Mitsubishi Electric Mr.Slim MSZ-GC22NA - C1 User manual

SERVICE MANUAL
CONTENTS
1. PART NAMES AND FUNCTIONS····················· 3
2. SPECIFICATION················································ 4
3. OUTLINES AND DIMENSIONS ························ 5
4. WIRING DIAGRAM············································ 7
5. REFRIGERANT SYSTEM DIAGRAM ··············· 9
6. SERVICE FUNCTIONS ··································· 10
7. MICROPROCESSOR CONTROL ··················· 12
8. TROUBLESHOOTING····································· 18
9. DISASSEMBLY INSTRUCTIONS···················· 39
Models
MSZ-GC22NA - C1
MSZ-GC25NA - C1
MSZ-GC35NA - C1
MSZ-GC35NA - C2
MSZ-GC50NA - C1
MSZ-GC60NA - C1
MSZ-GC71NA - C1
SPLIT-TYPE AIR CONDITIONERS
MSZ-GC22/25/35NA
INDOOR UNIT
Outdoor unit service manual
MUZ-GC·NA Series(OBH482)
MXZ-A·NA Series (OB430)
PARTS CATALOG (OBB481)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
No. OBH481
REVISED EDITION-A
Please void OBH481.
Revision A:
• MSZ-GC35NA - C2 has been added.

2
Revision A:
• MSZ-GC35NA - C2 has been added.
MSZ-GC35NA - C1 →MSZ-GC35NA - C2
• FAN MOTOR has been changed. (AC →DC)

3
Remote control
receiving section
Emergency operation switch
Emergency operation switch
Operation indicator lamp
Remote control
receiving section
Operation Indicator
lamp
Operation Indicator
lamp
Remote control
receiving section
Emergency operation switch (E.O. SW)
Air outlet
Vertical vane
Air inlet
Front panel
Catechin air filter
Horizontal vane
Remote controller
Line flow fan
Air cleaning filter
(Anti-allergy enzyme filter, option)
MSZ-GC22NA
MSZ-GC25NA
MSZ-GC35NA
MSZ-GC60NA
MSZ-GC71NA
MSZ-GC50NA
MSZ-GC22NA
MSZ-GC25NA
MSZ-GC35NA
MSZ-GC60NA
MSZ-GC71NA
MSZ-GC50NA
ACCESSORIES
MSZ-GC22/25/35/50 MSZ-GC60/71
Installation plate 1 1
Installation plate fixing screw 4 × 25 mm 5 7
Remote controller holder 1 1
Fixing screw for 3.5 × 1.6 mm (Black) 2 2
Battery (AAA) for remote controller 2 2
Wireless remote controller 1 1
Felt tape (Used for left or left-rear piping) 1 1
1PART NAMES AND FUNCTIONS

4
Indoor model MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA
Function Cooling Heating Cooling Heating Cooling Heating
Power supply Single phase 220 - 230 V, 60 Hz
Electrical
data
Running current 1 A 0.24
Power input 1 W 45
Fan motor
Model RC4V18-BA
C1 RC4V18-BA
C2 RC0J40-EF
Current 1 A 0.24 C1 0.24
C2 0.27
Dimensions W × H × D mm 788 × 295 × 234
Weight kg 9
Special remarks
Air flow (Super High) m3/h 576 600 576 600 534 570
Air flow (High/Med./Low) 462/354/246 480/378/276 462/354/246 480/378/276 444/330/234 462/354/246
Air direction 4
Sound level (Super High)
dB(A)
43
Sound level (High/Med./
Low) 36/29/21 36/29/22
Fan speed (Super High) rpm 1,070 1,100 1,070 1,100 1,080 1,140
Fan speed (High/Med./
Low) rpm 890/720/550 920/760/600 890/720/550 920/760/600 930/740/580 960/780/600
Fan speed regulator 4
Remote controller model KM05B
Indoor model MSZ-GC50NA MSZ-GC60NA MSZ-GC71NA
Function Cooling Heating Cooling Heating Cooling Heating
Power supply Single phase 220 - 230 V, 60 Hz
Electrical
data
Running current 1 A 0.35 0.6
Power input 1 W 40 60
Fan motor Model RC0J30-CC RC0J56-AA
Current 1 A 0.35 0.6
Dimensions W × H × D mm 780 × 298 × 210 1,100 × 325 × 258
Weight kg 9 16
Special remarks
Air flow (Super High) m3/h 654 –
Air flow (High/Med./Low) 594/445/414 1,032/768/522 1,032/786/522 1,032/798/564 1,032/816/564
Air direction 4 5
Sound level (Super High)
dB(A)
48 –
Sound level (High/Med./
Low) 44/38/32 54/40/32 54/40/33
Fan speed (Super High)
rpm
1300 –
Fan speed (High/Med./
Low) 1,200/1,100/900
1,310/1,030/750 1,310/1,050/750 1,310/1,080/800 1,310/1,080/800
Fan speed regulator 4 3
Remote controller model KM05B KM05C
NOTE : Test conditions are based on CNS 14464, ISO 5151.
Cooling : Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C
Heating : Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
1 Measured under rated operating frequency.
2SPECIFICATION

