andrews Fastflo WHC56 User manual

Working towards
a cleaner future
FASTflo WHC56
Service Manual
March 2010

March 2010
WHC56
Service Manual
•This manual must be read by Service personnel re-
pairing the above appliance models.
•Ta ke this manual with you when attending Service study
meetings.
•The specifications and contents of this manual may
change at any time without prior notification.
Never short-circuit any safety devices
CONTENTS
Overview of Condensing Gas Water Heater ............................................................... 2
Structural Cross-section of Operation Unit................................................................. 3
Principle of Operation................................................................................................. 4
Operation Panel, Remote Control .............................................................................. 6
Initital Operation ......................................................................................................... 7
Setting Hot Water Temperature .................................................................................. 8
Sequence ................................................................................................................. 10
Wiring Diagram and Inspection Flowchart ............................................................... 12
Checkpoints and Measures if a Breakdown Occurs................................................. 14
Maintenance............................................................................................................. 25
Installation ................................................................................................................ 37
Specifications ........................................................................................................... 39
Dimensions .............................................................................................................. 40
KS-09-0003

– 2 –
Cold water Cold water Gas Gas Hot water Hot water
Condensate
Combustion gas
About 200°C
About 200°C
Exhaust Exhaust
About 50°C
Conventional
type
Condensing
Gas Water
Heater
Water is heated
using the exhaust
gas which is about
200°C
.
Primary heat exchanger
Primary heat exchanger
Secondary heat exchanger
Drain Trap
Combustion gas
About 200°C
The condensing gas water heater
discharges condensate.
When heat from the exhaust gas is collected
within the secondary heat exchanger,
condensation occurs from moisture in the
exhaust gas and the resulting water is
discharged from the drain pipe (approx. 100cc/
min maximum). It is not a water leak. Do not
plug or block the drain line as it must always be
allowed to freely flow.
Drain pipe
(Installation example)
This water heater is a high efficiency, fully condensing appliance. Unlike a traditional water heater, a condensing
type captures heat from the exhaust gas and uses it to preheat the incoming cold water as it passes through the
secondary heat exchanger as illustrated below.
The condensing gas water heater
tends to show white steam.
After the exhaust gas passes through the
secondary heat exchanger, it becomes low in
temperature and moisture rich which tends to
produce steam at the vent discharge terminal.
This is a normal occurrence.
Condensate
comes out from
here.
During combustion, white
steam may often be seen.
This is normal.
Overview of Condensing Gas Water Heater

– 3 –
Structural Cross-section of Operation Unit
< WHC56, LWHC56>
Flue collar
Air inlet
Ignition electrode
PCB
Gas inlet
Flame rod
Igniter
Frost sensing switch
Drain trap
Water level electrode
(Front side:No.2)
(Back side:No.1)
Main flow control valve
Heat exchanger
thermistor
Bypass flow control valve
Fan motor
Water outlet thermistor
Transformer
Hot water outlet
Condensate drain outlet
Water filter Water flow sensor
Water inlet thermistor
Cold water inlet
Power cord
Remote controller
terminal
Current leakage
safety device
Gas proportioning valve
Gas solenoid valve
Manifold
Thermal fuse
High-limit switch
Primary heat exchanger
Secondary heat exchanger

– 4 –
Principle of Operation
PCB
Impeller
Gas
Air Supply
Flame Rod
Ignition Electrode
Igniter
High-Limit Switch
High-Limit Switch
Exhaust
Anti-Frost Heater Frost Sensing Switch
Main Flow Control Valve
Heat Exchanger Thermistor
Bypass Flow Control Valve
Water Inlet
Thermistor
Water Flow Sensor
Water Outlet
Thermistor
Fan Motor
Rotation Frequency Sensor
Transformer
Current leakage
safety device
Water Drain Valve
Hot Water
Supply
Water Supply
Over Pressure Relief Valve
Water Filter
Water Drain Valve
Hot Water
Fixture
Water Drain Valve
AC230V
Water Outlet
(Condensate)
Water Drain Valve
Gas Solenoid Valve 2
Gas Solenoid Valve 1
Gas Solenoid Valve 3
Gas Proportioning Valve
Primary Gas Solenoid Valve
Drain trap SET
Burner
Thermal Fuse
Primary Heat Exchanger
Water Level Electrode 1
Water Level Electrode 2
Secondary Heat Exchanger

– 5 –
Explanation of operation
1.Using hot water
(1) Turn the ON/OFF button on the remote controller to ON.(The ON/OFF button will
turn on the light.)
(2) Open the hot water valve to be used. If the water flow sensor detects a water flow above the mini-
mum operation water flow volume, pre-purge(purging gas remaining in the combustion chamber
before ignition) will be carried out for a fixed duration of time. After this the gas solenoid valve will
open, the ignition device will activate, and ignition will take place in the burner. (The bypass flow
control valve is always waiting in the normally "open" position.)
(3) When the flame rod(flame sensor) detects a flame, the ignition device will stop sparking.
(4) The hot water temperature will automatically be adjusted to the temperature selected with the temp.
button.
(5) Close the hot water valve that was used.
(6) When the water flow sensor detects a water flow below the minimum operation water flow, the gas
solenoid valve will close and the flame will go out. Post-purge(purging gas remaining in the com-
bustion chamber after the flame goes out) will be carried out for a fixed duration of time, and then
the unit will stop.
(7) After using, the ON/OFF button on the remote controller should be turn OFF.
(The ON/OFF button will turn off the light.)
2. Error Codes
If by any chance the flame rod does not detect a flame or the high limit switch activates, the gas sole-
noid valve will close and extinguish the flame.
The display will show an error message to inform you of safe operation.
The safe operation reset procedure is to press the ON/OFF button so it turns OFF, and then
press it again to turn it ON.
3. Miscellaneous
Before going to bed or at other times when the unit will not be used for a prolonged period of time, be
sure to press the ON/OFF button on the remote controllers, make sure that the display has
gone off, and then close the primary gas solenoid valve.

