Mitsubishi Heavy Industries Air Conditioner

Introduction

Thank you for choosing a Mitsubishi Heavy Industries Thermal Systems, Ltd. air conditioner. To ensure you enjoy your unit for a long time and it operates reliably, please read this user manual carefully before use. Keep it for future reference and consult it for any operational questions or irregularities.

Your air conditioner may be marked with the following symbol ♻️. This indicates that waste electrical and electronic equipment (WEEE, as per Directive 2012/19/EU) should not be mixed with general household waste. Air conditioners should be sent to an approved treatment facility for reuse, recycling, or reconditioning, and not disposed of with normal waste. Please contact your installer or local authorities for more information.

The symbol printed on the batteries included with your air conditioner product is an information for consumers according to EU Directive 2006/66/EG Article 20 Annex II. Batteries must be disposed of separately from household waste at the end of their life. If a chemical symbol is printed below the symbol shown above, it indicates that the batteries contain heavy metals in a certain concentration: Hg: Mercury (0.0005%), Cd: Cadmium (0.002%), Pb: Lead (0.004%). Please dispose of batteries properly at a battery collection point or designated hazardous waste disposal site.

The sound emission pressure level for the indoor and outdoor units is below 70 dB(A).

Safety Instructions

General Precautions:

• Read these safety instructions carefully before operating the system to ensure proper functioning.
• Keep this user manual handy for future reference. If the unit is passed on to another person, ensure they also receive the manual.

Symbols Explained:

• WARNING ⚠️: Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
• CAUTION ⚠️: Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury or property damage.

Please follow these safety instructions carefully, as your personal safety depends on it.

This unit uses refrigerants R32 or R410A. Information on the refrigerant type is found on the outdoor unit's nameplate.

Symbols used in the text:

• Strictly Prohibited ?
• Follow Instructions Carefully ?
• Ensure Proper Grounding ⏚
• The user manual must be read carefully.
• Important information is found in the user manual and/or installation manual.
• This unit must be installed by qualified personnel according to the installation manual.

Precautions for R32:

This unit uses flammable refrigerant. If refrigerant leaks and an ignition source is present, a fire may occur.

WARNING:

• When disposing of the unit, national regulations must be strictly followed.
• Do not use anything other than the means recommended by the manufacturer for defrosting or cleaning.
• Operate the unit in a room without continuously operating ignition sources (e.g., open flames, gas appliances, electric heaters).
• Do not puncture or incinerate.
• Be aware that refrigerant may be odorless.
• Operate the unit in a well-ventilated area with adequate space for operation.
• Maintenance personnel must possess national or equivalent qualifications.
• The indoor unit must be installed in a room of at least 4.0 m². (This applies to split systems; refer to the outdoor unit's installation sheet for multi-systems.)

Installation Precautions:

WARNING:

• The system is intended for domestic and private use. Use in other environments, such as manufacturing facilities, may lead to malfunctions.
• The system must be installed by your dealer or a qualified installer. Self-installation is not recommended due to the risk of electric shock or fire from improper handling.

CAUTION:

• Do not install near potential flammable gas leaks, as gas leaks can cause fire.
• Ensure a residual current device (RCD) is installed. Do not install a grounded circuit breaker, as this can lead to electric shock.
• Ensure the drain hose is properly connected for water drainage. Improper installation can cause water leakage and damage furniture.
• Ensure the unit is properly grounded. The grounding cable must never be connected to a gas pipe, water pipe, lightning conductor, or telephone ground wire. Improper grounding can cause electric shock.

This product contains fluorinated greenhouse gases. R32 has a Global Warming Potential (GWP) of 675. R410A has a GWP of 2088. The amount of fluorinated greenhouse gas and CO2 equivalent is indicated on the outdoor unit's nameplate.

Operational Precautions:

WARNING:

• Do not let children play with the air conditioner.
• Do not expose yourself to direct cold air for extended periods, as this may cause physical injury or health problems.
• Do not insert objects into the air outlet, as the internal fan rotates at high speed and can cause damage.
• Children aged 8 and above, and persons with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, may use the unit if they have been given supervision or instruction concerning safe use and understand the risks involved. Keep the remote control out of reach of children to prevent accidental ingestion of batteries or other accidents.

