Fujitsu AST12 SERIES Operating Manual
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Fujitsu AST12 SERIES Operating Manual

Fujitsu AST12 SERIES Operating Manual

Air conditioner wall mounted type
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AIR CONDITIONER

WALL MOUNTED TYPE

Indoor Unit
AST7
SERIES
AST9
SERIES
AST12
SERIES
KEEP THIS MANUAL
FOR FUTURE REFERENCE
FUJITSU GENERAL LIMITED

OPERATING MANUAL

P/N9373538035
Table of Contents
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Frequently Asked Questions (27)

  • How to clean the air filter of a Fujitsu AST7 SERIES Air Conditioner?

    To clean the air filter:

    1. Open the intake grille and remove the air filter. Lift up the air filter's handle, disconnect the two lower tabs, and pull it out.
    2. Remove dust with a vacuum cleaner or by washing. If you wash the filter, be sure to allow it to dry thoroughly in a shaded place before reinstalling.
    3. Replace the air filter and close the intake grille. Align the sides of the air filter with the panel, and push in fully, making sure the two lower tabs are returned properly to their holes in the panel.

    Air filters should be cleaned every two weeks during normal use. If dirt is allowed to accumulate, it will reduce airflow, lower operating efficiency, and increase noise.


    For more information, see page 14 of the manual.
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  • Why is my Fujitsu AST7 SERIES Air Conditioner not blowing cold air?

    If your air conditioner is not blowing cold air, consider the following:

    • Check if the air filter is dirty. A dirty filter can reduce performance.
    • Ensure the air conditioner's intake grille or outlet port is not blocked.
    • Verify that the room temperature settings (thermostat) are adjusted correctly.
    • Check if a window or door is open, allowing warm air to enter.
    • In Cooling operation, ensure there are no heating apparatus or computers inside the room, or too many people, which can increase the room temperature.
    • Check if the unit is set for SUPER QUIET operation, which reduces airflow for quieter operation and may affect cooling performance.

    For more information, see page 18 of the manual.
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  • Why is my Fujitsu AST7 SERIES Air Conditioner leaking water?
    Water leakage from the indoor unit can occur if the air conditioner is used for long periods under high-humidity conditions, causing condensation to form on the surface of the indoor unit and drip onto the floor or other objects. This can also happen if the Air Flow Direction Louvers are left in the heating range for more than 30 minutes during Cooling or Dry modes, as water vapor may condense and drip.
    For more information, see pages 12 and 20 of the manual.
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  • Why won't my Fujitsu AST7 SERIES Air Conditioner turn on?

    If your air conditioner won't turn on, check the following:

    • Verify if the circuit breaker has been turned off.
    • Check if there has been a power failure.
    • See if a fuse has blown out or a circuit breaker has tripped.
    • Check if the timer is operating, which might delay startup.
    • If the unit was stopped and then immediately started again, the compressor will not operate for about 3 minutes to prevent fuse blowouts.
    • If the power supply plug was disconnected and then reconnected, the protection circuit will operate for about 3 minutes, preventing unit operation during that period.

    For more information, see page 18 of the manual.
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  • Why is my Fujitsu AST7 SERIES Air Conditioner not heating?

    If your air conditioner is not heating, consider the following:

    • The unit operates on a heat-pump principle, absorbing heat from outdoor air and transferring it indoors. Its operating performance is reduced as outdoor air temperature drops. If heating performance is insufficient, use this air conditioner in conjunction with another heating appliance.
    • Heat-pump air conditioners heat the entire room by recirculating air, so it may take some time for the room to heat up after starting the air conditioner.
    • Ensure the thermostat is set to a temperature higher than the current room temperature. The Heating mode will not operate if the thermostat is set lower than the actual room temperature.
    • If the air filter is dirty, it can reduce performance.
    • Ensure the air conditioner's intake grille or outlet port is not blocked.
    • Check if a window or door is open.
    • If the unit is set for SUPER QUIET operation, heating performance will be reduced somewhat.
    • During Heating operation, the unit may temporarily stop for 7 to 15 minutes as the Automatic Defrosting mode operates. During this time, the OPERATION indicator lamp (red) will flash.
    • When Heating operation is started, the fan speed may be temporarily very low to allow internal parts to warm up.
    • If the room temperature rises above the thermostat setting during Heating operation, the outdoor unit will stop, and the indoor unit will operate at very low fan speed. To warm the room further, set the thermostat to a higher setting.
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  • Why is my Fujitsu AST7 SERIES Air Conditioner not responding to the remote control?

