Unlock Your Fujitsu Thermostat: A Comprehensive Guide

Unlocking a Fujitsu thermostat is a crucial step in ensuring your air conditioning unit operates efficiently and effectively. By enabling the “switching function of the room temperature sensor,” you can unlock your Fujitsu thermostat and allow it to work seamlessly with the Airzone Eco-Adapt algorithm. This comprehensive guide will walk you through the step-by-step process to unlock your Fujitsu thermostat, providing you with the technical details and expert-level insights to ensure a successful DIY experience.

Preparing for the Unlock Process

Before you begin the unlock process, it’s essential to gather the necessary tools and information. Ensure that you have the following items on hand:

  1. Your Fujitsu thermostat model number and user manual.
  2. A small, flat-head screwdriver or a similar tool to access the DS1 microswitch.
  3. A pen and paper to record any settings or configurations you may need to reference later.

It’s also important to note that the specific steps to unlock a Fujitsu thermostat may vary depending on the model and year of the unit. Therefore, it’s recommended to consult your user manual or contact Fujitsu’s customer support for model-specific instructions.

Unlocking the Fujitsu Thermostat

how to unlock a Fujitsu thermostatImage source: Fujitsu AC by Dinkun Chen

  1. Accessing the Settings Menu:
  2. Press and hold the “ECONOMY” button on your Fujitsu thermostat until a key icon appears on the screen.
  3. If your AC unit does not have this parameter configured, proceed to the next step.
  4. Access the settings menu by pressing the “SET TEMP” and “FAN” buttons simultaneously.

  5. Enabling the Switching Function of the Room Temperature Sensor:

  6. Navigate to position 42 on the menu, which is the “switching function of the room temperature sensor.”
  7. Set this parameter to 01 using the “SET TEMP” buttons.

  8. Saving the New Settings:

  9. Press and hold the “TIMER SET” button until the values on the display stop flashing, indicating that the new settings have been saved.

  10. Configuring the Temperature Sensor:

  11. Change menu function number 48 to position 01 to use the temperature sensor on your AC unit’s remote controller.
  12. Save the configuration by following the same steps as in the previous step.

  13. Resetting the Indoor Unit:

  14. Switch off the indoor unit’s power and switch it on again.
  15. Press the “ECONOMY” button again, and the icon that corresponds to the function will appear, confirming that the change has been made.

  16. Preventing Configuration Loss:

  17. Open your Fujitsu thermostat and locate the DS1 microswitch.
  18. Set PIN number 6 in the ON position to ensure that the configuration is not lost.

Troubleshooting and Additional Considerations

If you encounter any issues during the unlock process, consider the following troubleshooting steps:

  1. Verify Model-Specific Instructions: Refer to your Fujitsu thermostat’s user manual or contact Fujitsu’s customer support to ensure that you are following the correct steps for your specific model.
  2. Check Power Supply: Ensure that the indoor unit is receiving power and that the power supply is not interrupted during the unlock process.
  3. Confirm Microswitch Configuration: Double-check that the DS1 microswitch is properly set to the ON position for PIN number 6 to prevent configuration loss.

Additionally, it’s important to note that the Airzone Eco-Adapt algorithm is designed to optimize the performance of your Fujitsu AC unit. By unlocking the thermostat and enabling the “switching function of the room temperature sensor,” you are allowing the algorithm to work as intended, ensuring efficient and effective cooling or heating in your home or office.


Unlocking your Fujitsu thermostat is a straightforward process that can significantly improve the performance of your air conditioning unit. By following the step-by-step instructions outlined in this comprehensive guide, you can unlock your Fujitsu thermostat and enable the Airzone Eco-Adapt algorithm to work seamlessly with your system. Remember to consult your user manual or contact Fujitsu’s customer support for any model-specific instructions, and always prioritize safety when working with electrical components.


  1. Fujitsu General Limited’s Support Page
  2. YouTube Video: Configuring Fujitsu AC Unit for Airzone Eco-Adapt
  3. Fujitsu General Global’s Operating Manual for Thermostat Sensors