– 6 –
Main Remote Controller (RC-7508M)
Part number B285
Display
Set Button
Speaker
Power On/Off Button / Lamp
Selection Button
Operation Panel, Remote control
PLEASE NOTE THAT ONE REMOTE CONTROLLER IS REQUIRED PER INSTALLATION

– 7 –
Before the first use of your water heater, make the following preparations.
Follow steps 1 through 4.
1Open the water supply valve.
Open a hot water fixture to confirm that
water is available, and then close the fixture
again.
3Open the gas supply valve.
Hot water fixture
2
Turn on the power.
CLOSED
4
OPEN
Initial Operation

– 8 –
Setting Hot Water Temperature
On this Display Operation Description
1
2Use the buttons
to adjust the
temperature.
Press the
ON/OFF button
to turn it “On”.
While the shower is being used, no one other than the user
should change the temperature, the power switch must not be
turned “off”.
WARNING
This is to prevent scalding if the temperature rises. Conversely, if the temperature drops or the power switch is
turned “off”, the user may be upset when the water suddenly becomes much colder.
* The
ON/OFF
is lit.
(Eg.: 40°C)
Here

– 9 –
•When a high temperature is set, the readout on the right is
shown.
•Please check the temperature displayed before using any hot
water.
Be especially careful using any hot water after any previous
setting of between 60 - 80°C.
Approximate hot water conditions
Washing
dishes, etc.
Shower, hot water supply, etc. Hot water supply, etc. High temperature
37 38 39 40 41 42 43 44 45 46 47 48 50 55 60 65 70 75 80
Set the maximum temperature to suit your own preference.
•Hot water temperatures are approximations, and may differ from actual temperatures depending on external
factors, such as the season and length of piping involved.
•When low temperatures are set (for washing dishes, etc.), if the ambient water temperature is already quite
high, it may be difficult to ensure the resultant water temperature is as per the setting.
•When the hot water temperature is adjusted using thermostat-controlled water mixing valves, set the temperature
on the remote controller to about 10°C higher than that required to ensure the appropriate temperature.
When setting high temperatures (60 - 80°C)
(Eg.: 60°C)
Temperature display
flashes for about 10
seconds to indicate
high temperature.
Here

– 10 –
Sequence
Water heating
Operation
NO
Safety device triggered
Flow is adjusted
than setting
outlet water temp. less
(1μA or more)
abnormality
Flame rod circuit
Water outlet thermistor
open or shorted
Water inlet thermistor
YES
Fan speed
> 2.5 L/min.
YES
NO
normal
Initial check
YES
Hot water demanded
Igniter stops sparking
detects > 1μA
Flame rod
Igniter sparks
ON/OFF lamp (green) lights
Main flow control valve opens
Connect power
ON/OFF button turn ON
Inlet water high
*1
Abnormal combustion
Fan speed
61
14
16 32
open or shorted
31
Water inlet thermistor
open or shorted
31
32
71
Fix problem
Fan motor stops
(Flame rod)
(Ignition failure)
11
12
61
72
Stop hot water demand
Turn power Off
ON/OFF lamp turns OFF
Disconnect power
Water flow sensor detects
(target 200 rpm)
(After 60 sec)
open or shorted
Flame Lamp
Water outlet thermistor
Error code stops flashing
90
YES
NO
14
Normal
NO
YES
10
99
Self-diagnosis
Combustion possible
(High-limit switch)
20
99
to more than 10 years
Using terms is equivalent
Main flow control valve
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
YES
The unit will continue to operature with
the code blinking.
Warning indication
Warning indication
(Fan abnormality)
1
4
5
9
11
12
14
15
16
17
8
1
6
5
610
10
5
6
8
temperature check
Igniter stops sparking
At max combustion, is
goes off
closes
Gas solenoid Valve 3
Gas solenoid valve 2
opens
Primary gas solenoid
valve opens
Gas proportioning valve
opens
Fan motor ON
Flame lamp
lights
Gas solenoid valve 3
opens or closes
Primary gas solenoid
valve closes
Gas solenoid valve 1
closes
Gas proportioning valve
closes
Flame lamp
goes off
closes
Gas solenoid valve 2
closes
Primary gas solenoid
valve closes
Gas solenoid valve 1
closes
(0.5μA or less)
not detect a flame
Flame rod does
is too high
Outlet water temp.
Abnormal gas solenoid
valve drive circuit
18
High limit switch
is normal
YES
NO (3rd)
Bypass flow control valve
and main flow control valve
move to initial position setting
device normal
Current leakage safety
NO
YES
of use
YES
5 years or more
NO
Maximum output limited
90
NO
YES
90
Self-diagnosis
Combustion possible
Self-diagnosis
Normal combustion
possible
Overheat prevention
device (Thermal fuse) normal
(Less than 184°C)
control valve operating
Main flow
YES
normal
NO
65
YES
Bypass flow
control valve operating
normal
NO
66
Setting 55°C or higher
YES
NO
Bypass flow control
valve closes
open or shorted
Heat exchanger thermistor
7
33
abnormality
Circuit board
70
NO
Extinction
(9 times or less)
YES
Ignition
Gas solenoid valve 1
13
Gas solenoid valve 2
closes
closes
Gas proportioning valve
Gas solenoid valve 3
opens
activates
33
Heat exchanger
open or shorted
7
thermistor
abnormality *3
(as necessary) *2
2
3
Overheat prevention
device (Thermal fuse)
triggered (184°C or more)
2
3
Warning indication
Warning indication
Warning indication
Drain trap Blockage
29
20
Drain trap Abnormality
(check for blockage and
electrode connections)
29
20
Total
A
p
K >
Set temp
e
K
If the inlet temp is less than 50
° C
or if the following statements
about K are true , the inlet temprature
will be normal (YES).
*1
kW/h
33.3
Out put Over
18.1
kW/h
Gas solenoid
valve 1
Gas solenoid
valve 2
Gas solenoid
valve 3
ON
ON
ON
ONON
Primary gas s
o
valve close
closes
closes
closes
Flame la
m
Gas proportioni
n
Gas solenoid
Gas solenoid
goes off
Gas solenoid
closes
Shutdown
p
Hot water tap C
Y
Fan motor pos
t
Main flow co
valve opens ful
Fan motor s
since hot water f
Has 6min. p
a
closed
Y
Heat
exchanger ther
< 40°C
Water flow sens
o
< 2.0 L/mi
valve close
s
Bypass flow c
*2 Over
*3 When the present fan speed is 500rpm more or less

– 11 –
Total water flow (L/min.)
Approx. 1.6 x 25
K >
+ water inlet temperature (°C)
Set temperature
K
If the inlet temp is less than 50
° C
58
° C Set temp + 10°C
Less than 53°C 53°C or more
or if the following statements
about K are true , the inlet temprature
will be normal (YES).
*1
kW/h
33.3
Out put Over
18.1
kW/h
ON
Over
11.7
kW/h
6.3
kW/h
Over
2.8
kW/h
Over
Gas solenoid
valve 1
Gas solenoid
valve 2
Gas solenoid
valve 3
ONON
ON
ON
ON ON
ONON
Primary gas solenoid
valve closes
closes
closes
closes
Flame lamp
Gas proportioning valve
Gas solenoid valve 2
Gas solenoid valve 3
goes off
Gas solenoid valve 1
closes
Shutdown procedure
Hot water tap CLOSED
YES
NO
Fan motor post purge
Main flow control
valve opens fully
Fan motor stops
since hot water fixture
Has 6min. passed
closed
YES
NO
Heat
exchanger thermistor
< 40°C
NO
Water flow sensor detects
< 2.0 L/min.
valve closes
Bypass flow control
*2 Over
*3 When the present fan speed is 500rpm more or less than target speed.