5
Unit : mm
7459
41.5
214
235
253.5 18.5
320335
155 155
21540.5 254.5
5959 225 225
2
295
53 607 128
8
100
137
119
Piping
Insulation ø35 O.D
Liquid line ø6.35 - 0.5 m (Flared connection ø6.35)
Gas line ø9.52 - 0.43 m (Flared connection ø9.52)
Drain hose Insulation ø28 O.D Connected part ø16 O.D
11 ×26 Oblong hole 11 ×20 Oblong hole
Installation plate
Indoor unit Wall hole ø65
Air in
Air out
Installation plate
Piping
Drain hose
234 5
788
19
159
58
MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA
Specifications and rating conditions of main electric parts
Model
Item MSZ-GC22/25/35 MSZ-GC50 MSZ-GC60/71
Fuse (F11) T3.15AL 250 V
Horizontal vane
motor (MV) 12 VDC MSBPC20M16 12 VDC 250 Ω(at 25˚C) —
Vane motor (MV1/MV2) — — MP20/MP20
Varistor (NR11) S10K320E3K1 (ERZV14D471) ERZV14D471
Terminal block (TB) 3 P 4 P
3OUTLINES AND DIMENSIONS

6
258
47
7.5
315
255.547
2.5
98 173
98 173414.5 414.5
5
253
791
56
1068
1100
325
Air out
Air in
Insulation ø28
Drain hose ø16
(Connected part O.D)
Installation plate
Wall hole ø75
Installation plate Indoor unit
{
Liquid line ø6.35-0.5 m
Gas line ø12-0.43 m
Insulation ø50 O.D
ø32 I.D
{
Liquid line ø9.52-0.5 m
Gas line ø12-0.43 m
Insulation ø50 O.D
ø32 I.D
for MSZ-GC60
for MSZ-GC71
19
159
58
MSZ-GC60NA MSZ-GC71NA Unit : mm
Unit : mm
155 155
335 320
41.5 215
42.5 214
3287.5
7055
5555 225 225
or more7
100
90
106
298
102624.5
780
210 5
53.5
19
159
58
14273.5
234
Air in
Air out
Wall hole ø65
Indoor unit
Installation plate
Installation plate
11×20 Oblong hole
11×26 Oblong hole
Insulation ø28
Drain hose ø16
(Connected part O.D)
Liquid line ø6.35-0.5 m
Gas line ø9.52-0.43 m
Insulation ø35 O.D
ø19 I.D
{
MSZ-GC50NA

