Mitsubishi Heavy Industries Air-Conditioner User's Manual

Introduction

Thank you for choosing a Mitsubishi Heavy Industries Thermal Systems, Ltd. air conditioner. For optimal performance and longevity, please read this user manual carefully and follow all instructions. Keep it in a safe place for future reference.

Environmental Information:

• ♻️ WEEE Directive: This symbol indicates that the product is subject to the Waste Electrical and Electronic Equipment (WEEE) directive. It must not be mixed with general household waste and requires disposal at authorized facilities for reuse, recycling, and recovery.
• ? Battery Disposal: The symbol on batteries complies with EU Directive 2006/66/CE. Batteries must be disposed of separately from household waste. If heavy metals (Hg, Cd, Pb) are present, they are indicated. Dispose of batteries correctly at designated collection points or recycling centers.

Noise Level: The sound pressure emission level for both indoor and outdoor units is less than 70 dB(A).

Safety Precautions

General Warnings:

• ⚠️ AVISO (WARNING): Indicates a potentially hazardous situation which, if not avoided, could result in serious injury or death.
• ⚠️ CUIDADO (CAUTION): Indicates a potentially hazardous situation which, if not avoided, may result in personal injury or property damage.

Symbols Used in Manual:

• ?: Strictly Prohibited
• ?: User Manual Must Be Read Carefully
• ℹ️: Information Included in User Manual and/or Installation Manual
• ?️: Equipment Must Be Handled by a Qualified Service Technician
• ?: Risk of Fire / Flammable Gas
• ⚡: Risk of Electric Shock
• ?: Risk of Water Leakage

Specific Safety Instructions:

• For R32 Refrigerant: This equipment uses flammable refrigerants. A leak in the presence of an ignition source can cause ignition.
• Installation Precautions:
  • Intended for domestic and residential use only.
  • Must be installed by a qualified dealer or technician. Incorrect installation can lead to water leaks, electric shock, or fire.
  • Do not install where flammable gas may leak, as it can cause fires.
  • Ensure a proper leakage circuit breaker with grounding is installed. Failure to do so may result in electric shock.
  • Ensure the drainage hose is installed correctly for water to flow out. Improper installation can cause water spills.
  • Ensure the system has adequate grounding. Never connect ground wires to gas pipes, water pipes, lightning rods, or telephone ground cables.
• Operation Precautions:
  • Keep children away from the air conditioner.
  • Do not expose yourself to cold airflow for extended periods, as it may affect your health.
  • User cleaning and maintenance should not be performed by unsupervised children.
  • Do not insert objects into air outlets, as the internal fan rotates at high speed, posing an injury risk.
  • The appliance can be used by children aged 8 and above, and persons with reduced physical, sensory, or mental capabilities, if supervised or instructed on safe use and risks.
  • Store the remote control out of children's reach to prevent accidental ingestion of batteries.
  • Use only authorized fuses. Using steel or copper wire instead of a fuse is prohibited and can cause serious malfunction or fire.
  • Do not handle switches with wet hands, as this can cause electric shock.
  • Do not balance or hang on the indoor unit; it may fall and cause injury.
  • Do not place flammable insecticides or spray paint near the unit, or spray them directly onto the system, as this may cause fire.
  • Do not expose combustion devices directly to the unit's airflow, as it may cause malfunction.
  • Do not wash the unit with water, as it may cause electric shock. High-pressure washers can damage aluminum fins and reduce performance.
  • Do not use the unit for storing food, plants, animals, precision devices, or artwork. It is intended for common household rooms.
  • Do not place water containers (e.g., vases) on the unit. Water ingress can damage the installation and cause electric shock.
  • Do not install the unit where airflow is directed at plants or animals, as it may affect their health.
  • Do not sit on or place objects on the unit. If the unit falls or objects fall from it, people nearby may be injured.
  • Periodically check the unit's support structure. Promptly repair any damage to prevent the unit from falling and causing injury.
  • Do not touch aluminum fins on the heat exchanger, as it may cause injury.
  • Do not place electrical appliances or household items below the indoor or outdoor unit. Condensation dripping from the unit may stain items and cause accidents or electric shock.
  • Do not operate the system without the air filter. This can cause system malfunctions due to heat exchanger blockage and drainage pump issues.
  • When using the air conditioner with a combustion device, ensure regular indoor ventilation to prevent oxygen deficiency.
  • When cleaning, stop the unit and disconnect the power supply. Never open the panel while the internal fan is spinning.
  • Do not disconnect the power supply immediately after stopping operation. Wait at least 5 minutes to avoid water leakage or malfunction.
  • Do not control the system using the main power switch, as it can cause fire or water leakage and unexpected fan operation.
  • Do not place liquids or water containers inside the unit. Water ingress can damage the installation and cause electric shock.
  • Contact your supplier for interior cleaning. Do not attempt it yourself, as unauthorized detergents or improper washing methods can damage plastic components, cause leaks, or lead to damage, smoke, or fire if detergent contacts electrical parts or the motor.
  • Disconnect the unit and power supply during thunderstorms or if lightning is a risk, as it may damage the unit.
  • If the power cord is damaged, contact your dealer or a qualified technician for replacement to prevent serious malfunction or fire.
• Relocation or Repair Precautions:
  • Do not perform any repairs or modifications. Contact your dealer if the unit requires repair. Unauthorized repairs can cause water leaks, electric shock, or fire.
  • Contact your supplier for repair information. Improper repairs can lead to electric shock or fire.
  • For relocation, contact your dealer or a qualified technician. Improper installation can cause water leaks, electric shock, or fire.
  • If you notice any abnormality (e.g., burning smell), stop the system, disconnect the power supply, and consult your dealer. Continued operation under abnormal circumstances can lead to malfunction, electric shock, or fire.
  • If the air conditioner cannot cool or heat, it may have a refrigerant leak. Contact your supplier. Refrigerant addition requires appropriate instructions from your dealer. Direct contact with refrigerant can cause frostbite. Inhaling excessive refrigerant gas can cause nerve damage (dizziness, headache) or cardiac issues (tachycardia, palpitations). If refrigerant leaks near a heat source (heater, oven, stove), harmful gases may be produced.

