ASTG18LUCA / AOTG18LUC
Applies to
| Indoor unit | ASTG18LUCA |
| Outdoor unit | AOTG18LUC |
| Refrigerant | R410A |
| Manual | 9319356020 |
1. Basic operation
Start the air conditioner
- Press the START/STOP button on the wireless remote controller.
- Press MODE to select the required operating mode.
- Use the TEMP. buttons to adjust the temperature.
- Press FAN to select the fan speed.
| Setting | Options / Range |
|---|---|
| Operating modes | AUTO, COOL, DRY, HEAT, FAN |
| AUTO temperature | 18–30°C |
| Cooling / Dry temperature | 18–30°C |
| Heating temperature | 16–30°C |
| Fan speeds | AUTO, HIGH, MED, LOW, QUIET |
AUTO mode
When AUTO is selected, the unit assesses room and outdoor conditions and automatically selects cooling, dry, heating or monitor operation to maintain the set temperature.
Super Quiet
Select QUIET with the FAN button to reduce indoor airflow and operating sound. Heating and cooling performance may be reduced while Super Quiet operation is active.
2. Timer operation
Set the day of the week and current time before using timer functions.
| Timer | What it does |
|---|---|
| ON Timer | Starts the air conditioner at the selected time. |
| OFF Timer | Stops the air conditioner at the selected time. |
| Program Timer | Combines one ON and one OFF timer transition within a 24-hour period. |
| Sleep Timer | Adjusts temperature progressively for sleeping comfort, then stops the unit after the selected period. |
| Weekly Timer | Allows up to four ON/OFF reservations per day and up to 28 reservations per week, including temperature settings for ON events. |
3. Useful functions
Human Sensor – Energy Saving
The Human Sensor can automatically reduce operating power when no movement is detected in the room for approximately 20 minutes. When someone returns, the unit automatically returns to the original settings.
| Mode | Energy Saving response when room is unoccupied |
|---|---|
| Cooling / Dry | Set temperature increases by up to approximately 2°C. |
| Heating | Set temperature decreases by up to approximately 4°C. |
| AUTO | Energy Saving follows the automatically selected operating mode. |
Press the SENSOR button to enable or disable Energy Saving. The sensor detects movement using infrared and may not detect a stationary person or a person obscured by furniture.
Powerful operation
Press POWERFUL to operate the system at maximum output for rapid cooling or heating. Powerful operation normally ends automatically when the set temperature is reached or after approximately 20 minutes.
Economy operation
Press ECONOMY during normal operation to reduce energy use. At maximum output, Economy operation is approximately 70% of normal output for cooling and heating.
10°C Heat
Press the 10°C HEAT button to help prevent the room temperature from falling too far. To stop 10°C Heat operation, press START/STOP.
Outdoor Unit Low Noise
Press OUTDOOR UNIT LOW NOISE to reduce outdoor unit sound by limiting fan speed and compressor speed. This function is available during cooling, heating and AUTO operation, but not FAN or DRY.
The Low Noise setting is retained after the air conditioner is stopped. Under high outdoor temperatures, or when compressor and fan speeds are already sufficiently low, the function may have little or no additional effect.
Swing operation
Press SWING to move the vertical airflow louvers automatically. During cooling/dry operation the swing range is positions 1–4; during heating it is positions 4–7.
Manual Auto operation
If the wireless remote controller is unavailable, press the indoor unit MANUAL AUTO button for more than three seconds and less than ten seconds. The unit will operate in AUTO mode, with AUTO fan speed and a standard setting of 24°C.
4. Airflow direction
- Use the remote controller SET button for vertical airflow direction.
- Cooling/Dry: recommended positions 1, 2 or 3.
- Heating: recommended positions 4, 5, 6 or 7.
- Horizontal right-left airflow is adjusted manually after the vertical louvers have stopped completely.
5. Cleaning and care
- Stop the air conditioner and switch off the electrical breaker.
- Open the intake grille and secure it using the grille stay.
- Remove the air filters.
- Remove dust with a vacuum cleaner, or wash using neutral detergent and warm water.
- Allow washed filters to dry thoroughly in a shaded location.
- Refit the filters and close the intake grille completely.
Under normal use, the air filters should be cleaned approximately every two weeks.
Air cleaning filters
| Filter | Part / Maintenance |
|---|---|
| Polyphenol Catechin Air Cleaning Filter | UTR-FA16 – disposable; generally replace approximately every 3 months. |
| Negative Air Ions Deodorizing Filter | UTR-FA16-2 – clean approximately every 3 months; generally replace approximately every 3 years. |
6. Troubleshooting
| Symptom | Check / Explanation |
|---|---|
| Does not start immediately | A protection delay of about three minutes may occur after stopping/restarting the unit or restoring power. |
| Does not operate | Check the breaker, power supply, timer settings and that the intake grille is completely closed. |
| Weak airflow in heating | The fan may operate at very low speed while the indoor unit warms up, or when room temperature is above the set temperature. |
| Heating stops temporarily | Automatic defrost may interrupt heating for up to approximately 15 minutes. The OPERATION indicator flashes during defrost. |
| Water from outdoor unit in heating | This can occur during automatic defrost operation and is normal. |
| Poor cooling or heating | Check the air filter, intake/outlet obstruction, temperature setting, open doors/windows, direct sunlight, OUTDOOR UNIT LOW NOISE and SUPER QUIET settings. |
| Remote control response differs | Check that the remote controller batteries are correctly installed and are not flat. |
7. Operating limits and notes
| Operation | Permissible range |
|---|---|
| Cooling / Dry – outdoor | Approximately 10°C to 46°C |
| Cooling / Dry – indoor | Approximately 18°C to 32°C; indoor humidity below approximately 80% |
| Heating – outdoor | Approximately -15°C to 24°C |
| Heating – indoor | Approximately 16°C to 30°C |
- Heating performance reduces as outdoor air temperature falls.
- Automatic defrost may occur during heating in low outdoor temperature and high humidity conditions.
- After a power interruption, the air conditioner automatically restarts in its previous operating mode when power is restored.
- If a power interruption occurs during timer operation, the timer may require resetting.