7
MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA - C1
MSZ-GC35NA - C2
4WIRING DIAGRAM

8
MSZ-GC50NA
MSZ-GC60NA MSZ-GC71NA

9
MSZ-GC22NA MSZ-GC25NA
MSZ-GC35NA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13(sub)
Flared connection
Refrigerant pipe ø9.52
(with heat insulator)
Refrigerant pipe ø6.35
(with heat insulator)
Indoor coil
thermistor
RT12(main)
MSZ-GC71NA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13(sub)
Flared connection
Refrigerant pipe ø15.88
(with heat insulator)
Refrigerant pipe ø9.52
(with heat insulator)
Strainer
#50
Indoor coil
thermistor
RT12(main)
Refrigerant flow in cooling
Refrigerant flow in heating
MSZ-GC50NA
MSZ-GC60NA
Unit:mm
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe ø12.7
(with heat insulator)
Flared connection
Flared connection
Indoor coil
thermistor
RT12(main)
Refrigerant pipe ø6.35
(with heat insulator)
Distributor
Indoor coil
thermistor
RT13(sub)
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe ø15.88
(with heat insulator)
Flared connection
Flared connection
Indoor coil
thermistor
RT12(main)
Refrigerant pipe ø6.35
(with heat insulator)
Distributor
Indoor coil
thermistor
RT13(sub)
5REFRIGERANT SYSTEM DIAGRAM

10
6-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS on the indoor electronic control P.C. board.
The time will be shortened as follows. (Refer to 8-7.)
Set time : 1-minute →1-second
Set time : 3-minute →3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by short circuit-of JPG and JPS.)
6-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must be
modified according to the number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
NOTE : For modification, take out
the batteries and press
the OPERATE/STOP (ON/
OFF) button twice or 3
times at first.
After finish modification,
put back the batteries then
press the RESET button.
J2
J1
How to set the remote controller exclusively for particular indoor unit
After you turn the breaker ON, the first remote controller that sends the signal to the indoor unit will be regarded as the remote
controller for the indoor unit.
The indoor unit only accept the signal from the remote controller that has been assigned to the indoor unit once they are set.
The setting will be cancelled if the breaker has turned OFF, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.
The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
Table 1
1 unit operation 2 units operation 3 units operation 4 units operation
No. 1 unit No modification Same as at left Same as at left Same as at left
No. 2 unit – Solder J1 Same as at left Same as at left
No. 3 unit – – Solder J2 Same as at left
No. 4 unit – – – Solder both J1 and J2
MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA MSZ-GC50NA MSZ-GC60NA MSZ-GC71NA
6SERVICE FUNCTIONS

11
NOTE:
• The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the
remote controller.
• If main power is turned OFF or a power failure occurs while AUTO START/STOP timer is active, the timer setting is
cancelled.
• If the unit has been OFF with the remote controller before power failure, the auto restart function does not work as
the power button of the remote controller is OFF.
• To prevent breaker OFF due to the rush of starting current, systematize other home appliance not to turn ON at the
same time.
• When some air conditioners are connected to the same supply system, if they are operated before power failure, the
starting current of all the compressors may flow simultaneously at restart.
Therefore, the special counter-measures are required to prevent the main voltage-drop or the rush of the starting
current by adding to the system that allows the units to start one by one.
JR07
CN151 CN211CN112 CN1R1
BZ
6-3. AUTO RESTART FUNCTION
When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan speed
are memorized by the indoor electronic control P.C. board. The “AUTO RESTART FUNCTION” sets to work the moment
power has restored after power failure. Then, the unit will restart automatically.
Operation
If the main power has been cut, the operation settings remain.
After the power is restored, the unit restarts automatically according to the memory.
(However, it takes at least 3 minutes for the compressor to start running.)
How to release “AUTO RESTART FUNCTION”
Turn OFF the main power of the unit.
Solder the Jumper wire JR07 on the indoor electronic control P.C. board. (Refer to 8-7.)
JR07
CN151
CN152
CN101
CN211CN112
BZ
MSZ-GC60/71MSZ-GC50
JR07
CN10A CN111
CN151 CN112
MSZ-GC22/25/35

