cancellation method
Restoring proper cable connections
between the water heater and the
Miscommunication between water heater and Remote controller. When the computer
remote controller
detects proper connections between the
water heater and the remote controller,
"741" error code will cease to display.
Diagnosis
1 Temperature remote controller or PCB fault
2 Check for signs of power surges.
44
Checkpoint
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Error Code
761
Malfunction description
Cancellation method
Restoring proper cable connections
between all the T-M32’s and the
multi-unit controller (TM-MC01). When
Miscommunication between Parent and Child
the computer detects proper connections
units for Easy-Link systems or Multi-Unit system.
between the multi-unit controller and the
units (water heater), "761" error code will
cease to display.
Diagnosis
Checkpoint
1 Inspect cable connections between Parent and Child units.
2 Inspect cable connections between Multi-unit controller and water heaters.
3 Check for signs of power surges.
Error Code
991
Malfunction description
Cancellation method
Turn off the power or water supply
If not possible, press and hold the INC
and DEC buttons on the computer board
simultaneously for more than 3 sec.
Abnormal burning
(Refer to section 12-3)
Diagnosis
1 Check the gas type of the water heater.
2 Check how long the water heater has been installed and in use.
3 Check the installation place.
4 Check the altitude / elevation of area of where the water heater installed.
5 Check the vent length, when the water heater has been installed indoors.
6 Check the type of vent cap, when the water heater has been installed
outdoors.
7 Check if there is any blockage in the intake air and/or exhaust.
8 Check if there is dust and lint in burner and heat exchanger, when the water
heater has been installed in laundry room.
9 Check if there is grease and dirt in burner and fan motor, when the water
heater has been installed in restaurant.
10 Check the manifold pressure in the water heater.
45
Checkpoint
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12. Controls and settings
12-1. Diagnosis using the remote controller………………....………….….…………….….……...…..……….….……… 47
12-2. The error-call button: Verifying functionality of computer board, Displaying error code
history, and Clearing error code history memory…………….………………………….………………………….
50
12-3. Clearing the “101” and “991”error code…………………………………………………………………………………. 51
12-4. AFR rod function…………………………………………………………………………………………………………………….
52
12-5. Dipswitch settings…………………..………………..…………………….……….……….......................................
53
12-6. Assigning unit numbers in the Easy-link system……………….……………………………………………………..
55
12-7. (A) ON / OFF conditions: Overview…….….……………………….………………………………………………………
56
12-7. (B) ON / OFF conditions: BTU requirements.….…………………….…………………................................
57
12-8. (A) Pump control ON / OFF Condition (Only for single and Easy-link system)………………………….. 58
12-8. (B) Pump control ON / OFF Conditions: BTU requirements for Re-circulation mode……………….. 59
12-9. Multi-unit system ON / OFF conditions……………………………...…………….……………………………………. 60
12-10. Operation time for unit rotation………………………………………….………...………………………………………. 62
12-11. Individual unit operation in multiple-system while the multi-unit controller (TM-MC01) is
under abnormal conditions (Individual operation mode)……...……………………….
63
12-12. High Altitude Region Support Software (FM+ and INPUT-)……………………………………………………… 64
12-13. Checking the Flow Rate by Computer Board……………………………………………….………………………….
65
12-14. Relay selection for the pump control connection……………….……………………………………………….….
66
12-15. Adjusting manifold gas pressure………………...……….…………………………………………………………………. 67
12-16. Manually adjusting the fan motor speed………………………………………………………………………………… 69
12-17. Freeze protection system………………….……………………………………………………………………………………. 70
12-18. Freeze protection for recirculation systems………………………………………………...............................
72
12-19. Draining the unit and cleaning the inlet water filter…….…………………………………………………………. 74
46
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-1. Diagnosis using the remote controller
<Individual unit>
1. Press the "HOT" button and the "COLD" button simultaneously for
“TIME”
at least 5 seconds to enter “Diagnostic mode”.
2. Scroll up or down to the needed information (mode #) of the
Button
“HOT”
Button
“COLD”
Button
T-M32 by pressing the “HOT” or “COLD” buttons.
(Fig.1 shows mode #5 being selected.)
When selecting information, please refer to the table on p.49 for
the proper mode #.
3. Press the “INFO” button to fix the mode #, and the information to
which the mode # correlates to will display on the remote
controller. (Fig.3)
4. When the “ON / OFF” button is pressed or 5 minutes have elapsed
without pressing any buttons, the display will return to normal.
Mode #
Information
Fig.1
Fig.2
47
“INFO”
“BUZZER”
“ON/OFF”
Button
Button
Button
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
< For multiple units in the Multi-unit system and the Easy-Link system >
1. Press and hold the "HOT" and "COLD" buttons simultaneously for at least 5 seconds to enter
“Diagnostics Mode”.
2. "0" will be displayed on the remote controller. (See Fig. 1)
3. Scroll to the desired T-M32 unit # in the multi-unit system or the easy-link system by pressing the
"HOT" or the "COLD" buttons to scroll up or down.
NOTE: The definition of the unit #’s:
“0” will yield information about the Multi-unit system or the Easy-link system as a whole,
and numbers “1”, “2”, “3”… ”20” will yield information about each of the individual
T-M32’s installed in the Multi-unit system and Easy-link system.
In the Multi-unit system T-M32, a maximum of twenty units can be linked together. For
the Easy-link system, a maximum of four units can be linked as well.
4. Press the “INFO” button to fix the desired unit #.
5. When the desired unit # is fixed (Fig. 2 shows that unit #10 is being fixed), scroll up or down to the
needed information (mode #) of the unit by pressing the “HOT” or “COLD” buttons.
(Fig.3 shows mode #6 is being selected.) When selecting information, please refer to the table on
p.49 for the proper mode #.
6. Press the “INFO” button to select the mode #, and information to which the mode # correlates to will
display on the remote controller. (Fig4)
7. When the “ON/OFF” button is pressed or 5 minutes have elapsed without pressing any buttons, the
display will return to normal.
Whole
diagnostic mode
Fig.1
Unit #
Mode#
Fig.2
Fig.3
Information
Fig.4
For example, the figures above show how to arrive at the mixing temperature information for Unit
#10 in a Multi-Unit System.