– 13 –– 12 –
Wiring Diagram and Inspection Flowchart
FR
DU
D
GND
<CN1>
BK BL
29
30
COLOR CODING
BK
W
IGNITER
W
WW
W
IG
FM
THERMAL FUSE
LS
SM
SM
LS
R
R
(VCC)
BR(Vs)
R(Vcc)
BL(GND)
Y(FG)
BL
BL
BL
BL
(Fully open)
(GND)
BL
YY
BL
BL
Y
R
BR
BL
Y
R
BR
BR RBLY
<CN27>
WW
(VCC)
BK
(VCC) V
G
O
W
(Fully open)
(VCC)
(GND)
R
O
Y
G
BL
G
O
V
BK
Y
O
R
1
2
1
2
1
2
1
2
3
4
1
2
3
4
5
6
7
8
1
2
2
1
1
1
3
1
2
3
4
1
2
1
2
1
2
1
2
3
1
2
3
3
2
1
3
2
1
4
5
6
7
8
G
BL
BK
VBK
V
<CN78>
BL
32 31
BL
W
W
W
W
W
W
WW
W
W
W
W
W
BK V
18 17
O
Y
Y
V
28
26
24
22
27
25
23
21
19
20
R
R
G
G
10
7
6
9
7
5
16
12
14
15
13
11
O
<CN38>
BL
R
4 3
12
<CN89>
BL
BL
IGNITER
<CN101>
DC15V
DC90V
THERMAL FUSE
GND
BK
W
CPU D
B
C
DC12V
C
SV3
SV2
SV0
SV1
IG
A
B
A
DC90V
3
2
4
6
5
BL
<CN104>
Y
W W O
G
<CN102>
<CN92>
BL W
<CN89A>
BLBL
BL
BL
R
<CN10>
W
G
BKW
GY
W
BK BL
BKO
O
GY
W
BL
BK
W
R
BK
<CN184>
G
BL
BL
1
R
R
BL
BK
G
BL
BL
W
3
10A(FUSE)
NEUTRAL
O
SV
OW
GY
BL
BK
W
W
0
10
BL
R
3
2
1
4
BL
-
+
R
DU
11
12
13
GY
GY
O
BK
BK
2
SV
SV
1
SV
3
1
2
4
Decrease Button
Set Button
Set Button
8
BL
6
<CN102>
W Y OR
15
32 4
W
3
<CN63>
WW
21
W
74 56
321 4
345 2 1
321
34 2 134 2 1
34 2 1
3 2 1
2 1 2 1 2 1 2 1
1 2 1 2 1 2 1 2
8
75 6
531
162 4
5
<CN75>
<CN70>
W
3
1
2
3
1
2
Y
R
4
3
1
2
11
Y
BL
10
9
8
6
5
4
3
1
2
6
7
5
4
3
1
2
8
6
7
9
13
15
14
12
<CN184>
6
5
184
3
W W
3
2
BK
R
1
2
BK
R
6
5
1
5
4
6
G
BL
BL
W(R)
BK(G)
R(W)
G(BK)
BL
BL
(W)R
(BK)G
(R)W
(G)BK
BL
BL
5
4
6
G
BL
BL
(GND)
(Vcc)
(Pulse)
R
Y
BL R
BL
Y
QS
BL
BL
DC140V
DC140V
W
BL
W
BL
BL
BL
W
BL
BL
BL
BL
FLAME DETECTING CIRCUIT
W
W
W
W
BR
BL
Y/G
BL BL
WW
TRANSFORMER
W
W
Y/G
BR
BL
BR
BL
GY
GY
BL
W WWW
WWW
W
WW W W
W
WW
W
Y/G
W WWW
WWW
W
WW W W
W
WW
W
BR
BR
R
R
R
W
WW
W
W
W
BK BK
BK
W
G
(GND)
V
V
WG
W
W
W
W
R
(GND)
R
R
WR
2
3
BL
W
W
W
G
R
(OPTIONAL)
(OPTIONAL)
B5
1
2
R
BK
RBK
V
R R
VARISTOR
ARRESTER
1
2
3
1
2
3
1
2
1
3
2
1
3
2
1
3
WATER LEVEL
ELECTRODE 2
WATER INLET
THERMISTOR
WATER OUTLET
THERMISTOR
HEAT EXCHANGER
THERMISTOR
BURNING LED
MAIN
FLOW
CONTROL
VALVE
BYPASS
FLOW
CONTROL
VALVE
WATER LEVEL
ELECTRODE 1
FLAME ROD
FAN MOTOR
REMOTE CONTROLLER
RC-7508M
RC TERMINAL
IGNITION
ELECTRODE
EARTH
HIGH-LIMIT SWITCH
(FOR PRIM A RY HEAT
EXCANGER)
HIGH-LIMIT SWITCH
(FOR FLUE BOX)
SYSTEM CONTROLLER
SC-201-6M INT
CURRENT
LEAKAGE
SAFETY DEVICE
(GFCI)
POWER CORD
<AC230V>
EARTH EARTH EARTH
FROST SENSING
SWITCH
ANTI-FROST HEATER
W : White
R : Red
BK : Black
V : Violet
O : Orange
BL : Blue
GY : Gray
G : Green
BR : Brown
Y : Yellow
EARTH
POWER
CIRCUIT
BOARD
MAIN
CIRCUIT
BOARD
WATER FLOW SENSOR
EXTERNAL POWER
CHANGE 3P CONNECTOR
(OPTIONAL)
CHANGE GAS CATEGORY
Other Unit in
Quick Connect
Multi System
MAIN CIRCUIT
BOARD
Manifold Pressure
Increase Button
Manifold Pressure
Minimum Manifold Pressure
Maximum Manifold Pressure
(For Quick Connect Multi System Only)
Quick Connect Cord(Optional)
GAS PROPORTIONING
VALVE
GAS
SOLENOID
VALVE
UNIT
HOT
VARISTOR
EARTH
FROST SENSING
SWITCH AN TI -F RO ST H EAT ER
AC230V
AC100V
CIRCULATION PUMP
RELAY 7
RELAY 10
RELAY 9
RELAY 3
RELAY 1
RELAY 4
RELAY 5
SOLENOID
VALVE 0
SOLENOID
VALVE 1
SOLENOID
VALVE 2
SOLENOID
VALVE 3
HIGH LIMIT
SWITCH
POWER
CONTROLLER
FAN
COMBUTION FAN
PRIMARY
SECONDARY
15V POWER CIRCUIT
WATER FLOW SENSOR
MAIN FLOW CONTROL VALVE
BYPASS FLOW CONTROL VALVE
WATER LEVEL
ELECTORODE 1
RELAY 1
RELAY 3
RELAY 5
RELAY 7
RELAY 10
RELAY
DRIVING
CIRCUIT
CENTRAL
PROCESSING
UNIT
GAS PROPORTIONING VALVE
POWER CONTROL CIRCUIT
FLAME ROD EARTH
FAN CONTROL
OUTPUT
FAN ROTATION
SPEED INPUT
FAN CURRENT
VALUE INPUT
FAN
PULSE
CONTROL
CIRCUIT
Sub-CPU
SUB C
ONTROL
UNIT
WATER OUTLET
THERMISTOR
WATER INLET
THERMISTOR
HEAT EXCHANGER
THERMISTOR
AIR INLET
THERMISTOR
WATER LEVEL
ELECTORODE 2
5V POWER CIRCUIT
PRIMARY
SECONDARY