CAUTION:

• Use only proper fuses. Using copper wire instead of fuses is strictly prohibited as it can cause failure or fire.
• Do not operate switches with wet hands, as this can cause electric shock.
• Do not swing on or hang from the indoor unit. If it falls, it can cause injury.
• Do not place flammable items like insect repellents or paint cans near the unit, or spray them directly onto the system, as this can cause fire.
• Do not place combustion appliances in the direct airflow of the unit, as this may cause malfunction of the appliance.
• Do not clean the unit with water, as this can cause electric shock. Using a high-pressure cleaner can damage the aluminum fins and reduce performance.
• Do not touch the heat exchanger's aluminum fins, as this can cause injury.
• Do not place electrical appliances or objects under the indoor or outdoor units. Dripping condensation water can soil objects and cause accidents or electric shock.
• Do not operate the system without an air filter, as this can lead to system malfunctions due to heat exchanger blockage and drain pump obstruction.
• If operating the air conditioner with a combustion appliance, ensure regular ventilation of the indoor air. Insufficient ventilation can cause accidents due to oxygen deficiency.
• When cleaning the unit, stop it and disconnect the power supply. Never open the cover while the internal fan is still rotating.
• Do not place objects or allow leaves to accumulate around the outdoor unit. This can allow small animals to enter the unit and come into contact with electrical parts, leading to failure, smoke, or fire.
• Do not immediately disconnect the unit from the power supply after turning it off. Wait at least 5 minutes to prevent water leaks or malfunctions.
• Do not operate the unit via the main power switch, as this can cause fires or water leaks. The fan may start unexpectedly, causing injury.
• Do not pour liquids into the unit or place water containers on it. Water entering the unit can damage insulation and cause electric shock.
• For internal cleaning of the indoor unit, contact your dealer. Do not attempt this yourself. Using unauthorized solvents or incorrect washing methods can damage plastic parts and cause leaks. Damage, smoke, or fire can also occur if solvents come into contact with the unit's electric motor parts.
• In case of thunderstorms or lightning, turn off the unit and disconnect it from the power supply to prevent damage.
• If the power cord is damaged, contact your dealer or a qualified installer. Failure to replace it can cause failure or fire.

Transport and Repair Precautions:

WARNING:

• Do not perform repairs or modifications yourself. Consult your dealer if the unit requires repair. Improper repairs can lead to water leaks, electric shock, or fire.
• For repair information, contact your dealer. Faulty repairs can cause electric shock, fire, etc.
• If the air conditioner needs to be moved, contact your dealer or a qualified installer. Improper installation can cause water leakage, electric shock, fire, etc.
• If you notice anything unusual (e.g., burning smell), turn off the system, disconnect the power supply, and inform your dealer. Continued use under abnormal conditions can lead to malfunction, electric shock, or fire.

If the air conditioner does not cool or heat, there might be a refrigerant leak. Contact your dealer. If refrigerant needs to be refilled, consult your dealer for the correct procedure. If refrigerant comes into contact with skin, it can cause cold burns. Inhaling refrigerant gas excessively can impair nerve functions (dizziness, headaches) or heart functions (irregular heartbeat, palpitations). If refrigerant accidentally drips onto a heater, oven, or hot plate, harmful gases may be produced.

Parts and Functions

Indoor Unit

• Air Inlet
• Air Outlet
• Air Filter: Traps dust and dirt from the indoor unit. (See page 25)
• Refrigerant Pipe Connection and Power Cable
• Display Unit (Remote Control Signal Receiver)
• Drain Hose: Drains water from the indoor unit.
• Wireless Remote Control (See page 11)

Accessories

• Wireless Remote Control
• Holder for Wireless Remote Control
• Wood Screw x 2 (for mounting the remote control holder)
• Battery x 2 (R03 (AAA, Micro))

Outdoor Unit

• Air Inlet (Side and rear surfaces)
• Air Outlet
• Outdoor Unit Fan
• Heat Exchanger

Remote Control Display and Operation

Display Unit

• RUN (HOT KEEP) Light (Green): Lights up during operation. Blinks during air stop due to 'HOT KEEP' and 'CLEAN' operation.
• TIMER Light (Yellow): Lights up during Timer operation.
• HI POWER Light (Green): Lights up during HIGH POWER operation. Blinks during heating preparation.
• ECONO Light (Orange): Lights up during ECONOMY operation.