48
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Description of mode numbers in “Diagnostics Mode”
Mode #
1
2
3
4
5
6
7
8
9
10**
Whole multi-unit system information (#0)
Total system rate
0 to 9,999 (×0.1 GPM) Total operation time
N/A
ON/OFF cycles
Quantity of connected
0 to 20 (units)
Fan motor speed
T-M32’s
Priority T-M32 number 0 to 20
Inlet temperature
Quantity of operational
0 to 20 (units)
Output temperature
T-M32’s
Set temperature
100 to 185 °F
Mixing temperature
Operation time during
Air-Fuel
ratio
rod
0 to 999 (minutes)
current rotation
current
ON/OFF cycles during
0 to 999 (times)
Flow rate
current rotation
Bypass valve position
Ratio of hot water and
N/A
cold water
11**
12**
13**
16**
26
27
28
29
30
31
32
0 to 9,999 (×10 hours)
0 to 9,999 (×100 times)
0 to 9,999 (rpm)
32 to 210 (°F)
Over 210°F =E5
Under 32°F =E0
0 to 999 (×0.1μA)
0 to 999 (×0.1 GPM)
0 to 9,999, closed position = 0
0 to 999 (%)
Error code history: displays most recent error code
Inlet temperature of
0 to 999 °F
the priority unit
Mixing temperature of
0 to 999 °F
the priority unit
14**
15**
Unit information (#1 to #20)
Error code history: displays 2 nd most recent error code
Error code history: displays 3 rd most recent error code
Clears memory in error code history*
N/A
N/A
Air-Fuel ratio stage
0 to 16, Normal condition = 6
Current value
of
0 to 9,999 (×0.1μA)
Proportional valve
st
“1” means 1 stage
The
number
of
“2” means 2 nd stage
Combustion stages
“3” means 3 rd stage
(T-M32 has 4 stages
th
“4” means 4 stage
for combustion.)
“0” means No burning
Energization time of
0 to 9,999 (×10 hour)
Unit
Estimated
output
0 to 9,999 (×100 BTU)
from Computer board
Actual output of Unit 0 to 9,999 (×100 BTU)
Integrating flow of
0 to 9,999 (×1000 gallon)
Unit
Integrating output of
0 to 9,999 MBTU/h
Unit
* Simultaneously press the “INFORMATION” button and the “BUZZER” buttons on the remote controller while in
mode# 14 for at least 5 seconds to completely clear the memory in the error code history.
** Mode #’s after #9 will be displayed as a number (e.g. “10”, “11”,……, “16”) on the remote controller. After #16, the
remote controller will cycle back to #1 again.
49
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-2. The error-code button: Verifying functionality of computer board,
Displaying error code history, and Clearing error code history memory
The T-M32 has the “Error-call button” on the computer
board that provides three main functions listed below.
The button is located next to the 7-seg LED (as shown in
the picture to the right).
7-seg LED
Error-call button
A.
Check if the computer board works properly
1. Turn on the ON/OFF button of remote controller.
2. If the computer board works properly, the 7-seg LED will light in a circular “0” pattern, one
segment at a time.
B.
Displaying error code history
1. Briefly press the “Error-call button” (do not hold down
the button).
2. If the T-M32 has had prior error codes, the 7-seg LED
will display the most recent error code first. Pressing
the button again will display the 2nd most recent error
code and so on (Computer saves a maximum of 12 error
codes). If the T-M32 has never had any error codes,
the 7-seg LED will display a bar “—“.
C.
Clearing error code history memory
1. Press and hold the “Error-call button” for at least
5 seconds.
2. The 7-seg LED will display “C”, “L” and “r” in succession
to signify that the computer board memory has been
erased of all error codes.
50
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-3. Clearing the “101” and “991” error code
The “101” and “991” error codes signify imperfect (abnormal) combustion, caused by insufficient intake
air and/or obstructions in the exhaust.
A.
If the “101” and “991” error code occurs, please check the following:
1. What is the water heater models gas-type: liquid propane or natural gas?
2. How long has the water heater been installed and been in use?
3. Where is the water heater installed: indoor, outdoor, attic, etc?
4. What is the altitude / elevation of the area of installation?
5. If installed indoors, how long is the vent length?
6. If installed outdoors, what type of vent cap is used?
7. Are there any obstructions in the intake air and/or exhaust?
・Damper sticking.
・Vent Flaps installed on the Terminator.
・Snow build up around Terminator.
・Installed in a closet. (No Ventilation or lack of combustion air)
8. If installed in laundry room, check the burner and heat exchanger. Dust and lint may deposit in
burner and heat exchanger.
9.
If installed in restaurant, check the burner and fan motor. Grease and dirt may deposit in burner
and fan motor.
10. Check if the manifold pressure of the water heater is too high.
B.
How to clear the “101” and “991” error code (after resolving the main root cause of the error):
On the computer board, press and hold the “Increase” or “Decrease” buttons simultaneously for at
least 3 seconds until the red light turns on. Then press reset button on the GFI. The “101” and
“991” error code should then be cleared.
Red light
Increase button
Decrease button
51
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-4. AFR rod function
<Function>
The AFR rod checks flame conditions during combustion. When the AFR rod detects unexpected flame
conditions, the computer board of the T-M32 adjusts the fan motor speed to ensure that air and fuel are
always at a proper mixture ratio, minimizing emissions.
<AFR normal range of values>
(Unit: μA)
Gas type
LPG
Installation
Outdoor
Natural gas
Indoor
Direct vent
Outdoor
Indoor
Direct vent
Combustion
MAX
2 to 18
2 to 19
2 to 17
4.5 to 22
4 to 22
4 to 22
mode
MIN
1.6 to 23
1.5 to 23
1.4 to 22
1.4 to 18
1.4 to 18
1.4 to 16
・If the AFR value is higher than the normal value, the FM speed is increased.
・If the AFR value is lower than the normal value, the FM speed is decreased.
・Measure the values after burning the water heater for ten minutes.
・These values are read with the front cover close.