– 14 –
Error Codes and Checkpoints
Description
Ignition Failure
(Initial Flame Fault
detection)
Flame Rod Does Not
Detect Flame (Secondary
Flame Fault Detection)
Overheat Cutoff Fuse
(Thermal Fuse) Triggered
Abnormally High Output
Temperature
High Limit Switch
Tr iggered
Water Inlet Thermistor
Abnormality
Water Outlet Thermistor
Abnormality
Heat Exchanger Thermistor
Abnormality
Multi-System CCP Valve
Abnormality
Fan Motor Abnormality
Main flow Control
Valve Abnormality
Bypass flow Control
Valve Abnormality
Gas Solenoid Valve Drive
Circuit Abnormality
Multi-System Controller
Board Error
Improper Circuit Board
Setting (Dip Switch etc.)
Remote Controller
Transmission Abnormality
Connection Error of Quick
Connect Cord
Combustion Abnormality
Combustion Abnormality
(Output Drop)
Combustion Abnormality
(Unit Shuts Off)
Flame Rod Circuit Abnormality
(Detection of Flame when
no flame is present)
Combustion Abnormality
(Joule Drop)
(Unit Continues Working)
Diagnosis Point (Trouble Point) Remarks
Display
(F) 10
(F)
11
(F)
12
(F)
14
(F)
16
(F)
20
(F)
31
(F)
32
(F)
33
(F)56
(F)
61
(F)
65
(F)
66
(F)
71
(F)
72
730
(F)
73
(F)
90
(F)
99
760
F
76
This error code is not mentioned in the flowchart.
This error code is not mentioned in the flowchart.
This model has two pieces of water level
electrodes. The front one is "No.2" and the
back one is "No.1".
Note 1)
Note 1)
Note 1)
Note 2)
During multi-system controller connection only.
To reset this error code, the power needs to
be disconnected and then reconnected.
To reset this error code, the power needs to be
disconnected and then reconnected.
To reset this error code, the power needs to
be disconnected and then reconnected.
To reset this error code, the power needs to be
disconnected and then reconnected.
This code is not mentioned in the flowchart.
This code is not mentioned in the flowchart.
This error code is not mentioned in the flowchart.
To reset this error code, the power needs to be
disconnected and then reconnected.
To reset this error code, the power needs to be
disconnected and then reconnected.
To reset this error code, the power needs to be
disconnected and then reconnected.
Check for abnormal combustion.
Check flue for blockage or obstruction.
Check for accidental extinction of the flame. Check for
abnormal combustion, check gas solenoid valves, check
flame rod. Check ground, especially on circuit board.
Check for melting or damage to the overheat cutoff fuse.
Check for improper connection of overheat cutoff fuse.
Measure the resistance through the water outlet thermistor.
Check for gas proportioning valve trouble.
Check gas manifold pressure.
Check if high limit switch is triggered.
Check for improper connection of high limit switch.
Measure the resistance through the water inlet thermistor.
Check for an open or short circuit.
Check for improper connection of the water inlet thermistor.
Drain trap Water Level
Electrode Abnormality
(F)29
Check for Drain trap blockage.
Check for drain pipe blockage.
Check for proper connection of drain trap water level electrode.
Measure the resistance through the heat exchanger
thermistor. Check for an open or short circuit. Check for
improper connection of the heat exchanger thermistor.
Check for an obstruction in the CCP valve.
Check for improper connection of multi-system wiring.
Check the inlet filter for an obstruction.
Check that the main flow control valve is functioning.
Check for the failure of the water flow sensor.
Heat exchanger flow
abnormality
(F)59
Check for scale build-up in heat exchanger.
Check for abnormal combustion.
Check flue for blockage or obstruction.
Check hat flame ignites all across the burner.
Check that the fan is rotating. Check for improper connection
of the fan. Check the pulse frequency from the fan rotational
frequency sensor. Check voltage from circuit board.
Check that the main flow control valve is functioning.
Check for improper connection of the valve.
Multi-System Controller
Communication Error
76
Check connection from remote controller to circuit board.
Check remote controller and circuit board for damage.
Check connection from multi-system controller to the unit.
SCU failure. Check for the circuit board of each unit.
Check that the bypass flow control valve is functioning.
Check for improper connection of the valve.
Check for damage to the gas solenoid valve drive circuit on
the circuit board.
Measure the current from the flame rod when there is no
flame. Check for a ground fault.
Malfunction of system controller electrical component board.
Circuit Board Abnormality
Number of the unit
decrease
(F) 70
Circuit board failure.
Check for proper setting of maintenance writers on circuit
board. Check circuit board for damage, check wiring
connections to circuit board.
Check connection from remote controller to circuit board.
Check remote controller and circuit board for damage.
Check for proper connection of quick connect cord.
Check for the circuit board of each unit.
Visually check flame. Check flue for blockage.
Visually check flame. Check flue for blockage.
Check that flame ignites all across the burner.
Check for abnormal combustion.
Check flue for blockage or obstruction.
Measure the resistance through the water outlet thermistor.
Check for an open or short circuit.
Check for improper connection of the water outlet thermistor.
Check gas supply piping and pressure. Check for igniter
spark. Check gas solenoid valves. Check flame rod.
Check ground, paying special attention to the ground
connection to the circuit board.
*In a Quick Connect (2-unit) Multi-System, "F##" (except F76) indicates an error code from the secondary unit (unit without a remote).
F76 refers to the connection error of quick connect cord.
Note 1) System controller connection only.
Note 2) The ON/OFF condition of both water level electrodes can be checked using the maintenance monitors.
When maintenance monitor number 19 reads "000", the conditions of both electrodes are normal. When this monitor reads "011",
the conditions of both electrodes are abnormal.
When this monitor reads "001", the condition of the only electrode "No. 1" is abnormal.
When this monitor reads "010", the condition of the only electrode "No. 2" is abnormal.
63
Circulation Pump
Abnormality
Check for a damage of Circulation Pump. Check for improper
connection of the circulation pump. Check for improper
Circulation pipe. Check for pump control unit.
Checkpoints and Measures if a Breakdown Occurs

