Brand: Emerson
Category: Air Conditioner
Document Type: Manual
Language: EN
Available Languages: ES , EN
Manual for IST3
Uploaded: April 20, 2026, 7:59 p.m.
Warranty Information
No warranty period is specified in this manual.
COOL Mode: Indoor temp: 17°C - 32°C (62°F - 90°F). Outdoor temp: 0°C - 50°C (32°F - 122°F).
HEAT Mode: Indoor temp: 0°C - 30°C (32°F - 86°F). Outdoor temp: -15°C - 30°C (5°F - 76°F).
DRY Mode: Indoor temp: 17°C - 32°C (62°F - 90°F). Outdoor temp: 0°C - 50°C (32°F - 122°F).
Troubleshooting and error codes
| Problem | Possible Causes | Solution |
| Unit does not function | Power failure | Wait for the power supply to be restored |
| Power switch is turned OFF | Turn on the power supply | |
| Fuse is blown | Replace the fuse | |
| Remote control batteries are dead | Replace the remote control batteries | |
| The unit's 3-minute protection has been activated | Wait 3 minutes before restarting the unit | |
| Poor cooling performance | The temperature setting may be higher than the ambient temperature | Lower the temperature setting |
| The heat exchanger of the indoor or outdoor unit is dirty | Clean the affected heat exchanger | |
| The air filter is dirty | Remove and clean the filter according to instructions | |
| The air inlet or outlet of any of the units is blocked | Turn off the unit, remove the obstruction, and turn it back on | |
| Doors and windows are open | Ensure all doors and windows are closed while the unit is operating. | |
| Excessive heat is generated by sunlight | Close windows and curtains during periods of high heat or bright sun. | |
| Low refrigerant due to leaks or prolonged use | Check for leaks, reseal if necessary, and recharge the unit with refrigerant. | |
| Unit turns on and off frequently | Too much or too little refrigerant in the system | Check for leaks and recharge the system with refrigerant. |
| Presence of air, incompressible gas or foreign material in the refrigeration system | Evacuate and recharge the system with refrigerant | |
| System circuit is blocked | Identify the blocked circuit and replace the faulty equipment | |
| Compressor is faulty | Replace the compressor | |
| Voltage is too high or too low | Install a pressure switch to regulate voltage | |
| Poor heating performance | Outdoor temperature is below 7°C (44.5°F) | Check for leaks and recharge the system with refrigerant. |
| Cold air enters through doors and windows | Ensure all doors and windows are closed during use | |
| Low refrigerant due to leaks or prolonged use | Check for leaks, reseal if necessary, and remove the refrigerant. |