*The AFR stage can be confirmed in “Diagnostic Mode”. (Section 12-1)
<The relationship between the AFR stage and the “101” and “991” error codes>
Stage
16
“991” error code
+13.5%
15
“101” error code
・・・・・・・・・・・・・・
6
-9%
0
・・・・・・・
・・・・・・・・・
0%
・・・・・・・・・・・・・・
FM
+15%
(Condition of AFR stage)
・0 to 5: Air-rich
・In order to solve the “air excess” problem, the fan motor
speed is automatically decreased and AFR combustion
stage goes down.
・6: Default
・7 to 16: Gas-rich or Air shortage
・In order to solve the “air deficiency” problem, the fan
motor speed is automatically increased and AFR
Default condition
combustion stage goes up.
・15: “101” error code
・16: “991” error code
・When the “101” or “991” error code appears, see section
12-3.
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12-5. Dipswitch settings
Right bank of
dipswitches
The T-M32 shares the computer board with the T-M32
ASME. There are two banks of dipswitches (right and left
bank) on the T-M32 computer board. The right bank has
certain special functions as shown on the following table
and generally should not need adjustment. Carefully
verify the functions of each dipswitch before changing any
Left bank of
settings.
dipswitches
The functions of the right dipswitch bank
No.
Functions
ON position
OFF position
1
Gas type
Propane
Natural gas
2
FM+ (FM speed is increased automatically. See section +7.5% FM-speed
Disable
12-12)
(Default)
3
4
INPUT-
(Maximum
gas
input
is
reduced -10%
Disable
automatically. See section 12-12)
Maximum input
(Default)
Allow adjustments of fan motor speed
Enable
Disable
(Default)
(Changing the FM speed is similar to changing the
manifold pressure. See section 12-16)
5
Allow access to operation history
EEPROM
data Disable
(This switch is for a specialized purposes only, and transfer
(Default)
therefore, should not be used)
N
O
Storage Tank
Circulation
Control
Activation of the fan motor freeze protection Enable
system
53
LP
FM
EEPROM
RE-CIR
STORAGE
LP
FM
EEPROM
RE-CIR
STORAGE
Disable
(Default)
12 3 4 5 6 7 8
FM
EEPROM
RE-CIR
STORAGE
Normal
Control
(Default)
12 3 4 5 6 7 8
8
LP
12 3 4 5 6 7 8
FM
EEPROM
RE-CIR
STORAGE
12 3 4 5 6 7 8
LP
Energy
Conserving
Recirculation
N
O
Recirculation
Control
7
N
O
Pump mode
N
O
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T-M32 / T-M32 ASME Service Manual
Ver. 1.03
The functions of the left dipswitch bank
No.
Functions and Dipswitch settings
1
Output temperature settings
2
(See the table below)
3
(Default 120 °F)
100 F 115 F 120 F 135 F 145 F 155 F 165 F 185 F
N
O
N
O
N
O
N
O
N
O
N
O
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
D-PRT
MST
No.
Functions
ON position
OFF position
4
Activation of Individual operation mode
Enable
Disable
See Section 12-11
(Default)
Direct vent setting
Enable
Disable
Direct vent mode
(Default)
Enable
Disable
Outdoor mode
(Default)
5
6
Outdoor setting
7
The number of priority combustion unit in a T-M32
Two priority units
8
Parent /Child setting on Easy-link systems
Parent
One priority unit
Child
(Default)
54
1 2 3 4 5 6 7 8
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
D-PRT
MST
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
TMP1
TMP2
TMP3
MODE
DIRE
OUT
1 2 3 4 5 6 7 8
D-PRT
MST
1 2 3 4 5 6 7 8
TMP1
TMP2
TMP3
MODE
DIRE
OUT
(49 C)
(57 C) (63 C) (68 C) (74 C) (85 C)
DEFAULT
N
O
N
O
(38 C) (46 C)
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-6. Assigning unit numbers in the Easy-link system
A. How to display the unit number
Press the “Unit # display” button on the computer board. The 7-seg LED will then display the
assigned number for that T-M32 unit for 10 sec.
NOTE: In a single-unit installation, the numbering system is disabled.
B.
How to reset and reconfigure the numbering of units
Unit #’s can be reset and reassigned manually:
1. Press and hold the “Unit # display” button on the computer board of all child units for at least 5
seconds.
2. The 7-seg LED on the computer board of all child units will display “0” to signify that the computer
memory has been erased of its previously assigned unit #.
3. Press and hold the "Unit # display" button again. New unit # will be assigned in order as you
proceed through every unit.
Each T-M32 in an Easy-link system is assigned a random unit #, except for
the Parent unit, which is always assigned as unit #1.
When more than four units of the T-M32 are connected in an Easy-link
system, only the first four units will work as a system. The remaining units
will not operate.
Unit # display button
7-seg LED
Computer board
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12-7. (A) ON/OFF conditions: Overview
The following table shows the ON/OFF conditions of the water heater.
ON / OFF Conditions
For Every pump modes
The BTU requirement is more than 14,880 BTU/h
Conditions needed to turn ON.
AND
The water flow rate is more than 0.5 GPM
The BTU requirement is less than 11,900 BTU/h
OR
Inlet temperature is higher than the set
Conditions needed to turn OFF.