– 15 –
Error Descriptions and How to Reset
Closed circuit (no open or short)
Connector No.
CN-89
1
Normal Value
Normal Value
Closed circuit
DC14 – 16V
DC14 – 16V
DC14 – 16V
Closed circuit
(not open or shorted)
2
6
1
BK/BL-R
BL-R
BL-BL
4
2
<After Pressing the Power On/Off Button on the Remote Controller>
1. If the Power On/Off lamp does not come on:
Error
Code
No
Error Code
10
760
90
99
Possible Causes Checkpoint
Error
Code Possible Causes Checkpoint
Check voltage supply from circuit board to
remote controller.
Check for open or short circuit.
Check remote controller and circuit board. Check
Remove the cause of excess current, then replace the 10A fuse.
If there is AC 100V supplied to the circuit board, but there is not DC 15V out of it,
the circuit board needs to be replaced.
Check for improper or damaged connections between the two boards, and for an
open circuit on the circuit board.
If voltage is abnormal, replace the circuit board.
If there is an open or short circuit, or a ground fault is detected, replace the cord.
Remote Control Terminal Block Voltage
Abnormality
Remote Controller Cord Abnormality
Connector No.
CN-102
CN-102
CN-89A
Pin No. &
Color Code
Pin No. &
Code Color
How to Fix Problem and Reset Unit
How to Fix Problem and Reset Unit
A blinking 10 indicates there has been a loss of gas input, but combustion will
continue. In order to reset the unit, the power must be disconnected and
then reconnected.
If there is a voltage abnormality, replace the circuit board.
1
If this error code is displayed and the water heater has been in use for 5 years,
the unit has reached the end of its life cycle and should be replaced.
Closed circuit (no open or short)
Connector No.
CN-89A
2
1
2.The Power On/Off lamp lights, but an error code appears soon after:
Normal Value
10
760
90
99
Error
Code Possible Causes Checkpoint
connection of remote control cord and cord to
circuit board.
..
Pin No. &
Code Color
.
Check maintenance monitor No.48. If the fan has increased its speed by 101
%
(3P : 104 %), the error code will flash but combustion continues. If the fan has
increased its speed by 102 %(3P : 105 %), the error code will flash and combustion stops.
If this error code is displayed and the water heater has been in use for 5 years,
the unit has reached the end of its life cycle and should be replaced.
If an open or short circuit or a ground fault exists, replace Remote Control cord.
If output fall is detected,the error code will flash and combustion stops.
This error code can be reset by turning the water heater OFF on the operation
panel. Remove the cause of the abnormal combustion.
2 or less
CN-38 31BL-BL25
14
Check for melting or improper connection of the overheat prevention device
(Thermal fuse).
Overheat Prevention Device
(Thermal Fuse)
If the overheat prevention device (Thermal fuse) has fused, it has been exposed to
temperatures in excess of 184°C. First fix the cause of the high temperature exposure
(hole in
heat exchanger, etc.) and then replace the overheat prevention device (Thermal fuse).
v v
v
Ω
A Fuse is Blown
Circuit Board Abnormality
Check whether the 10A fuse on the
circuit board is open.
Check the 15V ouput line from the
circuit board.
Check the 15V ouput line from the
circuit board.
DC13 – 16V1 BL-BL If voltage is abnormal, replace the circuit board.
CN-89 3
Circuit Board Abnormality Check the 15V ouput line from the
circuit board.
Connection line Abnormality
Combustion Abnormality
(Output fall)
Combustion Abnormality
(Warning Indication)
(Unit Shuts Off)
Combustion Abnormality
(Unit Shuts Off)
Check for abnormal combustion.
Check flue for blockage or obstruction.
Combusiton Abnormality
(Unit continues burning with error code
flashing and drop in heat output)
Remote Controller Transmission
Abnormality
DC14 – 16VBL-BL
Check for abnormal combustion.
Check flue for blockage or obstruction.
Check the cause of output fall.
Check for abnormal combustion.
Check flue for blockage or obstruction.
Check for abnormal combustion.
Check flue for blockage or obstruction.
Check remote control cord for a short or open
circuit, or for a ground fault.