    If your air conditioner is not responding to the remote control, check the following:

    • The remote control unit's batteries might be dead.
    • The remote control unit's batteries might not be loaded properly.
    • Ensure the remote control unit is pointed at the signal receiver on the air conditioner.
    • The operating range of the remote control is about 7 meters. If no beep is heard when pressing a button, press it again.
    • Use of other electrical appliances or nearby wireless radio transmitters may cause the air conditioner to malfunction. In such a case, temporarily disconnect the power supply plug, reconnect it, and then use the remote control unit to resume operation.
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  • How to service a Fujitsu AST7 SERIES Air Conditioner?

    This unit contains no user-serviceable parts. Always consult authorized service personnel for repairs. If the power supply cord is damaged, it should only be replaced by authorized service personnel, as special purpose tools and specified cords are required. In case of a malfunction (e.g., burning smell), immediately stop operation, turn off the circuit breaker, and consult authorized service personnel.

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  • Why is my Fujitsu AST7 SERIES Air Conditioner not working after a power outage?

    The air conditioner has an AUTO Restart function. If the power is interrupted by a power failure, the unit will automatically restart in its previous mode once power is restored. If a power failure occurs during TIMER operation, the timer will be reset, and the unit will begin or stop operation at the new time setting. If this type of timer fault occurs, the TIMER Indicator Lamp (green) will flash.

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  • What can I do to make my Fujitsu AST7 SERIES Air Conditioner cool more effectively?

    To make your air conditioner cool more effectively, consider the following:

    • Ensure the air filter is clean. A dirty filter can reduce performance.
    • Make sure the air conditioner's intake grille or outlet port is not blocked.
    • Adjust the room temperature settings (thermostat) correctly.
    • Close any open windows or doors to prevent warm air from entering.
    • In Cooling operation, minimize heat sources in the room such as heating apparatus, computers, or too many people.
    • Avoid setting the unit to SUPER QUIET operation, as this mode reduces airflow for quieter operation and may affect cooling performance.

    For more information, see page 18 of the manual.
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  • How do I reset the control panel of my Fujitsu AST7 SERIES Air Conditioner?

    To perform a reset on the remote control unit, press the ACL button with the tip of a ballpoint pen or other small object. This should be done if the remote control unit's operating range becomes appreciably reduced after replacing batteries.

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  • How to clean the Fujitsu AST7 SERIES Air Conditioner unit?

    Before cleaning, turn off the air conditioner and disconnect the power supply cord. Ensure the intake grille is installed securely. When removing and replacing air filters, avoid touching the heat exchanger to prevent injury.

    To clean the Intake Grille:

    1. Remove the intake grille by placing fingers at both lower ends, lifting forward, and pulling past the intermediate catch to open it horizontally.
    2. Clean with water: Remove dust with a vacuum cleaner, wipe the unit with warm water, and dry with a clean, soft cloth.
    3. Replace the intake grille by pulling the knobs all the way, holding the grille horizontally, and setting the left and right mounting shafts into the bearings at the top of the panel.

    To clean the Air Filter:

    1. Open the intake grille and remove the air filter by lifting its handle, disconnecting the two lower tabs, and pulling it out.
    2. Remove dust with a vacuum cleaner or by washing. If washing, allow it to dry thoroughly in a shaded place before reinstalling.
    3. Replace the air filter and close the intake grille by aligning the sides of the air filter with the panel and pushing it in fully, ensuring the two lower tabs are properly returned to their holes.

    Air filters should be cleaned every two weeks during normal use. If dirt accumulates, it can reduce airflow, lower operating efficiency, and increase noise.


    For more information, see page 14 of the manual.
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  • How do I switch between cooling and heating modes on my Fujitsu AST7 SERIES Air Conditioner?

    To switch between operating modes, press the MASTER CONTROL button on the remote control. Each time the button is pressed, the mode will change in the following order: AUTO → COOL → DRY → HEAT (for Heat & Cool models) → FAN. The display will reappear about three seconds later.

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  • How do I interpret the various indicator lights on my Fujitsu AST7 SERIES Air Conditioner?

    The air conditioner has the following indicator lamps:

    • The OPERATION Indicator Lamp (red):
      • Lights when the unit is operating.
      • Flashes slowly during the defrosting operation.
      • Flashes quickly (1 second on, 1 second off) when the selected operating mode cannot be used.
    • The TIMER Indicator Lamp (green):
      • Flashes when the timer is operating, indicating a fault with the timer setting.
    • The SWING Indicator Lamp (orange):
      • Lights when the swing operation is active.
      • Goes out when swing operation is stopped.