temperature
OR
Output temperature is over 194°F
OR
The water flow rate is less than 0.4 GPM
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12-7.(B) ON/OFF conditions: BTU requirements
A. Calculating the ON/OFF conditions of the T-M32
【Condition needed to turn the T-M32 ON】
(Tset – Tin) × GPM × 500 > 14,880
【Condition needed to turn the T-M32 OFF】
(Tset – Tin) × GPM × 500 <11,900 or Tin = Tset
Where: Tset = Set temperature and Tin = Inlet temperature
B. Calculation example
Set temperature: Tset = 120˚F
Flow rate = 2.5 GPM
【Condition needed to turn the T-M32 ON】
(120 – Tin) × 2.5 × 500 > 14,880
Tin < 108.1˚F
【Condition needed to turn the T-M32 OFF】
(120 - Tin) × 2.5 × 500 < 11,900
Tin > 110.5˚F
The outlet temperature at that moment will be 120˚F
C. ON/OFF table
Set temperature
(˚F)
100
115
120
135
145
155
165
185
Flow rate (GPM)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
ON
40.5
70.2
80.2
85.1
88.1
90.1
91.5
92.6
OFF
52.4
76.2
84.1
88.1
90.5
92.1
93.2
94.1
ON
55.5
85.2
95.2
100.1
103.1
105.1
106.5
107.6
OFF
67.4
91.2
99.1
103.1
105.5
107.1
108.2
109.1
ON
60.5
90.2
100.2
105.1
108.1
110.1
111.5
112.6
OFF
72.4
96.2
104.1
108.1
110.5
112.1
113.2
114.1
ON
75.5
105.2
115.2
120.1
123.1
125.1
126.5
127.6
OFF
87.4
111.2
119.1
123.1
125.5
127.1
128.2
129.1
ON
85.5
115.2
125.2
130.1
133.1
135.1
136.5
137.6
OFF
97.4
121.2
129.1
133.1
135.5
137.1
138.2
139.1
ON
95.5
125.2
135.2
140.1
143.1
145.1
146.5
147.6
OFF
107.4
131.2
139.1
143.1
145.5
147.1
148.2
149.1
ON
105.5
135.2
145.2
150.1
153.1
155.1
156.5
157.6
OFF
117.4
141.2
149.1
153.1
155.5
157.1
158.2
159.1
ON
125.5
155.2
165.2
170.1
173.1
175.1
176.5
177.6
OFF
137.4
161.2
169.1
173.1
175.5
177.1
178.2
179.1
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-8. (A)Pump control ON / OFF Conditions (Only for single and Easy-link system)
To run circulation pumps efficiently and effectively, the T-M32 offers four different modes of pump
control. The following table shows the pump control ON/OFF conditions for different modes. To change
pump control modes, see section 12-5 for dipswitch settings.
“Normal mode” and “Storage tank circulation mode”
There are no specific ON/OFF conditions for these two modes. The circulation pump will receive a
constant “ON” signal from the pump terminal on the computer board, and will run continuously.
“Re-circulation mode” and “Energy conserving re-circulation mode”
These functions enable the re-circulation pump to be controlled by the following conditions.
ON/OFF Conditions
Re-circulation mode
Energy conserving re-circulation mode
The BTU requirement is more than Inlet water temperature is less than
14,880 BTU/h*
95°F(35°C) and flow rate is less than
Conditions that activate
OR
0.8GPM
the pump
30 minutes have elapsed after
previous operation
OR
20 minutes have elapsed after previous
operation
5 minutes after activation, if the
Conditions that
deactivate the pump
computer detects a BTU
requirement of less than 14,880
BTU/h, the computer will stop the
pump in 90 seconds.
1 minute after activation, if the
computer detects a BTU requirement of
less than 14,880 BTU/h, the computer
will stop the pump in 75 seconds.
*The computer records the inlet temperature and the flow rate of the pump during the final minute of
its previous operation when calculating the BTU requirement.
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12-8. (B) Pump control ON/OFF conditions: BTU requirements for Re-circulation
mode
A. Calculating the ON/OFF conditions of the pump
【Condition needed to turn the pump ON】
( Tset – Tin ) × GPM × 500 > 14,880
【Condition needed to turn the pump OFF】
5 minutes after activation, if the computer detects a BTU requirement of less than 18,600 BTU/h, the
computer will stop the pump 90 seconds.
( Tset – Tin ) × GPM × 500 < 14,880 or Tin = Tset
Where: Tset = Set temperature and Tin = Inlet temperature
B. Calculation example
Set temperature: Tset = 120 ˚F
Flow rate = 2.5 GPM
【Condition needed to turn the pump ON】
( 120 – Tin ) × 2.5 × 500 > 14,880
Tin < 108.1˚F
【Condition needed to turn the pump OFF】
( 120 – Tin ) × 2.5 × 500 < 14,880
Tin > 108.1˚F
C. ON/OFF table (ON values are the same as OFF values)
Set temperature
Flow rate (GPM)
(˚F)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
100
40.5
70.2
80.2
85.1
88.1
90.1
91.5
92.6
115
55.5
85.2
95.2
100.1
103.1
105.1
106.5
107.6
120
60.5
90.2
100.2
105.1
108.1
110.1
111.5
112.6
135
75.5
105.2
115.2
120.1
123.1
125.1
126.5
127.6
145
85.5
115.2
125.2
130.1
133.1
135.1
136.5
137.6
155
95.5
125.2
135.2
140.1
143.1
145.1
146.5
147.6
165
105.5
135.2
145.2
150.1
153.1
155.1
156.5
157.6
185
125.5
155.2
165.2
170.1
173.1
175.1
176.5
177.6
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-9. Multi-unit system ON / OFF conditions
In Easy-link system and Multiple-system, the amount of T-M32’s called on to activate depends on the
FLOW RATE and the SET TEMPERATURE.
1. Condition required to activate an additional T-M32:
Flow rate required to activate additional T-M32 = A × n
Where n= number of currently activated T-M32’s
and A is dependent on the set temperature. See table below:
Set temperature
Factor "A"
˚F
˚C
GPM
L/min
100 - 120
38 - 49
3.4
13
125,130
52 - 54
3.2
12
140
60
2.9
11
145,150
63 - 65
2.6
10
155 - 185
68 - 85
2.4
9
2. Condition required to reduce the number of activated T-M32’s:
A. In the case of reducing down from two units T-M32’s to one T-M32: Flow rate = A / 1.7
B. All other cases: Flow rate = A × (n - 2)
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3. Example: Set temperature = 120˚F in a 20-unit system and priority unit is No. 1
(See the table below)
To activate additional T-M32’s
Unit No.
To reduce number of activated T-M32’s
Flow rate
GPM
L/min
No.1 ON
0.5
1.9
No.2 ON
3
No.3 ON
Unit No.