– 16 –
10kHz – 100kHz
DC0.5µA or less
BL-Burner case
BL-Electrode
1
1
Normal Value
AC90V – 110V
DC80V – 100V
DC80V – 100V
DC0.3V – 15V
2
7
7
4
W-BK
W-BL
BK-BL
R-BL
5
6
5
2
2. Fan rotates normally, but no flame ignites on the burner:
Normal Value
10kHz – 100kHz
DC1
µ
A or more
See pg. 24
DC0.3 – 15V
GND
F-
rod
4
BL-Burner case
BL-Electrode
R-BL
1
1
2
3. A flame ignites on the burner, but it goes out immediately:
71
70
11
11
72
Error
Code Possible Causes Checkpoint
Error
Code Possible Causes Checkpoint
Measure the current from the flame rod
when there is no flame.
Check for a ground fault.
Igniter failure
Check the flame rod
Check the current from the flame rod
Check for a diconnected ground from the
circuit board
Check gas supply and manifold
pressures
Check gas proportioning valve
Check primary gas solenoid valve
Check gas solenoid valve 1
Check gas proportioning valve
Gas Solenoid Valve Drive Circuit
Abnormality
Ignition Failure
Flame Detecting Circuit abnormality
(initial flame fault detection)
Gas Supply Pressure or Manifold
Pressure Abnormality
Flame Rod Abnormality
(Flame detected when no flame present) CN-78
CN-10
CN-1(W), 10(BK)
CN-38
CN-38
Connector No.
CN-78
Connector No.
Pin No. &
Code Color
Pin No. &
Code Color
Replace Igniter
Gas Solenoid Valve typical resistance: 1075
Ω
to 1440
Ω.
Gas Solenoid Valve typical resistance: 1235
Ω
to 1660
Ω
.
How to Fix Problem and Reset Unit
Visually confirm that a flame ignites, check wiring connections to flame rod, and
check wiring connections to gas proportioning and gas solenoid valves.
Check f
or a bad contact or a bad connection between flame rod and
circuit board
,
check for a ground fault in the unit, especially the
circuit board
ground.
Check for damage or improper connection of the ground wire between the
circuit
board
and the metal case of the unit.
Current value changes depending on the load.
How to Fix Problem and Reset Unit
GND
F- rod
Detection of
circuit board
abnormality.
Circuit board
Abnormality
Disconnect the electrical power, then reconnect electrical power to the water heater to
reset the system. If the
circuit board
abnormality is continuous, replace the
circuit
board
.
Disconnect the electrical power, then reconnect electrical power to the water heater to
reset the system. If the error code "71" is continuous, replace the
circuit board
.
If the "72" error code is displayed, check the signal from the flame rod (also make sure
that there is not a problem with the grounding of the appliance).
If the signal is normal, replace the
circuit board
. If it is abnormal, replace the flame rod.
Current value changes depending on the load.
Normal Value
2.5 L/min.
1 or less
Connector No.
CN-63
CN-1
CN-63
CN-63
CN-63
2
6
2
2
2
W-W
BK-W
W-W
W-W
W-W
4
3
4
1
3
<During Regular Operation>
1. Fan does not begin rotating when hot water is being demanded:
No
Error
20
29
31
32
33
Error
Code Possible Causes Checkpoint
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Pin No. &
Code Color How to Fix Problem and Reset Unit
to be replaced.
Compare to temperature characteristic list on pgs. 16.
If no.19 is [001] : Only Electrode No.1 is ON, [010] : Only Electrode No.2 is ON,
[011] : Both Electrodes are ON, check the following :
Check for Drain Trap blockage. Check for drain pipe blockage.
Check for proper connection of Drain Trap water level electrode.
Check for short circuit of Drain Trap water level electrode cord.
If normal value, replace the circuit board.
Both Electrodes
OFF [000]
Compare to temperature characteristic list on pgs. 16.
Check for open or short circuit or for an improper connection.
Check for open or short circuit or for an improper connection.
Check for open or short circuit or for an improper connection.
Compare to temperature characteristic list on pgs. 16.
Normal Value.
W
Check maintenance monitor no. 14
Check inlet water temperature
Check if high limit switch is triggered or
improperly connected.
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Check the resistance through the thermistor.
Check for open or short circuit,or improper connection.
Water Flow Sensor Abnormality
Inlet Water Temperature is too High
Water Inlet Thermistor Abnormality
Drain Trap Water Level Electrode
abnormality
Check maintenance monitor no. 19
Water Outlet Thermistor Abnormality
Heat Exchanger Thermistor Abnormality
High Limit Switch Triggered
.How to Fix Problem and Reset Unit
If the flow monitor indicates higher than the minimum, the circuit board will need
Make Sure there is no flame left over in the burner. Check for short or open
circuit. Reset unit by turning power off and on. Replace high limit if code remains.
.
.
OK if K > 1.6 x 25/Flow Rate (L/min.) + inlet water temp (°C), where K = 58°C for 53°C
or lower temperature setting, K= Set Temp (
°
C) + 10°C for 53°C or more setting.
Also check thermistor temperature characteristics.
Ω
Check for damage to the gas solenoid valve
drive circuit on the
circuit board
.
Proportioning valve resistance: 55
Ω
– 75
Ω
.
Proportioning valve resistance: 55
Ω
– 75
Ω
.

– 17 –
Normal Value
DC7V – 48V
DC10V – 14V
150Hz – 400Hz
(4 pulse/rev.)
2
2
2
BR-BL
R-BL
Y-BL
4
1
3
5. Fan does not begin rotating, or the fan rotation is abnormal when hot water is being demanded:
Normal Value
See pg. 24
DC1 – 16V
DC1 – 16V
DC1 – 16V
DC1 – 16V
DC1V or less
DC1 – 16V
DC1 – 16V
DC1 – 16V
DC1 – 16V
DC1V or less
DC1 – 4.5V
DC0.3 – 15V
26
27
28
30
29
15
16
17
18
29
2
4
BL-O
BL-G
BL-V
BL-BK
Y-BL
BL-O
BL-G
BL-V
BL-BK
Y-BL
W-W
R-BL
25
25
25
25
24
25
25
25
25
20
1
2
6. Temperature control problem:
61
65
66
16
Check that the fan is rotating and check
the pulse frequency from the fan rotational
frequency sensor.
Check for improper connection of the fan.
Check voltage from
circuit board
.
Check gas supply and manifold
pressures.
Check main flow control valve.
is functioning. Check for improper
connection of the valve.
Check gas proportioning valve.
Check the resistance of the water outlet
thermistor.
Fan Motor abnormality
Gas supply pressure or manifold
pressure abnormality
Main Flow Control Valve Abnormality
Bypass Flow Control Valve Abnormality
Abnormally High Output
(temperature is too hot)
Connector No.
CN-27
Connector No.
CN-38
CN-38
CN-63
CN-38
Pin No. &
Code Color
Pin No. &
Code Color
During Operation.
During Operation.
During Operation.
During Operation.
When valve is fully open.
If the heat exchanger thermistor temp. is 92
°
C and over for 0.3 second with the all
set temp.
If the outlet thermistor temp. is 90
°
C and over for 0.3 second with the all set temp..
If the outlet thermistor temp. is (set temp. + 10
°
C) and over for 25 seconds with the
set temp. more than 50
°
C.
If the outlet thermistor temp. is 60
°
C and over for 25 seconds with the set temp.
50
°
C and less. The unit will shut off and a 16 error code will flash.
When valve is fully open.
Check for short or open circuit or improper connection of wiring to valve.
During Operation.
During Operation.
During Operation.
During Operation.
No
Indication
Error
Code Possible Causes Checkpoint
Error
Code Possible Causes Checkpoint How to Fix Problem and Reset Unit
How to Fix Problem and Reset Unit
Confirm the measured fan speed by Maintenance Monitor (No.10).
If the fan motor does not rotate, but voltage is normal, then the fan motor should
be replaced. If the voltage is abnormal, replace the
circuit board
.
If the fan motor is rotating and if the voltage is normal, but there is a "61" error
code, then the fan motor should be replaced.
Check for improper connection of the valve.
Check that the bypass flow control valve
Normal Value
10kHz – 100kHz
DC1
µ
A or more
See pg. 24
DC0.3 – 15V
GND
F-
rod
4
BL-Burner case
BL-Electrode
R-BL
1
1
2
4. Flame goes out while hot water is being supplied:
12
Error
Code Possible Causes Checkpoint
Check the flame rod
Check the current from the flame rod
Check for a diconnected ground from the
circuit board
Check gas supply and manifold
pressures
Check gas proportioning valve
Flame Rod Triggered
(Doesn't sense flame during operation)
Gas Supply Pressure or Manifold
Pressure Abnormality
CN-78
CN-38
Connector No. Pin No. &
Code Color
Visually confirm that a flame ignites, check wiring connections to the flame rod,
and check wiring connections to gas propor tioning and gas solenoid valves.
Check for a bad contact or a bad connection between the flame rod and
circuit board
.
Check for a ground fault in the unit, especially the
circuit board
ground.
Check that the input is proper for the load.
Current value changes depending on the load.
Proportioning valve resistance: 55
Ω
- 75
Ω
.
How to Fix Problem and Reset Unit
Check for damage or improper connection of the ground wire between the
circuit
board
and the metal case of the unit.
<During Regular Operation>
Water Inlet / Water Outlet / Heat Exchanger Thermistor Temperature Characteristics
Ω)
Temperature (˚C)
Resistance (k 7.010.315.523.7
0 2010 30
1.41.9
2.53.54.9
5040 60 70 80