12
NOTE: Last setting will be stored after the unit is turned OFF with the remote controller.
Indoor unit receives the signal of the remote controller with beeps.
WIRELESS REMOTE CONTROLLER
Operation Indicator lamp
The operation indicator at the right side of the indoor unit indicates the operation state.
•The following indication applies regardless of shape of the indicator.
INDOOR UNIT DISPLAY SECTION
MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA MSZ-GC50NA MSZ-GC60NA MSZ-GC71NA
ON/OFF
TOO
COOL
TOO
WARM
LONG
Open the front lid.
Signal transmitting section
Operation display section
OPERATE /STOP
(ON /OFF)button
TEMPERATURE buttons
Indication of remote controller
model is on back.
ON TIMER button
CLOCK SET button
TIME SET buttons
FORWARD button
BACKWARD button
VANE CONTROL button
(Horizontal vane button)
OFF TIMER button
LONG button
(MSZ-GC60/71)
RESET button WIDE VANE button
(Vertical vane button)
(MSZ-GC60/71)
FAN SPEED CONTROL button
OPERATION SELECT button
ECONO COOL button
These pictures show MSZ-GC60/71
Indication Operation state Room temperature
or The unit is operating to
reach the set temperature
About 2°C or more away
from set temperature
or
The room temperature is
approaching the set tem-
perature
About 1 to 2°C from set
temperature
or
Standby mode
(Only during multi system
operation)
-
Lighted
Blinking
Not lighted
MICROPROCESSOR CONTROL
7

13
7-1. COOL ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns ON.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Coil frost prevention
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the coil
from frosting.
When the temperature of indoor heat exchanger becomes too low, the coil frost prevention mode works.
The indoor fan operates at the set speed and the compressor stops. This mode continues until the temperature of indoor
heat exchanger rises.
7-2. DRY ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns ON.
(2) Select DRY mode with OPERATION SELECT button.
(3) The set temperature is determined from the initial room temperature.
1. Coil frost prevention
Coil frost prevention is as same as COOL mode. (7-1.1.)
7-3. HEAT ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns ON.
(2) Select HEAT mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Cold air prevention control
When the compressor is not operating or is starting, and the temperature of indoor heat exchanger and/or the room tem-
perature is low or when defrosting is being done, the indoor fan will stop or rotate in Very Low speed.
2. High pressure protection
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the con-
densing pressure from increasing excessively.
When the temperature of indoor heat exchanger becomes too high, the high pressure protection works.
The indoor fan operates following the cold air prevention control. This mode continues until the temperature of indoor
heat exchanger falls.
3. Defrosting
Defrosting starts when the temperature of outdoor heat exchanger becomes too low.
The compressor stops once, the indoor/outdoor fans stop, the 4-way valve reverses, and the compressor re-starts.
This mode continues until the temperature of outdoor heat exchanger rises or the fixed time passes.
7-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
Mode selection
(1) Initial mode
When unit starts the operation with AUTO operation from off;
• If the room temperature is higher than the set temperature, operation starts in COOL mode.
• If the room temperature is equal to or lower than the set temperature, operation starts in HEAT mode.
(2) Mode change
COOL mode changes to HEAT mode when about 15 minutes have passed with the room temperature 2°C below the set
temperature.
HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 2°C above the set
temperature.
NOTE 1
If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating in
(AUTO), cannot change over to the other operating mode (COOL ↔HEAT) and becomes a state of standby.
Refer to NOTE 2 ”FOR MULTI SYSTEM AIR CONDITIONER”.

14
NOTE 2
FOR MULTI SYSTEM AIR CONDITIONER
OUTDOOR UNIT : MXZ series
Multi system air conditioner can connect two or more indoor units with one outdoor unit.
•When you try to operate two or more indoor units with one outdoor unit simultaneously, one for the cool-
ing and the others for heating, the operation mode of the indoor unit that operates earlier is selected. Other
indoor units cannot operate, and operation indicator lamp flashes as shown in the figure below. In this case,
please set all the indoor units to the same operation mode.
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the selected
angle.
Confirming of standard position is performed in the following cases:
(a) When the operation starts or finishes (including timer operation).
(b) When the test run starts.
(c) When standby mode (only during multi system operation) starts or finishes.
(4) VANE AUTO ( ) mode
The microprocessor automatically determines the vane angle and operation to make the optimum room temperature dis-
tribution.
7-5. AUTO VANE OPERATION
1. Horizontal vane
(1) Vane motor drive
These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of
the motor are controlled by pulse signals (approx. 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
Upward
COOL and DRY operation
Vane angle is fixed to Horizontal position or Angle 1.
HEAT operation
Vane angle is fixed to Angle 4.
MSZ-GC22/25/35/50
MSZ-GC60/71
•When indoor unit starts the operation while the defrosting of outdoor unit is being done, it takes a few minutes
(max. 10 minutes) to blow out the warm air.
•In the heating operation, though indoor unit that does not operate may get warm or the sound of refrigerant
flowing may be heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.
OPERATION INDICATOR
or
Lighted
Blinking
Not lighted