Flow rate
GPM
L/min
No.20 OFF
62
234
13
No.19 OFF
58
221
7
26
No.18 OFF
55
208
No.4 ON
10
39
No.17 OFF
52
195
No. 5 ON
14
52
No.16 OFF
48
182
No. 6 ON
17
65
No.15 OFF
45
169
No. 7 ON
21
78
No.14 OFF
41
156
No. 8 ON
24
91
No.13 OFF
38
143
No.9 ON
27
104
No.12 OFF
34
130
No.10 ON
31
117
No.11 OFF
31
117
No.11 ON
34
130
No.10 OFF
27
104
No.12 ON
38
143
No.9 OFF
24
91
No.13 ON
41
156
No.8 OFF
21
78
No.14 ON
45
169
No.7 OFF
17
65
No.15 ON
48
182
No.6 OFF
14
52
No.16 ON
52
195
No.5 OFF
10
39
No.17 ON
55
208
No.4 OFF
7
26
No.18 ON
58
221
No.3 OFF
3
13
No.19 ON
62
234
No.2 OFF
2.0
7.6
No.20 ON
65
247
No.1 OFF
0.4
1.5
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-10. Operation time for unit rotation
The unit that turns on first is whichever unit the T-M32 decides is the primary unit.
The priority unit will rotate when it reaches 100 ON / OFF cycles or after 12 hours of operation.
NOTE: The priority unit is the unit that turns on first when there is a hot water demand.
When there is a black out and/or cut off for over 50 minutes, priority unit will switch back to
Unit #1.
Example: Four units of T-M32s Rotation
A rotation occurs when:
ON/OFF cycles (×100 times) or Hours of operation (12 hours)
Priority Unit
Unit
Unit
Unit
Unit
No.1
No.2
No.3
No.4
1
2
3
4
2
3
1
2
Next step
Priority Unit
4
1
Next step
Priority Unit
3
4
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T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-11. Individual unit operation in multiple-system while multi-unit controller
(TM-MC01) is under abnormal conditions (Individual operation mode)
A multi-unit system of T-M32s requires the multi-unit controller. If the multi-unit controller undergoes
abnormal conditions, the T-M32s can operate as individual units. If this happens, the minimum flow
rate of the system changes from 0.5 GPM to 0.5 GPM multiplied by the number of T-M32s. Refer to the
following example:
Ex: Minimum flow rate of a five unit multi-unit system.
Under normal conditions: 0.5GPM
When the multi-unit controller fails: 0.5×5=2.5GPM
Minimum flow rate of the multiple-system depends on the number of the units installed in the
multiple-system.
The set temperature of the units as individual units is the set temperature before the failed
communication happened between T-M32 and the multi-unit controller.
T-M32s will not work individually during with a failed the multi-unit controller if the “Individual
operation mode” is disabled. See section12-5 “Individual operation mode” in Dipswitch settings of
the computer board
In order to make operation system effective during an abnormal condition, the number of individual
unit should be half of the total number of T-M32 installed in multiple-system.
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T-M32 / T-M32 ASME Service Manual
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12-12. High-Altitude Region Support Functions (FM+ and INPUT-)
<Using this function>
The high-altitude region support functions have three operation levels,
with the appropriate level being set up by the installer until the abnormal
sound problem is solved. The desired level can be specified at the right
bank of dipswitches (No.2 and No.3) on the computer board.
Level
0
1
2
Function
Standard setting
Setting Method
Right bank of dipswitches No.2 OFF
(Default)
the fan motor speed increased
No.3 OFF
Right bank of dipswitches No.2 ON
by 7.5% (FM+ function)
Reduction of the max gas input
Right bank of dipswitches
No.3 OFF
Right bank of dipswitches No.2 OFF
by 10% (INPUT- function)
No.3 ON
the fan motor speed increased
by 7.5% (FM+ function)
3
&
Right bank of dipswitches No.2 ON
No.3 ON
Lowers the max. input by 10%
(INPUT- function)
If the abnormal sound problem persists even with a “Level 3” setting, please contact our
Technical Service Department. for advice. Note that there are many high risks associated with
CAUTION
manually changing the manifold pressures.
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T-M32 / T-M32 ASME Service Manual
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12-13. Checking the Flow Rate by Computer Board
<Function>
This function offers a method for checking the flow rate in the water heater’s troubleshooting operations
without having to use the remote controller.
The flow rate check is performed simply by using the “7-Seg LED” on the computer board and the
“Increase” button. The procedure given below can be used to indicate the current flow rate (detected by
the flow sensor) at the “7-Seg LED”. The LED can only display a flow rate range, but this function is
nonetheless useful for the computer board and flow sensor diagnostic purposes.
7-Seg LED
<Using the function>
1. When in Standby mode right before ignition (cannot be in
combustion, forced-combustion, or the FM adjustment
modes), press and hold the “Increase” button for 5 seconds
or longer to start a display of “A” at “7-seg LED”. Press the
“Increase” button a few times to change the display to “d”.
2. While “d” is displayed, press the “Number display”
button to display the flow rate.
The values displayed at the “7-seg LED” and their
corresponding flow rates are shown in the table below.
“Increase” Button
7-seg LED display
Flow rate detected by flow sensor
[GPM]
0
0 to 0.4
1
0.5 to1.4
2
1.5 to 2.4
3
2.5 to 3.4
4
3.5 to 4.4
5
4.5 to 5.4
6
5.5 to 6.4
7
6.5 to 7.4
8
7.5 to 8.4
9
8.5 or higher
65
“Number display” Button
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-14. Relay selection for the pump control connection
The maximum current capacity of the T-M32’s
pump control connection is 1 amp.
Before using relay with the pump control, please
check the specifications of that particular relay to
ensure that the current value through the coil will
not exceed 1 amp.
For example
To the right, there is a sample of relay
specifications from an arbitrary brochure. You
can select either the 120 VAC or 240 VAC relay,
because their current values are less than 1 A
(1,000 mA).
Power supply for relay
Through this circuit, the maximum current
Normally 120 VAC
capacity is 1 A
Power supply for pump
120 VAC
220 VAC etc
120 VAC
220 VAC etc
Thermal relay
Recirculation
pump
These components are not included with water
heaters and are external to the unit.
Connect to this “Pump” connector.
must be acquired separately.
66
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-15. Adjusting manifold gas pressure
The manifold gas pressure on the T-M32 can be adjusted by following the procedures below.
Adjusting the manifold pressure can cause unexpected combustion conditions during
operation, which can cause a health hazard, damage the T-M32, and/or shorten its lifespan.
Therefore, changing the manifold pressure is not recommended unless there are very
WARNING
strong reasons to do so (e.g. high elevation installations), and with the consultation of the
Technical Services Department.
