Fujitsu AST12LSACW - User Manual

Questions and Answers:

M
Mark PerkinsAug 12, 2025
What to do if my Fujitsu AST12LSACW Air Conditioner has poor cooling performance?
- C
  charlesbryantAug 13, 2025
  If your Fujitsu Air Conditioner isn't cooling well, several factors could be the cause. First, check if the air filter is dirty and clean it if necessary. Make sure that the air conditioner's intake grille or outlet port isn't blocked. Ensure that you've correctly adjusted the thermostat settings. Also, check for open windows or doors, and close them. If it's during cooling operation and sunlight is entering the room, close the curtains. Consider if there are heat-generating appliances or too many people in the room. Finally, check if the unit is set to SUPER QUIET operation, as this can reduce cooling performance.
A
Amanda GambleAug 16, 2025
What to do if my Fujitsu Air Conditioner doesn't operate at all?
- B
  Brandon NelsonAug 16, 2025
  If your Fujitsu Air Conditioner isn't operating, start by checking if the power supply plug is properly connected to the outlet. Also, verify whether there has been a power failure. Finally, check if a fuse has blown out or a circuit breaker has been tripped.
R
Robert ValdezAug 20, 2025
Why does my Fujitsu Air Conditioner airflow become weak or stop?
- A
  aterryAug 20, 2025
  There are several reasons why the airflow in your Fujitsu Air Conditioner might weaken or stop. When heating operation is started, fan speed is temporarily very low, to allow internal parts to warm up. During heating operation, if the room temperature rises above the thermostat setting, the outdoor unit will stop, and the indoor unit will operate at very low fan speed. During heating operation, the unit will temporarily stop operation (between 7 and 15 minutes) as the Automatic Defrosting mode operates. The fan may operate at very low speed during Dry operation or when the unit is monitoring the room’s temperature. During SUPER QUIET operation, the fan will operate at very low speed. Also, in the monitor AUTO operation, the fan will operate at very low speed.
K
Kevin McintoshAug 25, 2025
Why is water produced from the outdoor unit of my Fujitsu Air Conditioner?
- W
  wolfepatrickAug 25, 2025
  During heating operation, water may be produced from the outdoor unit of your Fujitsu Air Conditioner due to the automatic defrosting operation.
T
Tammy DouglasAug 28, 2025
Why does my Fujitsu Air Conditioner smell?
- J
  Joshua CollinsAug 28, 2025
  A smell may be emitted from your Fujitsu Air Conditioner's indoor unit because room odors (from furniture, tobacco, etc.) have been drawn into the unit.
M
Mr. Shawn Stanley MDAug 31, 2025
Why does my Fujitsu AST12LSACW not operate immediately?
- A
  Alicia SantanaAug 31, 2025
  If your Fujitsu Air Conditioner is stopped and then immediately started again, the compressor will not operate for about 3 minutes to prevent fuse blowouts. Also, whenever the Power Supply Plug is disconnected and then re-connected to a power outlet, the protection circuit will operate for about 3 minutes, preventing unit operation during that period.
V
vanessabowenSep 4, 2025
Why does my Fujitsu AST12LSACW emit mist or steam?
- E
  Eric BowersSep 4, 2025
  During cooling or dry operation, a thin mist may be seen emitted from the indoor unit of your Fujitsu Air Conditioner. This results from the sudden cooling of room air by the air emitted from the air conditioner, leading to condensation and misting. During heating operation, the outdoor unit’s fan may stop, and steam may be seen rising from the unit due to automatic defrosting operation.
D
Diana WaltonSep 8, 2025
Why does my Fujitsu Air Conditioner make noise?
- K
  Kevin JohnsonSep 8, 2025
  During operation and immediately after stopping the unit, the sound of water flowing in the air conditioner’s piping may be heard. Also, noise may be particularly noticeable for about 2 to 3 minutes after starting operation (sound of coolant flowing). During Heating operation, a sizzling sound may be heard occasionally which is produced by the Automatic Defrosting operation.

Fujitsu AST12LSACW Specifications

General

Cooling Capacity	3.5 kW
Heating Capacity	4.0 kW
Power Supply	220-240V, 50Hz
Type	Split System
Noise Level (Outdoor)	50 dB

Summary

Safety Precautions

Features and Functions

Inverter

Provides powerful initial operation and economical low-power subsequent operation for desired temperature.