15
(5) STOP (operation OFF) and ON TIMER standby
In the following cases, the horizontal vane returns to the closed position.
(a) When OPERATE/STOP (ON/OFF) button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON TIMER is ON standby.
(6) Dew prevention
During COOL or DRY operation with the vane angle at Angle 2 ~ 4 (GC22/25/35/50) / Angle 4 or 5 (GC60/71) when the
compressor cumulative operation time exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew preven-
tion.
(7) SWING ( ) mode
By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically.
(8) Cold air prevention in HEAT operation
The horizontal vane position is set to Upward.
NOTE : When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat OFF, this
control doesn’t work in the indoor unit.
( 10 ) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher.
Also the horizontal vane swings in various cycle.
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air
conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL button is
pressed or LONG button is pressed or change to other operation mode.
(9) To change the air flow direction not to blow directly onto your body. (MSZ-GC22/25/35/50)
To change the airflow
direction When to use this function? COOL/DRY HEAT
Pressing and holding
VANE CONTROL button
for 2 seconds or more,
the horizontal vane
reverses and moves
horizontal position.
Use this function if you don’t
want the air from the indoor
unit to blow directly onto
your body.
• Depending on the shape
of the room, the air may
blow directly onto your
body.
• Press VANE CONTROL
button again to return the
vane to the previously-set
position.
The air conditioner starts
the cooling or drying opera-
tion approx. 3 minutes after
the vane has moved to the
horizontal position.
• When VANE CONTROL
button is pressed again,
the vane returns to the
previously-set position and
the air conditioner starts
the cool or dry operation in
approx. 3 minutes.
The air conditioner starts
heating operation approx.
3 minutes after the vane
has moved to the horizontal
position.
• Sometimes the area
around your feet may
not warm. To warm the
area around the feet, set
the horizontal vane to
(AUTO) or the downward-
blowing position.
• When VANE CONTROL
button is pressed again,
the vane returns to the
previously-set position and
the air conditioner starts
the heat operation in ap-
prox. 3 minutes.
NOTE :
• If you make the airflow not to blow directly onto your body by pressing VANE CONTROL button, the compressor stops
for 3 minutes even during the operation of the air conditioner.
• The air conditioner operates with Very Low speed until the compressor turns on again.
Horizontal
position

16
( 11 ) LONG ( ) MODE (MSZ-GC60/71)
By pressing LONG button indoor fan speed becomes faster than setting fan speed on the remote controller, and the
horizontal vane moves to the position for LONG mode. The remote controller displays “ ”. LONG mode is cancelled
when LONG button is pressed once again or VANE button is pressed or ECONO COOL button is pressed in COOL
mode.
• In the following example, the vertical vane is set to (front.).
COOL / DRY HEAT
Fan speed : Faster
Solid arrow : When the LONG mode is used.
Dotted arrow : When the LONG mode is not used.
61 23 45SWING
2. Vertical vane (MSZ-GC60/71)
(1) Vane motor drive
These models are equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the
motor are controlled by pulse signals (approx. 12 V) transmitted from microprocessor.
(2) The vertical vane angle and mode change as follows by pressing WIDE VANE button.
(3) Positioning
The vane is once pressed to the vane stopper to confirm the standard position and set to the desired angle.
Confirming of standard position is performed in case of follows.
(a) When OPERATE/STOP (ON/OFF) button is pressed (POWER ON/OFF).
(b) When SWING is started or finished.
(c) When the power supply turns ON.
(4) SWING ( ) MODE
By selecting SWING mode with WIDE VANE button, the vertical vane swings horizontally. The remote controller dis-
plays
“ ”.
(5) WIDE ( ) MODE
By selecting WIDE mode with WIDE VANE button, indoor fan speed becomes faster than setting fan speed on the
remote controller ( ). The remote controller displays “ ”.
NOTE : The position of vane angle 3, angle 4 and angle 5 are different in COOL operation and HEAT operation.
Indoor fan speed becomes faster than setting fan speed on the remote controller even when or is select-
ed.