Adjusting maximum manifold pressure
1. Ensure that T-M32 do not in operation.
2. Remove the screw off the manifold port of the T-M32. (Figure 1)
3. Connect a manometer to the manifold port using a tube (Figure 2). Ensure that this connection is
secure enough to prevent gas leak.
4. Run water through the T-M32 to activate its operation. If presence of a gas leak is detected,
immediately shut off the T-M32 and inspect the tube / manifold connection; otherwise, proceed
onto the next step.
5. Press and hold down the “MAX” button on the computer board. While holding down the “MAX”
button, press either the “Increase” or “Decrease” button to increase or decrease the manifold gas
pressure, respectively (Figure 3). Refer to the manometer to verify that pressure has been set to
desired value.
6. After gas pressure has been set, deactivate the T-M32, remove the manometer tube, and replace the
port screw.
Adjusting minimum manifold pressure
1. Ensure that T-M32 do not in operation.
2. Remove the screw off the manifold port of the T-M32. (Figure 1)
3. Connect a manometer to the manifold port using a tube (Figure 2). Ensure that this connection is
secure enough to prevent gas leak.
4. Run water through the T-M32 to activate its operation. If presence of a gas leak is detected,
immediately shut off the T-M32 and inspect the tube / manifold connection; otherwise, proceed
onto the next step.
5. Press and hold down the “MIN” button on the computer board. While holding down the “MIN”
button, press either the “Increase” or “Decrease” button to increase or decrease the manifold gas
pressure, respectively (Figure 3). Refer to the manometer to verify that pressure has been set to
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Ver. 1.03
desired value.
6. After gas pressure has been set, deactivate the T-M32, remove the manometer tube, and replace the
port screw.
Figure 1
Manifold port
Figure 2
Figure 3
Tube
MAX button
MIN button
Increase button
Decrease button
Computer board
To Manometer
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T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-16. Manually adjusting the fan motor speed
While the FM+ dipswitch will automatically increase the fan speed by 7.5%, the fan motor speed on
the T-M32 can also be manually adjusted. In order to perform manual adjustments to the speed, a
remote controller is required.
WARNING
Manually adjusting the fan motor speed of the T-M32 will change the amount of intake air
for combustion, which can cause excess CO emission from the exhaust chamber if the fan
motor speed is set incorrectly. Therefore, this procedure should never be performed
unless the Technical Services Department has given consent and authorization.
Adjusting maximum fan motor speed
1. While T-M32 is in operation, set dipswitch No.4 on T-M32 computer board to the “ON” position.
(Figure 1)
2. On the temperature remote controller, display mode #3 (fan motor speed) by entering the
“Diagnostics mode” (Refer to Section 12-1).
3. Press and hold down the “MAX” button on the computer board. While holding down the “MAX”
button, press either the “Increase” or “Decrease” button to increase or decrease the fan motor speed,
respectively (Figure 2). Refer to the remote controller display to verify that speed has been set to
desired value.
4. After fan speed has been set, set dipswitch No.4 back to the “OFF” position.
Adjusting minimum fan motor speed
1. While T-M32 is in operation, set dipswitch No.4 on T-M32 to the “ON” position. (Figure 1)
2. On the temperature remote controller, display mode #3 (fan motor speed) by entering the
“Diagnostics mode” (Refer to Section 12-1).
3. Press and hold down the “MIN” button on the computer board. While holding down the “MIN”
button, press either the “Increase” or “Decrease” button to increase or decrease the fan motor speed,
respectively (Figure 2). Refer to the remote controller display to verify that speed has been set to
desired value.
4. After fan speed has been set, set dipswitch No.4 back to the “OFF” position.
Figure 2
N
O
Figure 1
FM
EEPROM
RE-CIR
STORAGE
12 3 4 5 6 7 8
LP
Right bank of dipswitches
Right bank of dipswitches
MAX button
MIN button
Increase button
Decrease button
69
Computer board
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T-M32 / T-M32 ASME Service Manual
Ver. 1.03
12-17. Freeze protection system
There are two features to the T-M32’s freeze protection system: the automatic fan motor system and the
ceramic heating blocks. The automatic fan motor system allows the T-M32 to briefly do fan motor
operation and the ceramic heating blocks will heat up whatever portion of the heat exchanger the blocks
are strapped to.
The automatic fan motor mainly focuses on providing freeze protection from the back flow of the
venting. The seven heating blocks focus on protecting the inlet and outlet piping inside the T-M32, as
well as the front drum pipe. The conditions to activate either feature are different from each other.
However, the two features are not mutually exclusive, because they focus on different areas of the
T-M32. As long as each particular feature’s activation requirements are met, it is possible for both
features to operate at the same time
Ceramic heating blocks
The blocks will only activate based on what the freeze protection thermostat senses. The thermostat is
located on the fan motor. Electrical power is required for this feature to operate.
The heating blocks will activate if the thermostat senses a surrounding temperature below 36.5°F.
Once they are on, the heating blocks will only deactivate if surrounding temperatures reach above
46.4°F.
Automatic fan motor system
This feature is for only Indoor installation.
Electrical power is required for this feature to operate.
The computer will continually check the temperatures of the inlet, outlet and mixing
thermistors.
Automatic fan motor will not work if the “Activation of the fan motor freeze protection system”
is disabled. See section12-5.
<Activate condition>
When the computer checks for these temperatures, the Automatic fan motor system will activate if:
Tout < 46°F
AND
Tout < Tin - 5°F
where Tin is the temperature of inlet thermistor and Tout is the temperature of the output thermistor.
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<Deactivate condition>
When the computer checks for these temperatures during the fan motor operation as freeze
protection, the Automatic fan motor system will deactivate if:
Tout > Tin + 3.6°F
OR
Tin > 50°F and Tout > 50°F and TMIX > 50°F
OR
Tin > 39°F and Tout > 39°F and TMIX > 39°F and “Flow sensor detects flow rate for 1min”
where Tin is the temperature of inlet thermistor and Tout is the temperature of the output
thermistor and TMIX is the temperature of the mixing thermistor.
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12-18. Freeze protection for recirculation systems
<Function and Purpose>
The T-M32 has the freeze protection function for a re-circulation system by using a pump installed in the
system. Basically, this function is only ON / OFF control of the pump from the computer in the T-M32.