Buttons

• ON/OFF Button (on unit): Use this switch to turn the unit on or off when the remote control is unavailable.
• MODE Button: Cycles through operating modes (AUTO, COOL, HEAT, DRY, FAN).
• TEMP Button (▲/▼): Adjusts the room temperature.
• HI/ECO Button: Switches between HIGH POWER and ECONOMY modes.
• SILENT Button: Selects SILENT operation.
• FAN SPEED Button: Cycles through fan speed settings (AUTO, ULo, Lo, Me, Hi).
• AIR FLOW (UP/DOWN) Button: Changes the airflow direction (up/down). This button is not used for setting airflow direction.
• ON TIMER Button: Selects ON Timer operation.
• OFF TIMER Button: Selects OFF Timer operation.
• WEEKLY Button: Turns WEEKLY Timer ON/OFF.
• CLEAN Switch: Activates CLEAN operation.
• SLEEP Button: Selects SLEEP operation.
• NIGHT SETBACK Button: Sets NIGHT SETBACK operation.
• SET/Child Lock Button: Used to set timers and Child Lock.
• CANCEL Button: Cancels ON Timer, OFF Timer, and SLEEP operation.
• TIMER Button: Used to set the current time and timers.
• PROGRAM Button: Sets the WEEKLY Timer.
• ACL Switch: Resets the microcomputer.
• TIME SET UP Switch: Used for time setting.

Operation Status Display

When the air conditioner is off, the current time, day of the week, and the preset OPERATING MODE are displayed.

Transmission

After pressing a button on the remote control, point it towards the air conditioner. A signal will be transmitted. Once the signal is received, the air conditioner will emit a reception beep.

Beep Sound for Remote Control

If the preset temperature is 24°C and AUTO mode and airflow are set, a beep sound (PIPI) will be heard. If the air conditioner is turned off using the ON/OFF button (except in CLEAN mode), a beep sound (PI) will be heard. This function is useful for operating the unit in the dark.

Setting the Current Time

When batteries are inserted, the unit automatically enters the time setting mode. Monday and 13:00 are displayed as the current time. Set the correct day of the week and time.

Example: Set to Saturday 10:30.

1. Press the TIME SET UP button using a ballpoint pen or similar. The day of the week display will blink, allowing you to set the day.
2. Press the ▲ or ▼ (TIMER) button. (Example: Set to Saturday)
3. Press the SET button. The display changes from blinking to steady, completing the day setting. The time display will then blink. Ensure you press the button within 60 seconds of the last step, or the day setting will not be applied.
4. Press the ▲ or ▼ (TIMER) button. (Example: Set to 10:30)
5. Press the SET button. The display changes from blinking to steady, completing the setting. Ensure you press the button within 60 seconds of the last step, or the time setting will not be applied.

Note: Timer operations are based on the set time, so ensure it is set correctly. Remote control data is reset when the current time is set. If the remote control batteries are replaced or the ACL switch is pressed, the remote control will reset to its factory settings. The WEEKLY Timer program is not set by default; follow the setup procedure to set it.

Automatic Operation (AUTO)

Automatically selects the operating mode (COOL, HEAT, DRY) based on room temperature when turned on.

1. Press the MODE button. The mode cycles each time the button is pressed. Set to AUTO.
2. Press the ON/OFF button.

To Stop: Press the ON/OFF button again.

Note: AUTO mode will be set by a simple press of the ON/OFF button the next time. If you wish to use a different mode, switch to COOL, HEAT, DRY, or FAN instead.

Setting Airflow Direction (See page 13)

Temperature Setting in AUTO Mode

Temperature can be adjusted even in automatic mode. The ▲ and ▼ buttons allow for 6 positions of adjustment. In AUTO mode, 24°C is preset for heating and cooling.

If it's too cold: Press the ▲ or ▼ (TIMER) button. Each press cycles through: -6, -5, ..., -1, ±0, +1, ..., +6. The display will not change further after +6.

If it's too hot: Press the ▲ or ▼ (TIMER) button. Each press cycles through: +6, +5, ..., +1, ±0, -1, ..., -6. The display will not change further after -6.

FAN SPEED (Fan Speed)

You can adjust the fan speed without using the dehumidifying mode.

1. Press the FAN SPEED button. Each press changes the fan speed.

Note: Changing fan speed from Hi to Lo or ULo may produce audible refrigerant flow noises.

Setting Airflow Direction

Airflow direction (up/down) cannot be set, although the display changes when the 'AIR FLOW' button is pressed.