Parts Identification

Indoor Unit

• Air Inlet: [Air Intake Grille]
• Air Outlet: [Air Outlet Vent] - Air is blown out from here.
• Air Filter: [Air Filter] - Traps dust and dirt from incoming air. (See page 25)
• Refrigerant Pipe and Electrical Wiring Connection: [Connection Point]
• Unit Display Section (Remote Control Signal Receiver): [Signal Receiver]
• Drain Hose: [Drain Hose] - Drains water from the indoor unit.

Accessories

• Wireless Remote Control: [Remote Control]
• Wireless Remote Control Holder: [Remote Control Holder]
• Phillips Screwdriver x2: [Screwdriver] - For mounting the remote control holder.
• Batteries x2 (R03/AAA, Micro): [Batteries]

Outdoor Unit

• Air Inlet: [Air Inlet] (on side and rear surfaces)
• Air Outlet: [Air Outlet]
• Outdoor Unit Fan: [Outdoor Fan]
• Heat Exchanger: [Heat Exchanger]

Remote Control Operation

Unit Display Section

• RUN Light (Green): Illuminates during operation. Flashes during "HEAT KEEP" and "CLEAN" operation pause.
• TIMER Light (Yellow): Illuminates during TIMER operation.
• HI POWER Light (Green): Illuminates during HIGH POWER operation. Flashes during preheating.
• ECONO Light (Orange): Illuminates during ECONOMY operation.
• Remote Control Signal Receiver: [Signal Receiver]
• Unit ON/OFF Button: For manual operation when the remote is unavailable.

Sound Signals

A "PIPI" sound indicates automatic settings are selected. A "PI" sound occurs when pressing the ON/OFF button (except in CLEAN mode). This feature is useful for operating the unit in the dark.

Airflow Configuration

Diagram illustrating airflow direction settings.

Set Temperature

Displays the target temperature.

