What is Auto Restart Mini Split: A Comprehensive Guide

Auto restart is a crucial feature in mini-split air conditioning systems that automatically restarts the unit to its previous settings following a temporary power failure. This feature is particularly beneficial in areas prone to power outages, as it eliminates the need for manual reprogramming of the unit’s settings.

Understanding the Auto Restart Feature

When the power is turned off and back on during use, the auto restart feature will automatically restart the unit with its previous settings. To deactivate or cancel the auto restart feature, you need to press and hold the start/stop button on the main unit for more than 8 seconds.

In the event of a temporary power failure, the air conditioner will automatically restart in the same operating mode as before, once power has been restored. This feature is available in various mini-split systems, including the Mitsubishi mini split and the Fujitsu General AIRSTAGE SINGLE-ROOM MINI-SPLIT SYSTEMS.

Benefits of the Auto Restart Feature

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The auto restart feature is particularly useful for those who want to ensure that their air conditioning system is always operating at the desired settings, without the need for manual intervention. This feature is especially important for those who may not be present when a power outage occurs, as it ensures that the system will automatically return to its previous settings once power is restored.

Technical Specifications and Functionality

The auto restart feature in mini-split air conditioning systems is designed to work seamlessly with the unit’s internal microprocessor and control system. When a power outage occurs, the microprocessor stores the current settings, including the temperature, fan speed, and mode of operation. Once power is restored, the microprocessor retrieves these stored settings and automatically restarts the unit, ensuring that the system resumes operation with the same settings as before the power failure.

To ensure the reliability and efficiency of the auto restart feature, mini-split manufacturers often incorporate advanced circuitry and failsafe mechanisms. This includes the use of non-volatile memory (NVM) or battery-backed memory to store the settings, as well as robust power supply designs that can withstand brief power interruptions without causing the system to reset or malfunction.

Installation and Configuration

The auto restart feature is typically pre-configured and enabled by default in most mini-split systems. However, in some cases, you may need to manually enable or configure the feature during the installation or setup process. Refer to the manufacturer’s instructions or consult with a qualified HVAC technician for specific guidance on how to enable or disable the auto restart feature on your mini-split system.

Troubleshooting and Maintenance

If you encounter any issues with the auto restart feature, such as the unit not restarting automatically after a power outage, there are a few troubleshooting steps you can take:

  1. Check the power supply: Ensure that the power supply to the mini-split system is stable and not experiencing frequent or prolonged interruptions.
  2. Inspect the electrical connections: Verify that all electrical connections, including the power cord and wiring, are secure and free from damage.
  3. Reset the system: Try resetting the mini-split system by turning it off and then back on, or by pressing the start/stop button for more than 8 seconds to deactivate and then reactivate the auto restart feature.
  4. Consult the manufacturer: If the issue persists, refer to the manufacturer’s troubleshooting guide or contact their customer support for further assistance.

Regular maintenance of the mini-split system, such as cleaning the air filters and outdoor unit, can also help ensure the proper functioning of the auto restart feature and the overall efficiency of the system.


The auto restart feature in mini-split air conditioning systems is a valuable asset that can provide peace of mind and convenience for homeowners and building occupants. By automatically restoring the system to its previous settings after a power outage, this feature eliminates the need for manual intervention and ensures that the air conditioning system continues to operate at the desired settings, even in the event of unexpected power interruptions.

Whether you’re considering a new mini-split installation or troubleshooting an existing system, understanding the auto restart feature and its technical specifications can help you make informed decisions and maintain the optimal performance of your air conditioning system.