    For more information, see page 5 of the manual.
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  • How to use the remote control for the Fujitsu AST7 SERIES Air Conditioner?

    To use the remote control unit, point it at the signal receiver on the air conditioner. A beeping sound will be heard when a signal is properly received. The operating range is about 7 meters. If no beep is heard, press the remote control unit button again. The remote control unit allows for convenient control of air conditioner operation.


    For more information, see pages 3, 5 and 6 of the manual.
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  • How to reset a Fujitsu AST7 SERIES Air Conditioner using the remote?

    To perform a reset on the remote control unit, press the ACL button with the tip of a ballpoint pen or other small object. This should be done if the remote control unit's operating range becomes appreciably reduced after replacing batteries.

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  • What are the different operating modes available on the Fujitsu AST7 SERIES Air Conditioner?

    The Fujitsu AST7 SERIES Air Conditioner offers the following operating modes:

    • AUTO (Automatic Operation)
    • COOL
    • DRY
    • HEAT (for Heat & Cool models only)
    • FAN

    For more information, see page 7 of the manual.
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  • Why is the green light blinking on my Fujitsu AST7 SERIES Air Conditioner?

    If the TIMER indicator lamp (green) flashes when the timer is operating, it indicates that a fault has occurred with the timer setting.

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  • How to set the timer on the Fujitsu AST7 SERIES Air Conditioner?

    To set the timer, first ensure the remote control unit is set to the correct current time. Then, follow these steps:

    1. Press the START/STOP button on the remote control. If the unit is already operating, proceed to the next step.
    2. Press the TIMER button to select either the OFF timer or ON timer operation. Each press changes the timer function in the order: RESET → OFF → ON → PROGRAM (OFF → ON, OFF ← ON). The indoor unit's TIMER indicator lamp (green) will light.
    3. Use the SET TIME buttons to adjust the desired OFF time or ON time. Press the '+' button to advance the time or the '-' button to reverse the time. The time display will flash for about five seconds while adjusting. After about five seconds, the display will reappear.

    To use the PROGRAM timer, which allows for a sequence of OFF and ON timer operations within a 24-hour period:

    1. Press the START/STOP button. If the unit is already operating, proceed to the next step.
    2. Set the desired times for both OFF timer and ON timer using the steps above. The indoor unit's TIMER indicator lamp (green) will light.
    3. Press the TIMER button to select the PROGRAM timer operation (either OFF → ON or OFF ← ON). The display will alternately show "OFF timer" and "ON timer", then change to show the time setting for the operation to occur first. The PROGRAM timer will begin operation, and if the ON timer was selected to operate first, the unit will stop operating at this point. After about five seconds, the entire display will reappear.

    For more information, see page 10 of the manual.
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  • Why is the operation light blinking on my Fujitsu AST7 SERIES Air Conditioner?

    The OPERATION indicator lamp (red) will flash slowly during the defrosting operation. It will flash quickly (1 second on, 1 second off) when the selected operating mode cannot be used.

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  • How to adjust the fan speed settings on the Fujitsu AST7 SERIES Air Conditioner?

    To set the fan speed, press the FAN CONTROL button on the remote control. Each time the button is pressed, the fan speed changes in the following order: AUTO → HIGH → MED → LOW → QUIET. The display will reappear about three seconds later.

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  • How do I turn on my Fujitsu AST7 SERIES Air Conditioner?

    To turn on your air conditioner, press the START/STOP button on the remote control. The indoor unit's OPERATION indicator lamp (red) will light, indicating that the air conditioner has started operating.

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  • Why is the timer light flashing on my Fujitsu AST7 SERIES Air Conditioner?

    If the TIMER indicator lamp (green) flashes when the timer is operating, it indicates that a fault has occurred with the timer setting.

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  • How do I use the control panel on my Fujitsu AST7 SERIES Air Conditioner?

    The control panel on the main unit is primarily used for MANUAL AUTO operation when the remote control is unavailable. To use it, press the MANUAL AUTO button, which is located inside the intake grille. Pressing it again will stop the operation. When operating via the main unit, the air conditioner functions in the same way as the AUTO mode selected on the remote control unit, with the fan speed set to "AUTO" and a standard thermostat setting.

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  • How do I turn on my Fujitsu AST7 SERIES Air Conditioner without the remote?