COOL/HEAT/DRY/FAN Operation

1. Press the MODE button to select the desired mode (COOL, HEAT, DRY, FAN).
2. Press the ON/OFF button.
3. Press the TEMP button. Press the ▲ or ▼ button to set the desired temperature.
4. Press the FAN SPEED button to set the desired fan speed. Fan speed cannot be set during DRY operation.

To Stop: Press the ON/OFF button.

Note: The operating mode can also be set or changed when the air conditioner is not operating.

Temperature Settings for the Air Conditioner

Use within the following operating ranges. Operating outside these ranges may activate protective devices, preventing the unit from working.

Operating the unit for extended periods at over 80% room humidity may cause condensation on the indoor unit's surface, leading to water dripping.

Characteristics of HEAT Operation

Mechanisms and Performance:

• The unit draws in cold outdoor air, transfers it to the indoor space, and heats the room. A characteristic of heat pumps is that heating performance decreases as the outdoor temperature drops.
• It may take some time after starting the air conditioner for warm air to be supplied.
• Use an auxiliary heater in extremely low outdoor temperatures.

Defrosting:

At low outdoor temperatures and high humidity, frost may form on the outdoor unit's heat exchanger, hindering efficient heating. If this occurs, the automatic defrost function activates, interrupting heating operation for 5 to 15 minutes. During defrosting, the indoor and outdoor fans stop, and the RUN light blinks slowly (1.5 sec ON, 0.5 sec OFF). Steam may appear from the outdoor unit during defrosting; this is due to rapid defrosting and is not a malfunction. Heating operation resumes after defrosting is complete.

Timer Operations

SLEEP Timer Operation

After the set time elapses, the unit automatically shuts off. The set temperature is automatically adjusted according to the set time to prevent the room from becoming too cold or too warm.

1. Press the SLEEP button.
2. When the unit is off: SLEEP Timer operation begins with the previous settings. The unit shuts off after the set time.
3. When the unit is on: The unit shuts off after the set time. Each press of this button changes the display: No display (cancel), 2H, 3H, 10H, 9H (in one-hour increments). Example: Unit to stop after 7 hours. The Timer light (yellow) will illuminate.

To change set time: Use the SLEEP button to set a new time.

To cancel: Press the CANCEL button to turn off the SLEEP display.

Note: Unlike SLEEP Timer, automatic temperature adjustment is not possible with OFF Timer operation.

OFF Timer Operation

The unit automatically stops when the set time is reached. Start from Step 1 if the air conditioner is off; start from Step 2 if it is running. Example: Unit to stop at 22:30.

1. Press the ON/OFF button.
2. Press the OFF TIMER button. The OFF TIMER display blinks.
3. Press the ▲ or ▼ (TIMER) button. Each press cycles through time settings in 10-minute increments (0:00-0:10, 0:20, 1:00, 1:10, etc., and 0:00-23:50, 23:40, etc.). Example: Set to 22:30.
4. Press the SET button. The display changes from blinking to steady, completing the setting. The Timer light (yellow) illuminates.

To change set time: Use the OFF TIMER button to set a new time.

To cancel: Press the CANCEL button to turn off the timer display.

Note: The unit stops at the end of the set period. Ensure the button is pressed within 60 seconds of the last step. The current time is not displayed during OFF Timer operation. Unlike SLEEP Timer, automatic temperature adjustment does not occur.

ON Timer Operation

The unit starts 5 to 60 minutes before the set time to reach the optimal room temperature by the scheduled time. ON Timer operation can be set regardless of whether the air conditioner is running or not. Example: Desired room temperature to be reached by 8:00.

1. Press the ON TIMER button. The ON TIMER display blinks.
2. Press the ▲ or ▼ (TIMER) button to set the desired start time (e.g., 8:00).
3. Press the SET button. The display changes from blinking to steady, completing the setting. The Timer light (yellow) illuminates. Operation stops if set during operation.

To change set time: Use the ON TIMER button to set a new time.

To cancel: Press the CANCEL button to turn off the timer display.

Note: Operation begins 5 to 60 minutes before the set time. The Timer light (yellow) extinguishes simultaneously. Ensure the button is pressed within 60 seconds of the last step. Current time is not displayed during ON Timer operation. Pressing ON/OFF after setting ON Timer cancels the setting.

SLEEP Timer & ON Timer Operation

Combined timer operation of SLEEP Timer and ON Timer.