Remote Control Handling

Battery Replacement

Signs of Low Batteries: No reception sound, display disappears.

1. Remove the cover and used batteries.
2. Insert new batteries (R03/AAA, Micro x2), observing polarity.
3. Close the cover.
4. Press the ACL switch with a pen tip.

Notes: Do not mix new and old batteries. Remove batteries if the remote will not be used for an extended period. Recommended battery life is 6-12 months. Using unspecified batteries may cause leakage and damage.

Remote Control Holder

The remote control can be mounted on a wall or column using the provided holder. Ensure proper signal reception before installation.

Handling Warnings

• Avoid high temperatures (e.g., near heaters or ovens).
• Do not place obstacles between the remote control and the unit's display section.
• Do not expose the remote control to direct sunlight or strong light.
• Do not spill liquids on the remote control.
• Handle the remote control with care; do not drop it.
• Do not place heavy objects on or step on the remote control.

Remote Control Failure

Check Batteries: Replace batteries if they are low. If the problem persists, use the temporary operation function and contact your supplier for remote control verification.

Temporary Operation

The unit's ON/OFF button on the display section allows temporary operation when the remote control is not in use. The operation mode defaults to AUTO, and Fan Speed defaults to AUTO.

Installation and Operation

Installing Two Air Conditioners in the Same Room

This section describes how to set the remote control and indoor unit when two air conditioners are installed in the same room and are not operated by the same remote control.

Child Lock

This function locks the remote control operation to prevent accidental use. Press and hold the SET button for 3 or more seconds to activate/deactivate. When active, only the ON/OFF button can be used. Temperature and fan speed settings cannot be changed while locked.

Remote Control Operation Details

This section details the functions of each button on the remote control and the unit's display.

• MODE Button: Selects operation mode (AUTO, COOL, HEAT, DRY, FAN).
• TEMP Buttons (▲/▼): Adjusts the set temperature.
• HI/ECO Button: Selects HIGH POWER or ECONOMY mode.
• SILENT Button: Activates SILENT operation.
• ON TIMER Button: Selects the ON TIMER function.
• OFF TIMER Button: Selects the OFF TIMER function.
• WEEKLY Button: Toggles the WEEKLY TIMER ON/OFF.
• CLEAN Switch: Selects the SELF CLEAN operation.
• SLEEP Button: Selects the SLEEP operation.
• SET/Child Lock Button: Used to set timers and activate Child Lock.
• CANCEL Button: Cancels timer operations (ON, OFF, SLEEP).
• TIMER Buttons: Used for setting the current time and timer functions.
• PROGRAM Button: Sets the WEEKLY TIMER.
• ACL Button: Resets the microcomputer.
• TIME SET UP Switch: Used to set the current time.

Transmission Procedure: Point the remote control at the unit's display section and press buttons. A "bip" sound confirms correct signal reception.

Setting Time and Modes

Setting Current Time

After inserting batteries, the current time defaults to Monday, 13:00. Use the TIME SET UP switch, TIMER (▲/▼) buttons, and SET button to set the correct day of the week and time.

AUTO Mode Operation

When the unit is powered on, it automatically selects the operation mode (COOL, HEAT, DRY) based on the ambient temperature.

Temperature, Fan Speed, and Airflow

Temperature Adjustment in AUTO Mode

You can adjust the temperature even during AUTO mode operation using the ▲/▼ (TIMER) buttons. The temperature can be adjusted in 6 levels. The default setting for heating and cooling in AUTO mode is 24°C.

FAN SPEED (VENTILATION SPEED)

You can select the fan speed for your air conditioner, except in dehumidification mode. Press the FAN SPEED button repeatedly to cycle through AUTO, ULo, Lo, Me, Hi. Note: Fan speed cannot be set in DRY mode.

Airflow Direction

Note: The airflow direction may not be adjustable, or the display may change when the "AIR FLOW" button is pressed, but the actual direction may not change.

Operation Modes

COOL/HEAT/DRY/FAN Operation

Follow these steps to operate the unit:

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 (▲ or ▼) to set the desired temperature.
4. Press the FAN SPEED button to select the fan speed.