When the computer detects the potential of the system freezing, the pump in the system starts
automatically.
To use this function in Easy-link system, the pump must be connected to the pump control
port in the computer board of the Parent unit. Refer to Section 12-17 for details.
< While recirculation system freeze protection is in operation>
While this freeze protection is operating, the computer will display “P” on its 7-seg LED,
however, the remote controllers will not display anything on its screen.
In order to detect the temperature of the system accurately, The computer makes the pump
work every two minutes during the freeze protection operation
A. Activation conditions (all 3 conditions must occur):
1. Please follow the procedure on the next page.
2. The T-M32 is in non-operation (no call for hot water).
3. The computer (of the parent unit) detects water temperature 50°F (10°C) or below (the computer
will activate the pump every two minutes to properly measure water temperatures throughout the
recirculation line).
When T-M32 is NOT connected to the remote controller, Change the dipswitch No.4 (the
left bank) on the computer board to the “OFF” position.
B.
Computer board
Deactivation condition:
After pump has been activated for freeze
protection, the pump is set to run for at least 1
hour. After 1 hour has elapsed, the computer
(of the parent unit) will actively measure water
temperature.
Pump will deactivate if
temperatures remain above 50°F (10°C)
continuously for 10 minutes.
Left bank of dipswitches
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<Freeze Protection pump setting mode>
To set the Freeze protection pump mode in T-M32, please follow the procedures below:
1. While in Standby mode (cannot be in combustion, forced-combustion, or FM adjustment modes),
press and hold the “Increase” button for 5 seconds or longer to start a display of “A” at “7-seg LED”
on the computer board.
2. While “A” is displayed, press the “Number display” button.
The “7-seg LED” will display “o”…”F”…”F”, and then repeat the 3 letters. (“oFF” signifies the default
setting)
3. While “oFF” is blinking, press the “Number display” button again.
The “7-seg LED” will display “o”…”n”, and then repeat the 2 letters.
4. While “on” is blinking, press the “Increase” button to fix the setting.
“b” will then be displayed.
5. Press the “Decrease” button to finish the setting.
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12-19. Draining the unit and cleaning the inlet water filter
1. Close the manual gas shut off valve.
2. Turn off power to the T-M32, wait a few seconds. And then turn on again.
3. Wait 30 seconds for water valves starts to completely open.
Then turn off power to the T-M32, yet again.
4. Close the water shut off valve.
5. Open all hot water taps in the house. When the all
water flow has ceased, close all hot water taps.
6. Have a bucket or pan to catch the water from the
drain plugs of the T-M32. Unscrew the drain plugs to
drain all the water out of the T-M32.
7. Wait a few minutes to ensure all water has completely
drained from unit.
8. Clean the filter: Inspect the water filter located within
the cold inlet. With a tiny brush, clean the water filter
of any debris which may have accumulated and
reinsert the filter back into the cold water inlet.
9. Securely screw the drain plugs back into place. Handtighten only.
74
Drain Plug
Water Valve
Drain
with Filter
Gas Valve
Plug
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
13. Components diagrams
Case assembly
0 52
702
0 51
0 51
00 4
0 52
003
050
001
005
0 10
011
007
051
0 52
00 7
0 04
052
006
050
00 2
052
008
703
052
Computer board assembly
Other than Part# 706, the T-M32 and the
T-M32
ASME
share
the
same
components.
05 2
716
052
715
05 2
7 08
052
714
71 8
717
712
42 3
70 1
7 19
7 19
713
70 5
7 07
7 06
705 :F or T- M32
705:
706 :FFor
or T-M32
T- M32 AS ME
706: For T-M32 ASME
052
7 03
711
70 4
1 15
710
720
70 3
75
70 9
0 52
70 8
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Burner assembly
The T-M32 and theT-M32 ASME share the same components.
103
102
101
40 1
113
152
153
707
152
1 05
104
114
152
112
115
152
106
152
111
154
116
118
107
151
108
109
117
110
119
12 1
152
152
152
124
70 4
159
120
125
122
704
156
159
123
157
158
76
155
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Other than Part# 211, Part#439, Part#440 and Part# 441, the T-M32 and
the T-M32 ASME share the same components.
Water way assembly
T-M32
401
414
420
423
420
414
he
ge r
T o t e xc h a n
He at
431
402
405
150
436
432
420
414
414
429
426
414
425
430
403
2 10
424
433
150
428
4 14
427
4 21
4 19
419
422
420
419
435
427
434
404
437
418
414
416
405
415
417
413
414
412
409
052
411
052
410
408
4 07
406
T-M32 ASME
414
4 23
420
414
40 1
A
420
43 1
40 2
405
150
420
43 2
40 3
436
43 3
21 1
4 14
419
4 14
4 29
4 26
434
4 14
4 24
4 25
4 28
43 9
150
4 14
4 40
434
42 2
40 4
42 0
419
41 9
4 27
437
435
40 5
427
418
43 7
414
416
4 13
414
417
415
41 4
41 2
44 1
A
0 52
411
0 52
4 10
409
40 8
77
407
406
CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
14. Parts list
Item #
Part #
Description
Common parts for other models
1
EM389
Case assembly
2
EM431
Front cover
3
EM386
Air blockage plate
4
EM104
Bracket
5
EM384
Back guard panel
6
EKJ64
Junction box
7
EX00E
Fixing plate
8
EX00B
Rubber bush
10