Note: After the SLEEP Timer time elapses, operation stops and resumes 5 to 60 minutes before the ON Timer time. The Timer light does not illuminate at the set ON Timer time.

ON Timer + OFF Timer Operation

Combination of ON and OFF timer operations. Example: Current time 21:00, unit is operating. Unit to stop at 22:30 and restart to reach desired temperature by 8:00.

Note: Timer operation can only be set for the next 24 hours. The Timer light (yellow) illuminates when settings are complete. The set time is displayed on the remote. The unit stops or starts based on the combined timer settings.

Comfort Start: During ON Timer operation, the unit starts slightly earlier to ensure the room reaches the optimal temperature by the set time. The unit checks room temperature 60 minutes prior and starts 5-60 minutes before the ON time, depending on the temperature. This function is available for COOL and HEAT modes (including AUTO), but not for DRY.

SLEEP Timer (Rest Timer): When SLEEP Timer is selected, room temperature is automatically controlled to prevent the room from becoming too cold during cooling or too warm during heating. During cooling, the set temperature decreases by 1°C at the start of SLEEP Timer (if set), then increases by 1°C each hour to be 1°C higher than the current temperature. During heating, the set temperature decreases by 1°C at the start of SLEEP Timer (if set), then decreases by 3°C each hour, becoming 6°C lower than the current temperature after two hours.

WEEKLY Timer Operation

Up to 4 programs (ON Timer / OFF Timer) are available for each day of the week, totaling a maximum of 28 programs per week. Once set, the timer operation repeats the same program each week unless the WEEKLY Timer is cancelled.

WEEKLY Timer ON/OFF Setting: Turn the WEEKLY Timer ON/OFF by pressing the WEEKLY button. Each press cycles through: WEEKLY (ON), No display (OFF). The Timer light (yellow) illuminates when the WEEKLY Timer is active. Remote control data resets upon battery replacement or ACL switch press; the WEEKLY Timer program needs to be set again.

Note: WEEKLY Timer operates independently of whether the unit is running. ON Timer operation is active regardless of unit status. When the set ON Timer time is reached, the remote control adjusts settings accordingly. The following can be set: Mode, Fan Speed, Temperature, ECONOMY, NIGHT SETBACK, SILENT. Comfort Start is not available for WEEKLY Timer ON Timer.

OFF Timer operation is only active when the unit is running. When the set OFF Timer time is reached, the unit stops. If multiple programs are set for the same day, operation starts from the earliest time. If multiple timers (ON, OFF, SLEEP) are active, WEEKLY Timer does not operate. It activates after other timers have finished. ON/OFF timers for the same time on the same day cannot be set. If the WEEKLY Timer is not transmitted, the Timer light will not illuminate even if the WEEKLY button is pressed.

Setting Individual Programs

After setting the current day and time, proceed to set programs.

1. Press the PROGRAM button. The current day and time blink.
2. Press the ▲ or ▼ (TIMER) button to select the day of the week or 'all days'.
3. Press the SET button. The day is set, and the program number blinks.
4. Press the ▲ or ▼ (TIMER) button to select a program number (P1, P2, P3, P4).
5. Press the SET button. If no ON/OFF Timer values are set, both ON and OFF timers blink. If values are set, either ON or OFF illuminates.
6. Press the ON Timer or OFF Timer button. The selected timer is set, and the time display blinks.
7. Press the ▲ or ▼ (TIMER) button to set the time.
8. Set required operating values (mode, fan speed, ECONOMY, SILENT, NIGHT SETBACK) if ON Timer is selected.
9. Press the SET button. The time is set and blinks.
10. Press the PROGRAM button to send the settings to the air conditioner. A reception beep (pip, pip, pip) will sound upon successful transmission. Pressing SET continues from step 2.

Setting Collective Programs

Set the same operating values for the same program number across all days of the week. Select 'all days' in step 2. If individual settings exist for the same program number, they will be overwritten.

Note: If no operation is performed for 60 seconds during setting mode, the changes become invalid, and the mode closes. Program numbers (P1-P4) will blink for 10 seconds. To finalize settings, point the remote at the unit and press PROGRAM. Confirm three reception beeps. If no beep, re-enter setting mode and press PROGRAM.

