Brand: MITSUBISHI ELECTRIC
Category: Air Conditioner
Document Type: Manual
Language: EN
Available Languages: EN , ES
Manual for MSZ-FS12NA
Uploaded: Nov. 21, 2025, 6:20 p.m.
Warranty Information
The warranty period is 24 months. Regular maintenance is essential for system performance.
Basic Operation
This manual covers the operation, installation, and troubleshooting of the MITSUBISHI ELECTRIC MSZ-FS12NA split-type air conditioner.
Key Operations:
- Modes: AUTO, COOL, DRY, HEAT, FAN. AUTO mode automatically selects the best mode based on room temperature.
- I-SEE OPERATION: Senses room occupancy for energy saving and can adjust airflow direction (INDIRECT/DIRECT mode).
- Remote Controller: Used for all operations, including setting temperature, fan speed, airflow direction, timers, and special functions like SMART SET and ECONO COOL.
- Timers: ON/OFF Timer and Weekly Timer allow for scheduled operation.
- Cleaning: Regular cleaning of air filters (every 2 weeks) is recommended for optimal performance.
Troubleshooting and error codes
| Symptom | Explanation & Check points |
|---|---|
| Indoor Unit | |
| The unit cannot be operated. | Is the breaker turned on? Is the power supply plug connected? Is the ON timer set? |
| The horizontal vane does not move. | Are the horizontal and vertical vanes installed correctly? Is the fan guard deformed? When the breaker is turned on, the horizontal vanes' position will be reset in about a minute. |
| Mist is discharged from the air outlet of the indoor unit. | The cool air from the unit rapidly cools moisture in the air inside the room, and it turns into mist. |
| Outdoor Unit | |
| Water leaks from the outdoor unit. | During COOL and DRY operations, pipe or pipe connecting sections are cooled and this causes water to condense. In the heating operation, water condensed on the heat exchanger drips down. |
| Remote controller | |
| The display on the remote controller does not appear or it is dim. The indoor unit does not respond to the remote control signal. | Are the batteries exhausted? Is the polarity (+, -) of the batteries correct? |
| Does not cool or heat | |
| The room cannot be cooled or heated sufficiently. | Is the temperature setting appropriate? Is the fan setting appropriate? Are the filters clean? Are there any obstacles blocking the air inlet or outlet? |
| Air does not blow out soon in the heating operation. | Please wait as the unit is preparing to blow out warm air. |
| Sound | |
| Cracking sound is heard. | This sound is generated by the expansion/contraction of the front panel, etc. due to change in temperature. |
| The sound of water flowing is heard. | This is the sound of refrigerant or condensed water flowing in the unit. |
| Timer | |
| Weekly timer does not operate according to settings. | Transmit the setting information of the weekly timer to the indoor unit again. Ensure information is successfully received. The indoor unit built-in clock will be incorrect after a power failure. |