Operating Temperature Limits: The unit has specific operating temperature limits. Operating outside these limits may activate protection devices and stop the unit.

HEAT Mode Characteristics

Mechanism: The unit extracts heat from the cold outdoor air and transfers it indoors for heating. The heating capacity decreases as the outdoor temperature drops. It may take time to supply warm air after starting. In extremely low outdoor temperatures, supplemental heating may be advisable.

Defrosting: In low outdoor temperatures and high humidity, frost may form on the outdoor unit's heat exchanger, hindering efficient heating. The automatic defrost function activates, pausing heating for 5-15 minutes. During defrosting, the indoor and outdoor fans stop, and the RUN light flashes slowly. The outdoor unit may emit vapor, which is normal. Heating resumes after defrosting.

Timers

SLEEP TIMER

The unit automatically stops after a set time. The temperature is adjusted automatically to prevent excessive cooling or heating.

OFF TIMER

The unit automatically stops at the set time.

ON TIMER

The unit starts operation 5 to 60 minutes before the set time, ensuring the room reaches the desired temperature by the target time.

Combined Timers (SLEEP + ON, ON + OFF)

Instructions for setting combined timer operations.

Comfort Start-up

With ON TIMER, the unit starts operation slightly before the set time to ensure the room reaches the desired temperature by the ON time. The unit checks the room temperature 60 minutes before the ON time and adjusts the start time accordingly.

SLEEP TIMER Details

During cooling, the set temperature decreases by 1°C initially, then increases by 1°C per hour. During heating, the set temperature decreases by 1°C initially, then by 3°C after one hour and 6°C after two hours.

Weekly Timer

WEEKLY TIMER Operation

Up to 4 programs per day, and a maximum of 28 programs per week, can be set. Once set, the timer repeats weekly unless canceled.

Setting Weekly Timer ON/OFF

Press the WEEKLY button to toggle the Weekly Timer ON or OFF. The yellow TIMER light illuminates when ON.

Setting Individual/Group Programs

Instructions for setting specific programs for individual days or applying the same program to all days of the week.

Canceling Weekly Timer

Procedures for canceling individual or group program settings.

Confirmation Mode

Allows confirmation of the set WEEKLY TIMER programs.

Special Operations

HIGH POWER/ECONOMY

HIGH POWER: Provides powerful cooling/heating for 15 minutes. The remote displays HI POWER, and FAN SPEED display disappears. Operation stops automatically after 15 minutes or if HIGH POWER is canceled.

ECONOMY: Saves energy by slightly adjusting the temperature (1.5°C higher in cooling, 2.5°C lower in heating). The remote displays "eco", and FAN SPEED display disappears.

NIGHT SETBACK

Maintains a comfortable room temperature (~10°C) during absence or at night, saving energy. Temperature settings cannot be adjusted during this operation.

SILENT Operation

Reduces fan noise for quieter operation. Note that cooling/heating performance may be reduced. SILENT operation is not available in DRY or FAN modes.

SELF CLEAN

Operates for approximately 2 hours after cooling or heating to dry the indoor unit and prevent mold and bacteria growth. The RUN light illuminates during operation. Pressing SLEEP or NIGHT SETBACK cancels the CLEAN operation.

Auto Restart Function

If power is interrupted, the unit automatically restarts with its previous operating state once power is restored. Timer settings are canceled during a power outage.

Tips for Efficient Operation

Maintain appropriate room temperature. Clean air filters regularly. Avoid direct sunlight and drafts. Keep heat sources away from the unit during cooling.

Maintenance

Before Maintenance

Always disconnect the power supply. Clean the unit with a soft, dry cloth. Do not use liquids or abrasive materials.

During Operation

Clean the air filters regularly. Professional cleaning is recommended.

End of Operation Period

Run the fan for 2-3 hours to dry the interior. Stop the unit and disconnect the power supply. Remove batteries from the remote control.

Start of Operation Period

Ensure grounding connections are intact. Check the outdoor unit base for corrosion. Ensure no obstructions block airflow to the unit. Connect power supply. Insert batteries into the remote control.