    You can use the main unit controls for manual auto operation in the event the remote control unit is lost or unavailable. Press the MANUAL AUTO button on the main unit control panel. The controls are located inside the intake grille. To stop operation, press the MANUAL AUTO button once again. When operated this way, the unit will operate under the same mode as the AUTO mode selected on the remote control unit, with the fan speed set to "AUTO" and the thermostat setting as standard.

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  • How to remove the cover of the Fujitsu AST7 SERIES Air Conditioner?

    To remove the intake grille (cover):

    1. Place your fingers at both lower ends of the grille panel and lift it forward. If the grille seems to catch partway, continue lifting upward to remove.
    2. Pull past the intermediate catch and open the Intake Grille wide so that it becomes horizontal.
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  • How to turn off the Fujitsu AST7 SERIES Air Conditioner?

    To stop operation, press the START/STOP button. The OPERATION indicator lamp (red) will go out.

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  • What common noises can I expect from my Fujitsu AST7 SERIES Air Conditioner during normal operation?

    During normal operation, you might hear the following noises:

    • Sound of water flowing in the air conditioner's piping, especially for about 2 to 3 minutes after starting operation.
    • A slight squeaking sound due to minute expansion and contraction of the front cover from temperature changes.
    • A sizzling sound during Heating operation, which is produced by the Automatic Defrosting operation.

    For more information, see page 17 of the manual.
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Summarization of Contents

Safety Precautions
Features and Functions
Automatic Operation
Explains how the unit automatically selects operating modes based on room conditions.
Sleep Timer
Details the timer function that gradually adjusts settings for comfort during sleep.
Wireless Remote Control Unit
Highlights the convenience and features of the remote control unit.
Swing Operation
Describes the automatic up/down movement of louvers for air distribution.
Removable Intake Grille
Notes the easy access for cleaning the indoor unit's intake grille.
Mildew-Resistant Filter
Mentions the air filter's treatment to resist mildew growth for cleaner use.
Super Quiet Operation
Explains the mode that reduces airflow for quieter operation.
Air Cleaning Filter
Describes the filter that uses an electrostatic principle to clean the air.
Name of Parts
Preparation
To Use the Remote Control Unit
Instructions on aiming the remote control, its operating range, and signal reception.
Operation
To Select Mode Operation
Guide on choosing operating modes like AUTO, COOL, DRY, HEAT, and FAN.
To Set the Thermostat
Instructions for adjusting the desired room temperature settings.
To Set the Fan Speed
How to adjust fan speed among AUTO, HIGH, MED, LOW, and QUIET settings.
About Mode Operation
Explanation of AUTO mode functionality and unit monitoring.
Auto: Cooling Model
Details automatic mode selection for the Cooling Model based on room temperature.
Timer Operation
To Use the ON Timer or OFF Timer
Steps to set timers for turning the air conditioner on or off.
To Use the Program Timer
How to set a sequence of ON and OFF timer operations.
Sleep Timer Operation
To Use the Sleep Timer
Instructions for activating the sleep timer function to stop operation.
About the Sleep Timer
Explains how the sleep timer modifies settings for comfort during sleep.
Adjusting the Direction of Air Circulation
Vertical Air Direction Adjustment
How to adjust the up/down airflow direction using the remote control.
Right-Left Adjustment
Instructions for manually adjusting the side-to-side airflow direction.
Swing Operation
About Swing Operation
Details on how the swing function operates and any limitations.
Manual Auto Operation
How To Use the Main Unit Controls
Guide to operating the unit directly from the main control panel.
Cleaning and Care
Cleaning the Intake Grille
Steps for removing and cleaning the main intake grille of the indoor unit.
Cleaning the Air Filter
Instructions for cleaning the unit's air filters.
Air Cleaning Filter Installation
Procedure for installing the air cleaning filters into the unit.
Replacing Dirty Air Cleaning Filters
Guidance on replacing used air cleaning filters with new ones.
Maintenance of Deodorizing Filters
How to clean and maintain the deodorizing filters to preserve effectiveness.
Troubleshooting
Operating Tips
Operation and Performance
General notes on how the unit performs under various conditions.
Microcomputer-controlled Automatic Defrosting
Explanation of the automatic defrost cycle during heating operation.
Auto Restart
How the unit automatically resumes operation after a power interruption.
Multi-type Air Conditioner
Information regarding connecting the unit to a multi-type outdoor system.
Simultaneous Use of Multiple Units
Guidelines for operating multiple indoor units concurrently.
Temperature and Humidity Range
Permissible operating ranges for indoor and outdoor temperature and humidity.

Table of Contents