– 18 –
Main Remote Control
(RC-7508M)
Displaying the Maintenance Monitor
Display
Set Button
Speaker
Power On/Off Button / Lamp
Selection Button
The Power On/Off Button can be set to either "ON" or "OFF" - unit operation will not be affected by this setting.
However, be sure to set the
Power On/Off Button to “ON” after turning on the power.
<Display procedure>
1. Press and hold both the up [ ] and down [ ] selection buttons simultaneously for more than five seconds.
2. “Maintenance Monitor” display will appear along with the data no. and data.
3. Displaying data and switching data no.
(1) Press the up [ ] selection button to switch display to the next item no. Press the down [ ] set button to
switch display to the previous data no.
(2) Press the selection button to change to the ten's digit. Use the selection buttons [ ] and [ ] in the same
manner as (1) to make changes.
* If more than one Quick connect Multi System is installed, the mode shifts to the mode for switching the
device No. by pressing the selection buttons.
If the device No. is switched by pressing selection buttons [ ] and [ ], the data of each device is displayed.
device No. data
00 Master (device to which the remote controller is connected)
01 Slave (device to which the remote controller is not connected)
The temperature of hot water etc. cannot be changed while Maintenance Monitors are displayed.
<Returning to Normal Mode>
1. To return to normal mode, press and hold both up [ ] and down [ ] of selection buttons simultaneously
more than two seconds. The unit will also return to normal mode if no buttons are pressed for 10 minutes.
<Displaying the Error code history>
1. After switching to the maintenance monitor mode, press the [ ] selection button to switch to error code
history 1.
2. Up to eight error histories are stored in memory from error code history 1 (most recent) to error code history
8.
3. If there is no error history, "000" will appear in the data.
4. To clear the error code history from memory, exit maintenance monitor mode, push the
Power On/Off Button
to "OFF", and press and hold the [ ] select button for more than 5 seconds (tone will sound). Error code
history will not be cleared by turning off the power.

– 19 –
Maintenance Monitor List
10 times
1 hour
X 1
14
15
18
20
*2
*1
Heat Exchanger Flow Rate X 0.1
L/min. 0.1 L/min.
0.1 L/min.
L/min. X 0.1
Number of Ignition Times
Total Combustion Time
10 rpm
rpm
% 1 %
1 %
X 10
X 10
25 rpm
25 rpm
Disp. Range [000] – [999] 07 time
Item
Data
(Display Reading x Multiplier)
Multiplier Unit
Minimum
Value for
Indication Remarks
Disp. Range [000] – [999]
Disp. Range [000] – [1300]
03 Total Plug-in Time
04
Data
No.
hour
1000 hours
X 1000
Total Combustion Time
Disp. Range [000] – [1999] 05 hour
hourX 100 100 hours
Under judgement [000]
2L[1100],2H[1300]
2L(Dip switch)[1109],
2H(Dip switch)[1309]
• Both electrodes : OFF [000]
• Electrode No.1 only : ON [001]
• Electrode No.2 only : ON [010]
• Both electrodes : ON [011]
02 2E
+
gas judgement result [ab : cd]
X 10
10000 timesNumber of Ignition Times
Disp. Range [000] – [1999] 08 timeX 10000
°CX 0.130
31 X 0.1 °C
0.5°C
0.5°C
0.5°C°CX 0.132
Water Inlet Thermistor
Temperature Reading
Water Outlet Thermistor
Temperature Reading
Heat Exchanger Thermistor
Temperature Reading
X 1
Simple Self-diagnosis Counter
FF No.
FF+FB No.
Output
Circuit Board ID1: Product 1
Circuit Board ID2: Product 2
Circuit Board ID3:Version
Position of Main Flow
Control valve
Position of Bypass Flow
Control Valve
62 X 2 step
[000] – [036]
Total Flow Rate
Fan Rotational Frequency
Output (%)
19 [x : xx]
Drain Trap Water Level Electrode
Calculated Fan Speed
47 [0 : xx]
A=101,B=102,C=103,...Z=126
A=201,B=202,C=203,...Z=226
A=301,B=302,C=303,...Z=326
87 [1 : xy]
88 [2 : xy]
89 [3 : xy]
Decimal
Final Fan Speed Correction
2H/2E [000] – [105], 3P[000] – [102] 49 X 1 %
50 X 0.1 0.1
0.1
0.1
[000] (Open) – [1350](Closed) step
51 X 0.1
52 X 0.1
60 step X 2
*1 A difference in the calculated (#20) and the measured (#10) fan speeds of ±500 or less is normal.
*2 To view the maintenance monitors of another unit in a multi-system installation, press the SET button
(while in monitor mode) to switch to the desired unit.
Position of Main Flow
Control valve limiter
Open [000], Unlimited [AAA],
Fully closed [315], Error [EEE]
[000] (Open) – [1350](Closed) step
Open [000], Unlimited [AAA],
Fully closed [315], Error [EEE]
61
Position of Bypass Flow
Control Valve limiter
63
95
97
98
91
92
93
94
96
X 1
Proportioning valve output capacity
90
Most Recent Error
Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Next Most Recent
Error Code
Error Code History 8
Error Code History 7
Error Code History 6
Error Code History 5
Error Code History 4
Error Code History 3
Error Code History 1
Error Code History 2 If the same error code is
repeated, it will appear in
the history list twice.
If it is repeated more than
twice, it will only appear
twice.
[000] – [1000]
1 %
Initial Fan Speed Correction
2H/2E [000] – [105], 3P[000] – [102] 48 X 1 %
+
+