Installation and Troubleshooting

Correct Installation

Choose a suitable location that can support the unit's weight and minimize noise. Avoid installing near sources of flammable gas or oil splashes. Ensure the unit is at least 1 meter away from TVs or radios. Ensure proper drainage.

Inspection and Maintenance

Regular inspections are recommended for optimal performance and longevity. Contact your supplier for paid inspection and maintenance services.

Troubleshooting

Unit Not Operating: Check if the power switch is on, if the timer is set, or if there's a power outage or tripped breaker/fuse.

Weak Cooling/Heating: Verify thermostat settings, check if air filters are clean, ensure doors/windows are closed, and minimize direct sunlight or heat sources.

Airflow Issues: If no air is expelled during heating, the unit may be in defrost mode or the filter may be dirty.

Noise: Various sounds are explained, including gurgling (refrigerant flow), cracking (expansion/contraction), interference/clicking (control valves/electronics), hissing (compressor speed change), and sounds from other units.

Various Issues: Unit not restarting immediately (3-minute protection timer), vapor expulsion during COOL mode, slight odor, unit not restarting after power outage (check Auto Restart setting), remote signal reception issues (avoid direct sunlight on display), humidity formation, fan behavior after operation stop, and RUN light status.

Contact and Multi-AC Information

Contact Your Supplier

Immediately disconnect the power switch and inform your supplier if the fuse or switch trips continuously, the cable becomes extremely hot, the cable coating cracks, electrical appliances malfunction due to the unit, switches malfunction, or strange noises occur. If foreign objects enter the unit and the louvers stop working, contact the product representative. If the RUN and TIMER lights flash rapidly and the unit does not function, disconnect power, wait 3 minutes, reconnect, and try restarting. If the problem persists, contact your supplier.

Multi-Air Conditioner Operation

Simultaneous Operation: Units cannot operate in different modes (e.g., COOL and HEAT) simultaneously. The first unit operated takes priority. To match modes, stop the prioritized unit or change its mode. The RUN light illuminates when indoor units operate in different modes.

Automatic Operation: In AUTO mode, the unit selects COOL, DRY, or HEAT based on temperature. When operating multiple indoor units, modes may change automatically, potentially interrupting outdoor unit operation. It is recommended to use COOL or HEAT mode instead of AUTO when using multiple indoor units.

Refrigerant (Oil) Recovery Operation: If indoor units are not operated simultaneously for extended periods, performance may temporarily decrease due to oil recovery within the stopped unit. Refrigerant flow noise may be heard.

Self-Diagnosis Function

The unit features a self-diagnosis system. Flashing RUN and TIMER lights indicate specific problems. For example:

• RUN light flashing 1 time: Heat exchanger sensor 1 error.
• RUN light flashing 2 times: Ambient temperature sensor error.
• RUN light flashing 3 times: Heat exchanger sensor 3 error.
• RUN light flashing 4 times: Drainage error.
• RUN light flashing 5 times: Active filter voltage error.
• RUN light flashing 6 times: Indoor unit fan motor error.
• RUN light flashing 7 times: Insufficient refrigerant or closed service valve.
• TIMER light flashing 1 time: Outdoor temperature sensor error.
• TIMER light flashing 2 times: Heat exchanger fluid pipe sensor error.
• TIMER light flashing 4 times: Discharge pipe sensor error.
• TIMER light flashing 5 times: Suction pipe sensor error.
• RUN light flashing continuously: Compressor overload, power transistor error, etc.

Refer to the manual for a complete list of error codes and their causes.

Company Information

Contact details for Mitsubishi Heavy Industries:

• Mitsubishi Heavy Industries Thermal Systems, Ltd.
• 16-5 Konan 2-chome, Minato-ku, Tokyo, 108-8215, 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.
• 9C Commercial Road Kingsgrove NSW 2208 PO BOX 318 Kingsgrove NSW 1480
• Tel: +61-2-8571-7977
• Fax: +61-2-8571-7992
• http://www.mhiaa.com.au