Cancelling Individual Programs

1. Press the PROGRAM button.
2. Press the ▲ or ▼ (TIMER) button to select the day to be deleted.
3. Press the SET button.
4. Press the ▲ or ▼ (TIMER) button to select the program number to be deleted.
5. Press the CANCEL button. The ON/OFF timer settings are deleted, and '--' is displayed.
6. Press the PROGRAM button to send the cancellation to the unit. All program settings are deleted. Repeat for all programs if necessary.

Cancelling Collective Programs

If the same operating values are set for the same program number across all days, collective cancellation is possible. Select 'all days' in step 2. Step 3 is the same as above. Collective cancellation is not possible if individual settings have been changed or deleted, causing discrepancies.

Confirmation Mode

You can confirm WEEKLY Timer settings.

1. Press and hold the PROGRAM button for 3 seconds or longer. The display blinks, and settings illuminate.
2. Press the ▲ or ▼ (TIMER) button to select the day and program number to confirm. The display starts from the current day. Unset programs show '--'. Pressing PROGRAM in confirmation mode enters setting mode.

Release Procedure: Confirmation mode can be exited by pressing ON/OFF, CANCEL, or SET.

Note: If no operation is performed for 60 seconds in confirmation mode, it will automatically exit.

HIGH POWER/ECONOMY Operation

1. Press the ON/OFF button.
2. Press the HI/ECO button.

HIGH POWER Operation: Pressing the HI/ECO button activates high-performance operation for 15 minutes of strong cooling or heating. The remote displays the mode, and the fan speed indicator may turn off.

Note: During HIGH POWER, room temperature is not controlled. If excessive cooling or heating occurs, press HI/ECO again to cancel. HIGH POWER is not available during DRY or ON/OFF Timer + OFF Timer operation. If set after ON Timer, HIGH POWER starts at the set time. Unit may make noise after HIGH POWER operation.

ECONOMY Operation: Pressing the HI/ECO button activates economy mode to prevent excessive cooling or heating. The unit operates at 1.5°C higher than the set temperature during cooling and 2.5°C lower during heating. The remote displays 'eco', and the FAN SPEED display may turn off.

Note: The unit will revert to ECONOMY mode on the next startup if stopped via ON/OFF, SLEEP, or OFF Timer, or if CLEAN operation ends. ECONOMY mode is cancelled if HI/ECO is pressed again, mode is changed, or NIGHT SETBACK is selected.

NIGHT SETBACK Operation

Maintains a comfortable room temperature, especially during cold seasons when the room is unoccupied (at night or during absence). The air conditioner maintains a constant room temperature of approximately 10°C.

1. Press the NIGHT SETBACK button. Each press cycles through: NIGHT SETBACK ON, No display (OFF).

Release Procedure: Press the NIGHT SETBACK or MODE button to turn off the NIGHT SETBACK display.

Note: During NIGHT SETBACK, the set temperature cannot be adjusted. It is recommended for unoccupied rooms due to potential temperature fluctuations. HIGH POWER and ECONOMY modes cannot be set. Cancelling NIGHT SETBACK returns the unit to its previous operating mode.

SILENT Operation

Reduces noise from the outdoor unit for quieter operation.

1. Press the ON/OFF button.
2. Press the SILENT button. Each press cycles through: SILENT ON, No display (OFF).

Release Procedure: Press the SILENT button to turn off the SILENT display.

Note: SILENT mode may reduce maximum cooling and heating performance. It is not available during DRY or FAN operation. The unit will continue in SILENT mode if restarted after being stopped by ON/OFF, SLEEP, or OFF Timer, or after CLEAN operation. Noise reduction may vary depending on conditions. SILENT control is invalid for SCM multi-systems.

SELF CLEAN Operation

This operation should be performed after AUTO, COOL, and DRY modes to remove moisture from the indoor unit and control mold and bacteria growth.

1. To activate CLEAN operation, press the CLEAN switch using a ballpoint pen tip. Each press cycles through: CLEAN ON, No display (OFF).

Note: CLEAN operation automatically ends after two hours. Press ON/OFF to stop immediately. CLEAN operation is not performed after HEAT, FAN, OFF Timer, or SLEEP operations. The indoor fan runs for approximately two hours during CLEAN operation. The RUN light stays on. Pressing SLEEP or NIGHT SETBACK during CLEAN operation cancels it and switches to that mode. This is not a function to remove existing mold, germs, or dirt.