17
7-6. TIMER OPERATION
1. How to set the time
(1) Check that the current time is set correctly.
NOTE : Timer operation will not work without setting the current time. Initially “0:00” blinks at the current time display of
TIME MONITOR, so set the current time correctly with CLOCK SET button.
How to set the current time
(a) Press the CLOCK set button.
(b) Press the TIME SET buttons ( and ) to set the current time.
• Each time FORWARD button ( ) is pressed, the set time increases by 1 minute, and each time BACK
WARD button ( ) is pressed, the set time decreases by 1 minute.
• Pressing those buttons longer, the set time increases/decreases by 10 minutes.
(c) Press the CLOCK set button.
(2) Press OPERATE/STOP (ON/OFF) button to start the air conditioner.
(3) Set the time of timer.
ON timer setting
(a) Press ON TIMER button ( ) during operation.
(b) Set the time of the timer using TIME SET buttons ( and ) .
OFF timer setting
(a) Press OFF TIMER button ( ) during operation.
(b) Set the time of the timer using TIME SET buttons ( and ).
Each time FORWARD button ( ) is pressed, the set time increases by 10 minutes; each time BACKWARD button (
) is pressed, the set time decreases by 10 minutes.
2. To release the timer
To release ON timer, press ON TIMER button ( ).
To release OFF timer, press OFF TIMER button( ).
TIMER is cancelled and the display of set time disappears.
(Example 1) The current time is 8:00 PM.
The unit turns off at 11:00 PM, and on at 6:00 AM.
• OFF timer and ON timer can be used in combination. The timer of the set time that is reached first will operate first.
• “ ” and “ ” display shows the order of OFF timer and ON timer operation.
PROGRAM TIMER
(Example 2) The current time is 11:00 AM.
The unit turns on at 5:00 PM, and off at 9:00 PM.
NOTE : If the main power is turned off or a power failure occurs while ON/OFF timer is active, the timer setting is can-
celled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer
cancelled when power is restored.

18
EMERGENCY OPERATION switch
7-7. EMERGENCY/TEST OPERATION
In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the right side of the
indoor unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of the
remote controller run down. The unit will start and OPERATION INDICATOR lamp will light.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan runs at High
speed and the system is in continuous operation (The thermostat does not work).
After 30 minutes of test run operation, the system shifts to EMERGENCY COOL/HEAT MODE with a set temperature of
24°C. The fan speed shifts to Med..
In the test run or emergency operation, the horizontal vane operates in VANE AUTO ( ) mode.
Emergency operation continues until EMERGENCY OPERATION switch is pressed once or twice or the unit receives any
signal from the remote controller. In case of latter, normal operation will start.
NOTE : Do not press EMERGENCY OPERATION switch during normal operation.
This picture shows MSZ-GC22/25/35.
(Refer to “1. PARTS NAMES AND FUNCTIONS” for the other
models.)
8-1. CAUTIONS ON TROUBLESHOOTING
1. Before troubleshooting, check the following
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and after confirm-
ing the horizontal vane is closed, turn OFF the breaker and/or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the P.C. board.
3) When removing the P.C. board, hold the edge of the board with care NOT to apply stress on the components.
4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
7-8. 3-MINUTE TIME DELAY OPERATION
When the system turns OFF, compressor will not restart for 3 minutes as 3-minute time delay function operates to protect
compressor from overload.
Operation mode COOL HEAT
Set temperature 24°C 24°C
Fan speed Med. Med.
Horizontal vane Auto Auto
The operation mode is indicated by the
Operation Indicator lamp as following
Operation Indicator lamp
EMERGENCY COOL or
↓↓
EMERGENCY HEAT or
↓↓
STOP or
Lighted
Not lighted
Lead wiring Housing point
MSZ-GC22NA MSZ-GC25NA MSZ-GC35NA MSZ-GC50NA MSZ-GC60NA MSZ-GC71NA
TROUBLESHOOTING
8