EM484
11
EKK22
Fastener
T-H2-DV/OS
51
EW001
Screw M4×10 (W/Washer)
*
52
EW002
Screw M4×10 (Coated)
*
101
EM410
Burner assembly
102
EM411
Burner gasket
103
EM412
Guide plate gasket
104
EKK2V
Burner window
105
EKK2W
Rod holder gasket
106
EKK0E
Flame rod
107
EKK32
Rod holder
108
EKK0F
Igniter rod
109
EKN61
Rod cap
110
EX01Z
High voltage ignite cable
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-M50
Overheat-cut-off-fuse for
T-H2-DV/OS
combustion chamber
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
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CONFIDENTIAL
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Ver. 1.03
Item #
Part #
110
EX01Z
High voltage ignite cable
111
EM409
Damper
112
EX02C
Urethane tube
113
EKK2D
Pressure port
114
EM379
Fan motor fixing plate
115
EKK25
Fan motor
116
EM381
Fan damper
117
EKJ59
Freeze protection thermostat
118
EM435
Manifold gasket A
119
EX00F
Manifold gasket B
EM440
120
EM441
Description
Common parts for other models
T-K3, T-K3-Pro, T-K3-SP, T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP, T-H2-DV/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP, T-KJr2-IN/OS,
T-K4-IN/OS, T-D2-IN/OS
Manifold assembly with gas valve
assembly LP
Manifold assembly with gas valve
assembly NA
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
121
EM167
Wire cramp 60
122
EX00D
Gas inlet ring
123
EM442
Gas inlet
124
EKK1B
Igniter plate
125
EKN74
Igniter
151
EW00D
Pan screw M4×8
*
152
EW003
Screw M4×10
*
153
EW00H
Pan screw M4×12 (W/Washer)
*
154
EW00B
Screw M3×6
*
155
EW008
Screw M3×10
*
156
EZP26
O-ring P26 NBR (Black)
157
EW006
Pan screw M4×10
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
*
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Item #
Part #
Description
Common parts for other models
158
EW001
Screw M4×10 (W/Washer)
*
159
EW005
Hex head screw M4×8
*
160
EW00L
Pan screw M4×6 (W/Washer)
*
210
EM415
Heat exchanger assembly for T-M32
211
EM45C
401
EKN50
Silicon ring
402
EKK26
Fuse fixing plate 18
403
EM387
Overheat-cut-off-fuse
404
EKN86
Pipe heater 122
405
EKK27
Heater fixing plate
406
EM222
Filter plug
T-H2-DV/OS, T-M50
407
EZM25
O-ring P25 EPDM (Purple)
T-H2-DV/OS, T-M50
408
EX006
Water inlet filter
T-H2-DV/OS, T-M50
409
EZN21
O-ring JASO# 1021 EPDM (Purple)
T-H2-DV/OS, T-M50
410
EX002
Heater 101
T-H2-DV/OS, T-M50
411
EM404
Water inlet
T-H2-DV/OS
412
EZN16
O-ring JASO# 1016 EPDM (Purple)
T-H2-DV/OS
413
EX021
Heater plate
T-H2-DV/OS, T-M50
414
EX01H
Fastener “16AG”
T-H2-DV/OS, T-M50
415
EKK2P
Inlet heater
416
EK239
Outlet drain plug
417
EZM06
O-ring P6 EPDM (Purple)
418
EX00H
Mixing thermistor
Heat exchanger assembly for T-M32
ASME
T-K3, T-K3-Pro, T-K3-SP, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-H2-DV/OS
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-H2-DV/OS
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Item #
Part #
Description
Common parts for other models
419
EZM04
O-ring P4 EPDM (Purple)
420
EZM16
O-ring P16 EPDM (Purple)
421
EM390
Cold pipe
422
EKK38
Inlet thermistor
T-K3, T-K3-Pro, T-H2-DV/OS, T-D2-IN/OS, T-M50
423
EKH32
Water control valve
T-H2-DV/OS, T-M50
424
EW00A
Screw M3×6
*
425
EK031
Heater fixing plate 16
426
EM45V
Pipe heater 212
427
EW00L
Pan screw M4×6 (W/Washer)
428
EZM15
O-ring P15 EPDM (Purple)
429
EKH33
Flow sensor
430
EM391
Hot pipe
431
EM45G
L joint
432
EKN34
Hi-limit switch
433
EKK2T
Output thermistor
T-K3, T-K3-Pro, T-H2-DV/OS, T-D2-IN/OS, T-M50
434
EKH30
Fastener “4-11”
T-K3, T-K3-Pro, T-H2-DV/OS, T-D2-IN/OS, T-M50
435
EKJ02
Water outlet
T-H2-DV/OS
436
EZN17
O-ring JASO# 1017 EPDM (Purple)
T-H2-DV/OS
437
EZM18
O-ring P18 EPDM (Purple)
T-M50
439
EM45E
Hot pipe for T-M32 ASME
440
EM45D
Cold pipe for T-M32 ASME
441
EM45F
Connection pipe for T-M32 ASME
701
EM376
T-M32 PCB
702
EM454
Transformer
703
EM463
Junction box inner plate
704
EM392
Gas valve wire
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-H2-DV/OS, T-KJr2-IN/OS, T-K4-IN/OS,
T-D2-IN/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS, T-M50
T-H2-DV/OS, T-M50
T-K3, T-K3-Pro, T-K3-SP/OS, T-H2-DV/OS,
T-D2-IN/OS, T-M50
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CONFIDENTIAL
T-M32 / T-M32 ASME Service Manual
Ver. 1.03
Item #
Part #
705
EM396
Description
Common parts for other models
“Flow sensor, Gas proportional valve
connection and Thermistors” wire
“Flow sensor, Gas proportional valve
706
EM479
connection and Thermistors” wire
for T-M32 ASME
707
EM395
Flame rod wire
708
EC00X
Nylon clamp
709
EM45T
Igniter & Freeze protection wire
710
EM393
AC100V wire
711
EM403
AC100V Transformer connecting wire
T-H2-DV/OS
712
EM207
Ground fault circuit interrupter
T-M50
713
EM400
Power supply code assembly
714
EM399
AC120V Transformer connecting wire
715
EM385
Surge box
716
EM377
PCB fixing plate
717
EM398
Remote controller terminal
718
EW00X
Screw M3×12
719
EX013
Screw M4×12
720
EM478
PCB cover
T-K3,
T-K3-Pro,
T-K3-SP/OS,
T-H2-DV/OS,
T-KJr2-IN/OS, T-K4-IN/OS, T-D2-IN/OS
T-M50
T-M50
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Ver. 1.03
15. Records of revision of this manual
Version
Changes
Date
1.00
Sample evaluation
06/27/08
1.01
Revised by the R&D and Takagi Japan
12/09/08
1.02
Revised by the R&D and Takagi Japan
02/12/09
1.03
Revised by the R&D and Takagi Japan
11/22/10
83
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