Automatic Restart Function

What is Automatic Restart? This function records the unit's operating status before a power failure and automatically resumes operation at that exact point once power is restored. Timer settings and HIGH POWER operation are cancelled by this function.

Note: This function is enabled by default. Contact your dealer if you need to disable it. Power failures will clear timer settings, requiring them to be reset.

Tips for Effective Operation

• Set Appropriate Room Temperature: Extremely high or low temperatures are not good for health and waste energy.
• Clean Air Filters Regularly: Clogged filters restrict airflow and lead to inefficient operation. Have filters cleaned by a specialized company.
• Avoid Direct Sunlight and Drafts: Use curtains or blinds against direct sunlight during cooling. Keep windows and doors closed, except for ventilation.
• Set Airflow According to Instructions: Adjust airflow up/down and left/right for even room temperature distribution. Airflow direction cannot be adjusted on the unit itself.
• Operate Unit Only When Necessary: Set timers appropriately.
• Remove Heat Sources: Remove other heat sources from the room whenever possible.

Maintenance

Before Maintenance:

• Disconnect the unit from the power supply.
• Do not spray liquids. Risk of electric shock.
• Clean the unit with a soft, dry cloth.
• Do not touch the heat exchanger's aluminum fins.
• Do not use hot water (40°C or higher), petroleum, paint thinner, gasoline, or cleaning agents, as they can deform or scratch the unit.

During Operation Season:

• Clean Air Filter: Have the filter cleaned by a specialized company. (Filters cannot be washed with water. Dirty filters increase noise and power consumption.)

End of Season:

1. Run the fan for 2 to 3 hours to dry the interior.
2. Turn off the unit and disconnect it from the power supply. (The unit consumes about 2 watts in standby mode; disconnecting saves energy and costs.)
3. Clean and reinsert the filter.
4. Remove batteries from the remote control.

Beginning of Season:

1. Ensure the grounding wiring is not damaged or disconnected.
2. Check the outdoor unit's frame for corrosion or rust.
3. Ensure no obstructions block airflow around the indoor and outdoor unit inlets and outlets.
4. Turn on the unit.
5. Insert batteries into the remote control.

Proper Installation

Adequate Installation:

• Remove any obstructions near the indoor unit that could impede ventilation and functionality.
• Do not install the unit in locations with:
• Risk of flammable gas leaks.
• Significant oil splashes.
• Corrosive gas sources (mineral springs, etc.) or exposure to salty sea breezes (coastal areas). Consult your supplier.
• Keep the air conditioner and remote control at least one meter away from televisions or radios.
• Direct condensation water from the indoor unit to a proper drain.

Consider Operating Noise:

• Ensure the installation location can support the unit's weight and that operating noise is not amplified by vibration. Use vibration dampers between the unit and brackets if building vibrations are transmitted.
• Choose a location where the airflow and operating noise of the indoor and outdoor units do not cause inconvenience to neighbors.
• Avoid obstructions near the outdoor unit's air inlet and outlet, as this can cause malfunctions and increase noise.
• Notify your supplier if any unusual noises occur during operation.

Inspection and Maintenance:

The interior of the air conditioner can become dirty after a few years, reducing performance. In addition to regular cleaning, inspection and maintenance are recommended for longer, more reliable operation. Inquire with your supplier about an inspection and maintenance contract. We recommend off-season inspection and maintenance. If the unit's supply line is damaged, it must be replaced by a manufacturer-equipped service company using special tools.

Troubleshooting

Perform these checks before calling for service:

Unit Does Not Operate at All

• Is the power switched on?
• Is the timer set to 'ON'?
• Is the power off or a fuse blown?

If the unit does not function correctly after checking the above, or if you have doubts after reading page 27, or if something described on page 28 occurs, turn off the power and contact your dealer.

Insufficient Cooling or Heating Performance

• Is the thermostat set to the appropriate temperature?
• Is the air filter clean (not clogged)?
• Are any doors or windows open?

Insufficient Cooling

• Is the room exposed to direct sunlight?
• Is there another heat source in the room?
• Are there too many people in the room?

Hints

Airflow

• No Airflow at Start of Heating: The airflow stops for 5 to 15 minutes to prevent blowing cool air while the heat exchanger warms up (HOT KEEP function).
• No Airflow in DRY Mode: The RUN light blinks slowly (1.5 sec ON, 0.5 sec OFF).
• Defrosting: At low outdoor temperatures and high humidity, the unit may automatically start defrosting. Wait a few minutes. Steam or water may appear from the outdoor unit during defrosting.
• Indoor Fan Stops Periodically: The indoor fan may stop occasionally to prevent re-evaporation of condensed moisture and save energy.