– 20 –
Circuit Board Replacement
[ RC-7508M ]
It is necessary to transfer data when replacing a circuit board. Vital
information about the water heater such as the settings and unit history
will have to be transferred to the new board. Please transfer data using
the following procedure. If the transfer is not successful, the unit will
not operate and a 73 error code will flash on the remote controller.
* Be sure to read.
Data Transfer Procedure
Initial Circuit Board Settings
Connecter CN89
89
89
Model
0
0
06
Select Button
07
Main Controller
SET
ON/OFF
onestens
hundreds hundreds
tens ones
0
0
Circuit Board Resetting
Model No. Changing Procedure
0
0
0
0
Model
hundreds
08
tens
hundreds
0
ones
4
tens
09
179
ones
0
0
0
0
0
0
0
21 1
1
3
7
3
30 0
9
1
7
5
7
2
25 57
9
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
03
3
3
3
3
3
3
3
0
0
0
0
0
0
0
04
4
4
4
4
4
4
0
00 0
00
00
0
0
0
00 0
0
00 00
0
3
3
3
3
00
0
00 0
00 000
0
00 00
0
000
3
3
3
3
00 00
00
00
4
4
4
4
0
00 0
00
00
4
4
4
4
1
1
1
1
3
3
2
2
78
30
06
58
I
I
I
I
3P
2H
2L
2E
I
2E
2L
I
I
2H
I
3P
2E
I
I
2L
I
2H
I
3P
I
2E
I
2L
I
2H
I
3P
3P
I
I
2H
I
2L
I
2E
I
2E
I
2L
I
2H
I
3P
I
2E
I
2L
I
2H
I
3P
I
2E
I
2L
I
2H
I
3P
80
32
08
60
4
41 16
60
00 01 1
14060 1
I
I
2E
I
2H
0
01 17 80
73
36 6
036180
I
3P
I
2E
2H
I
WH56
WH42
WHX42
WHX56
WH56
WHX56
WH42
WHX42
3P
When a circuit board is replaced, data must be transferred from the old board, otherwise a " 73 " error code
will flash on the remote controller and the unit will not operate.
After installing the new circuit board, please transfer data according to the following procedure:
1. With the power turned off, remove the remote controller connection from
connection number CN89. Also, if connected, undo system controller connections
before transferring data. In case of quick Connect Multi System (connecting system without a system controller),
keep the quick connect cord connecting.
2. Using the supplied transfer cable, connect the new and old boards by
inserting the cable in connection number CN89 of each board.
3. Turn the power on. The data transfer will be completed in about 30 seconds.
The unit will signal a successful transfer by rotating the fan and opening and
closing the gas solenoid valve.
4. After confirming a successful transfer, turn the power off. Remove the
cable connecting the new and old circuit boards. Reconnect system controller
and remote controller connections.
Data Transfer Troubleshooting
1. If this is the first time that the circuit board has been replaced:
Please follow the procedure "Initial Circuit Board Settings".
2. If this is the second time that the circuit board has been replaced:
Please follow the procedure "Circuit Board Resetting".
*If data has already been transferred to the board, follow the resetting procedure.
**Once data has been transferred to a new board, the transfer procedure cannot
be performed again.
*In the case of multi-installation(multi-system installation with system
controller), disconnect system controller and connect remote controller.
*In the case of the quick connect multi-system installations(multi-system
installation without system controller) leave quick connect cord connected
and connect remote controller.
*After replacing the circuit board, make sure all connections are made
to the board before making the initial circuit board settings.
1. In order to switch to maintenance writer, press and hold the or button with operation
switch off, within 10 minutes after power on. (The display blinks "99")
If it doesn't change the mode, remove the power plug and do the same operation as above.
2. By pressing , the address will advance one by one.
(10 11 19 1A 1B 3F FC FD FE FF 10 11 )
By pressing , the address will revert one by one.
(10 FF FE FD FC 3F 3E 1A 19 18 10 FF )
3. 'The data display' will blink by pressing 'set' button while item number displayed is blinking.
Then switch on/off by pressing the sellect button for 1 second.
4. Change "FE" and "FC" from OFF to ON in order to access the hidden maintenance writers.
(display blinks with "A0".)
5. Press to move the next item.
(A0 A1 AF B0 B1 BF 06 07 08 09 A0 A1 )
Press to move the former item.
(A0 09 08 07 06 BF BE B0 AF AE A0 09 )
6. Scroll to "06" the model number will be displayed in three digits in the data display.
7. Under a condition of displaying "Item No. 06", adjust the 3 digits model number to be set following
the procedure under "Model No. Changing Procedure" . (Refer model number to the model number
tables right.)
8. Set the model number following the same procedure as 5-7 for "Item No.07", "08", and "09" as well.
9. When all of the maintenance writers have been set correctly, press the 'Set' button.
(The display blinks the item number. )
And confirm the settings by pressing and holding both and buttons on the remote
controller until the controller emits a beeping noise. The new settings will be lost if this is not done.
Note 1. To cancel the settings, let the controller sit for 10 minutes,
or turn on the operation button. The information set previously
will be canceled. To change settings again, follow steps 1 through 9.
Note 2. Only change data as listed in the "Setting list" table.
Reference connection diagram
(for simplification, other connections have been omited)
Disconnect when
transferring
Buttons for adjusting the manifold
pressure settings
To Remote Controller
Terminal Block
New
Circuit
Board
Old
Circuit
Board
Electric wire attached with a New
Circuit Board for Servicing
1. Install the circuit board into the unit and make all wiring connections.
2. Within the first ten minutes of connecting power to the unit, perform
steps 1 through 4 of the "Initial Circuit Board Settings" procedure.
This should result in "A0" blinking on the remote controller.
3. If the "A0" maintenance writer is "ON" , press the 'set' button to blink the data
display. And press the sellect button for 1 second to change "A0" to "OFF".
4. Press the setting button to blinks the display's item number. And press and hold
both the and buttons on the remote controller until the
controller emits a beeping noise. The new settings will be lost if this is not done.
5. The operation above enables the data transfer for this board anew.
Next, follow "method of data transfer between boards".
1. Hundred's place : When the display blinks with "06" , press the 'Set' button.
(Then the hundred's place blinks.)
Under a condition of the hundred's place blinking, adjust the number
by pressing or .
2. Ten's place : Change the blinking place from the hundreds to tens by pressing the
'Set' button. And adjust the tens following the same procedure as
the hundreds adjustment.
3. One's place : Change the blinking place from the tens to ones following the same
procedure. And adjust the ones.
4. When the one's place is blinking, press the 'Set' button. Then the display blinks " 06" ,
and you can change the item number from "06" to "07", "08", and "09".
Setting list (check the attached manual for model and gas type)
Category
Model No. Setting Data
LWH56
LWHX56
LWH42
LWHX42
LWHC56
WHC56
Model No. Setting Data
Category
LWH56
LWHX56
LWH42
LWHX42
LWHC56
WHC56
*Always turn the power off prior to connecting/disconnecting the connectors.
Othewise, damage may occur to the circuit board as a result.
**After replacing the board, check and adjust manifold gas pressure settings to
the values listed on the service manual.
***When you cannot transfer data between the boards, please follow the procedures
under "Data Transfer Troubleshooting".
Display
(Data No. and Data)
'Set' Button
(Data No. change)
Operation Button
(Display change)
(Data No. change)
(Swiching ON/OFF)
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