Coil Dry Operation

Dries the indoor unit to prevent mold and restrain bacteria growth.

Auto Changeover

Automatically switches between cooling, dry, and heating modes to maintain set temperature.

Sleep Timer

Gradually adjusts thermostat settings during sleep for comfort and automatic shut-off.

Wireless Remote Control Unit

Allows convenient control of the air conditioner's operation.

Swing Operation

Automatically swings louvers up and down for even air distribution in the room.

Removable Open Panel

Allows easy cleaning and maintenance of the indoor unit's panel.

Mildew-Resistant Filter

Air filter treated to resist mildew growth for cleaner use and easier care.

Super Quiet Operation

Reduces airflow for quieter operation when the QUIET setting is selected.

Air Cleaning Filter (Optional)

Optional filter uses electrostatic principle to clean air of fine particulate matter.

Name of Parts

Preparation

Turn on the Power

Instructions for connecting the power supply plug or circuit breaker.

Load Batteries

Steps for inserting batteries into the remote control unit.

To Use the Remote Control Unit

Guidelines for operating the remote control unit and its signal reception.

Operation

To Select Mode Operation

Steps to start the unit and select the operating mode (AUTO, COOL, DRY, HEAT, FAN).

To Set the Thermostat

Instructions for adjusting the desired temperature setting using the SET TEMP. button.

To Set the Fan Speed

How to change the fan speed settings (AUTO, HIGH, MED, LOW, QUIET).

To Stop Operation

Procedure to stop the air conditioner operation.

About AUTO CHANGEOVER Operation

Explanation of how the unit automatically selects operating modes based on room conditions.

About Mode Operation

Details on Heating, Cooling, Dry, and Fan modes, including specific operational notes.

Timer Operation

To Use the OFF TIMER

Instructions for setting the timer to turn the unit off at a specified time.

To Use the ON TIMER

Instructions for setting the timer to turn the unit on at a specified time.

Sleep Timer Operation

To Use the SLEEP timer

How to set the sleep timer to automatically adjust temperature and turn off the unit.

To Change the Timer Settings

Procedure to modify existing timer settings.

About the SLEEP timer

Explanation of how the sleep timer adjusts temperature settings for comfort during sleep.

Confirmation of TIMERs time

How to check the set timer time on the remote control display.

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

How to manually adjust the left-right airflow direction using the louvers.

Swing Operation

Coil Dry Operation

Manual Auto Operation

How To Use the Main Unit Controls

Instructions for operating the unit using the main unit's controls when the remote is unavailable.

Cleaning and Care

Cleaning the Open Panel

Step-by-step guide to remove and clean the indoor unit's open panel.

Cleaning the Air Filter

Instructions for cleaning the air filter, including removal, cleaning methods, and replacement.

Troubleshooting

Operating Tips

Operation and Performance

Information on heating performance and microcomputer-controlled automatic defrosting.

AUTO Restart

How the unit restarts automatically after a power interruption.

Temperature and Humidity Range

Recommended operating ranges for outdoor and indoor temperatures for different modes.

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Fujitsu AST12LSACW - User Manual

Table of Contents

Questions and Answers:

Fujitsu AST12LSACW Specifications

Summary

Safety Precautions

Features and Functions

Inverter

Coil Dry Operation

Auto Changeover

Sleep Timer

Wireless Remote Control Unit

Swing Operation

Removable Open Panel

Mildew-Resistant Filter

Super Quiet Operation

Air Cleaning Filter (Optional)

Name of Parts

Preparation

Turn on the Power

Load Batteries

To Use the Remote Control Unit

Operation

To Select Mode Operation

To Set the Thermostat

To Set the Fan Speed

To Stop Operation

About AUTO CHANGEOVER Operation

About Mode Operation

Timer Operation

To Use the OFF TIMER

To Use the ON TIMER

Sleep Timer Operation

To Use the SLEEP timer

To Change the Timer Settings

About the SLEEP timer

Confirmation of TIMERs time

Adjusting the Direction of Air Circulation

Vertical Air Direction Adjustment

Right-Left Adjustment

Swing Operation

Coil Dry Operation

Manual Auto Operation

How To Use the Main Unit Controls

Cleaning and Care

Cleaning the Open Panel

Cleaning the Air Filter

Troubleshooting

Operating Tips

Operation and Performance

AUTO Restart

Temperature and Humidity Range

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