Noises

• Gurgling Noises: Caused by refrigerant flow in the system.
• Clicking Noises: Caused by expansion or contraction within the system.
• Hissing or Clicking: Caused by refrigerant control valves or electronic components.
• Whistling Noise from Outdoor Unit: Comes from the compressor as its speed increases or decreases.
• Hissing Noise from Standby Unit: Occurs when another unit in the system switches off.

Other

• Unit Cannot Be Restarted Immediately After Stopping: Restart is blocked for three minutes to protect the unit. Wait 3 minutes. The microcomputer restarts automatically after this protection period. (RUN light remains on.)
• Steam During COOL Operation: May occur when room temperature and humidity are very high; it disappears as temperature and humidity decrease.
• Odors: Air blown out may have an odor due to residues from smoke or cosmetics inside the unit.
• Unit Does Not Restart After Power Failure: If automatic restart is not enabled, the unit will not start automatically. Use the remote control to turn it on.
• Remote Control Signals Not Received: If direct sunlight or other strong light falls on the unit's display, signals may not be received correctly. Prevent direct sunlight or strong light exposure.
• Moisture on Air Outlet Grill: If the unit operates in high humidity for extended periods, moisture may form and drip from the outlet grill.
• Fan Does Not Stop Immediately: Indoor fan: Does not stop for 2 hours if CLEAN operation is set. Outdoor fan: Stops for about 1 minute to protect the unit.
• RUN Light Stays On After Stopping: The RUN light is on during CLEAN operation and turns off when CLEAN operation ends.

Contact Your Dealer

Contact your dealer immediately and notify them if you experience any of the following:

• Continuous switch or fuse operation.
• Power cord becomes hot, or insulation is broken.
• Fuse repeatedly blows.
• Interference with TV, radio, or other devices.
• A switch is not functioning properly.
• Unusual noises during operation.

CAUTION: If the power cord is damaged, have it replaced by a qualified technician to avoid accidents.

If foreign objects enter the indoor unit via air vents and the unit cannot be operated, contact your dealer. If the RUN and TIMER indicator lights blink rapidly (0.5s ON; 0.5s OFF) but do not stay lit, turn off the unit, wait 3 minutes, then turn it on again using the remote control. If the problem persists, contact your dealer.

Multi-Unit Operation

Simultaneous Operation: Units cannot operate in different modes simultaneously (e.g., COOL and HEAT). The first unit turned on takes priority; subsequent units will default to fan mode. To give priority to a later unit, turn off the first unit or match its mode to the later unit. The RUN light illuminates if other indoor units are operating in different modes.

Automatic Operation: If the remote control is set to AUTO mode, the unit automatically selects COOL, DRY, or HEAT based on room temperature. In multi-unit operation, modes may switch automatically based on room temperature, potentially causing the outdoor unit to shut down. In such cases, select COOL or HEAT manually instead of AUTO.

Refrigerant (Oil) Preparation: If indoor units are not operated for an extended period, cooling or heating performance may temporarily decrease. This is to regulate refrigerant (oil) preparation in the idle indoor units. You may hear refrigerant flowing from the idle units.

Self-Diagnosis Function

We continuously strive to improve our customer service by incorporating diagnostic capabilities to identify potential faults:

Company Information

MITSUBISHI HEAVY INDUSTRIES THERMAL SYSTEMS, LTD.
2-3, Marunouchi 3-chome, Chiyoda-ku, Tokyo, 100-8332, Japan
http://www.mhi-mth.co.jp/en/

MITSUBISHI HEAVY INDUSTRIES AIR-CONDITIONING EUROPE, LTD.
5 The Square, Stockley Park, Uxbridge, Middlesex, UB11 1ET, United Kingdom
Tel: +44-333-207-4072
Fax: +44-333-207-4089
http://www.mhiae.com/

MITSUBISHI HEAVY INDUSTRIES AIR-CONDITIONERS AUSTRALIA, PTY. LTD.
Block E, 391 Park Road, Regents Park, NSW, 2143 PO Box 3167, Regents Park, NSW, 2143
Tel: +61-2-8774-7500
Fax: +61-2-8774-7501
http://www.mhiaa.com.au