19
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
2) Before servicing, check that the connector and terminal are connected properly.
3) If the P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the components for
bursting and discoloration.
4) When troubleshooting, refer to 8-2., 8-3. and 8-4.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
RESET button
Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.
NOTE : 1. If RESET button is not pressed, the remote controller may not operate correctly.
2. This remote controller has a circuit to automatically reset the microcomputer when batteries are replaced.
This function is equipped to prevent the microcomputer from malfunctioning due to the voltage drop caused by the
battery replacement.
Press RESET button with a thin instrument, and
then use the remote controller.
Remove the front lid and insert batteries.
Then reattach the front lid.
21 Stopper
Lock.
Left
Insert this end first.
If horizontal vane is not installed correctly, all of the operation indicator lamps will blink.
In this case, install the horizontal vane correctly by following the procedures to .
NOTE : Before installation of the horizontal vane, turn OFF the power supply.
5. How to install the horizontal vane
In procedure lock the
stoppers until they click
into place.
MSZ-GC22/25/35
1
Lock
2
If horizontal vane is not installed correctly, all of the operation indicator lamps will blink.
In this case, install the horizontal vane correctly by following the procedures to .
NOTE : Before installation of the horizontal vane, turn OFF the power supply.
In procedure lock the
stoppers until they click
into place.
MSZ-GC50

20
MSZ-GC22/25/35/50 MSZ-GC60/71
Outline of the function
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (8-4.) disappears, the memorized failure details can
be recalled.
This mode is very useful when the unit needs to be repaired for the abnormality which doesn't recur.
8-2. FAILURE MODE RECALL FUNCTION
1. Flow chart of failure mode recall function for the indoor/outdoor unit
Does upper or left lamp of OPERATION INDICA-
TOR lamp on the indoor unit blink at the interval of
0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal.
Beep is emitted at the same timing as the
blinking of upper or left lamp of OPERA-
TION INDICATOR lamp. 2
Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnor-
malities that can't be recalled with this way.
Confirm if outdoor unit is abnormal according to the detailed outdoor unit
failure mode recall function.
No
Yes
The cause of abnormality cannot be found because the abnormality doesn't recur.
Setting up the failure mode recall function
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button and TOO COOL button on the
remote controller at the same time, press RESET button.
First, release RESET button.
And release the other two buttons after all LCD in operation display section of the
remote controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is
displayed) with the remote controller headed towards the indoor unit. 1
Judgment of indoor/outdoor abnormality
Before blinking, does upper or left lamp of
OPERATION INDICATOR lamp stay ON for 3
seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
The indoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the indoor unit
failure mode table. (Refer to 8-2.2)
Make sure to check at least two consecutive blinking cycles. 2
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
The outdoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the
outdoor unit failure mode table. (Refer to outdoor unit service manual.)
Make sure to check at least two consecutive blinking cycles. 3
Repair the defective parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" mentioned above.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed)
with the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"
mentioned above.
Operational procedure
Yes
(Blinks)
No
(OFF)
NOTE: 1. Make sure to release the failure mode recall function once it's set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2. Blinking pattern when the indoor unit is abnormal:
3.Blinking pattern when the outdoor unit is abnormal:
ON
OFF Beeps
Repeated cycle Repeated cycle
ON
OFF No beep Beeps
Repeated cycle
2.5-second OFF Blinking at 0.5-
second interval
2.5-second OFF 3-second ON Blinking at 0.5-
second interval
Beeps Repeated cycle
2.5-second OFF Blinking at 0.5-
second interval
No beep Beeps
Repeated cycle
2.5-second OFF 3-second ON Blinking at 0.5-
second interval
Repeated cycle
Beeps
1. Regardless of normal or abnormal condition, a short
beep is emitted once the signal is received.