Mitsubishi Electric Air Conditioner Blinking Green Light

Mitsubishi Electric air conditioners are renowned for their reliability and efficiency. However, if you encounter a blinking green light on your Mitsubishi Electric air conditioner, it could indicate a problem that needs attention. In this guide, we’ll delve into the possible causes of a blinking green light on your Mitsubishi Electric air conditioner and provide steps to troubleshoot and resolve the issue.

Understanding the Blinking Green Light


Now that we’ve identified potential causes, here are the steps you can take to troubleshoot a Mitsubishi Electric air conditioner with a blinking green light:

  1. Check Power Supply:
    • Ensure the air conditioner is properly plugged in and the power source is functioning. Reset the circuit breaker or replace any blown fuses if necessary.
  2. Adjust Thermostat Settings:
    • Verify that the thermostat settings are suitable for the room’s temperature and your comfort preferences.
  3. Inspect the Air Filter:
    • Remove and clean or replace the air filter if it’s dirty or clogged. This simple maintenance task can often resolve performance issues.
  4. Clear Condensation Drain:
    • Examine the condensation drain for blockages. Clean it out if needed to allow proper drainage.
  5. Professional Inspection:
    • If you suspect refrigerant issues, sensor problems, or communication errors, it’s advisable to contact a Mitsubishi Electric certified technician. They have the expertise and tools to diagnose and repair complex issues.

Regular Maintenance and Preventive Measures

Preventive maintenance is essential to keep your Mitsubishi Electric air conditioner in optimal working condition and reduce the likelihood of a blinking green light. Here are some additional steps you can take:

  1. Regular Cleaning:
    • Clean the indoor and outdoor units periodically to remove dust and debris. This helps maintain efficient airflow and prevents the buildup of contaminants that can affect system performance.
  2. Coil Cleaning:
    • Over time, the coils in the indoor and outdoor units can become dirty or frost-covered, leading to reduced efficiency and potential blinking green light issues. Follow the manufacturer’s guidelines to clean the coils properly.
  3. Check for Refrigerant Leaks:
    • Keep an eye out for any signs of refrigerant leaks, such as hissing sounds or ice buildup on the outdoor unit. If you suspect a leak, contact a professional technician immediately.
  4. Inspect Wiring and Connections:
    • Periodically inspect the wiring and connections between the indoor and outdoor units. Loose or damaged wires can lead to communication errors and other operational problems.
  5. Replace Batteries in Remote Control:
    • If your Mitsubishi Electric air conditioner comes with a remote control, replace the batteries regularly to ensure it functions correctly and communicates effectively with the indoor unit.

Dealing with Specific Error Codes

Mitsubishi Electric air conditioners often come equipped with error code displays. If you see a blinking green light accompanied by a specific error code on the display, refer to your user manual or the manufacturer’s website for a list of error codes and their meanings. These codes can provide valuable information about the nature of the problem, making troubleshooting more targeted.

Professional Servicing

While many issues can be resolved through DIY troubleshooting and maintenance, it’s important to recognize when it’s time to call in a professional technician. Here are some scenarios where professional servicing is highly recommended:

  1. Complex Technical Issues:
    • If you’re unable to identify the cause of the blinking green light or if the problem persists after basic troubleshooting, it’s best to consult a Mitsubishi Electric authorized technician. They have the training and diagnostic tools to pinpoint and resolve complex technical issues.
  2. Warranty Considerations:
    • If your air conditioner is still under warranty, attempting extensive DIY repairs can void the warranty. Professional servicing ensures that repairs are performed according to manufacturer specifications and won’t impact your warranty coverage.
  3. Refrigerant Handling:
    • Handling refrigerant requires specialized equipment and knowledge. If you suspect a refrigerant-related issue, leave it to a certified technician to handle, as they are trained in safe refrigerant management.

Troubleshooting Steps

No.IssuePossible SolutionAdditional StepsResult
1Blinking green light persistsCheck power source connectionsInspect remote control batteriesLight remains blinking
2Unit not coolingClean or replace air filtersVerify thermostat settingsNo change in cooling
3Blinking light after power outageWait for a few minutes, then restartCheck circuit breaker or fuseLight continues to blink
4Unit emitting warm airEnsure outdoor unit is unobstructedConfirm if fan is runningAir remains warm
5Flashing light with strange noisesSchedule professional inspectionNote any unusual soundsNo change in light or noise
6Inconsistent airflowClean evaporator and condenser coilsCheck air ducts for blockageAirflow issues persist
7Unit turns off shortly after startingInspect for clogged drain lineReset thermostat settingsProblem persists
8Blinking light and freezing upEnsure proper refrigerant levelsMonitor for ice buildup on coilsIssue remains unresolved
9Remote control not functioningReplace remote batteriesReprogram remote if necessaryRemote still not working
10Unit produces unpleasant odorsClean or replace air filtersCheck for mold or mildew in unitOdor problem continues

Blinking Light Patterns

Blinking PatternMeaning
Steady blinkNormal operation or idle state
Slow blink (1 Hz)Unit is in defrost cycle
Fast blink (5 Hz)Communication error with remote
2 blinks, pauseIndoor fan motor issue
3 blinks, pauseIndoor coil temperature sensor issue
4 blinks, pauseOutdoor coil temperature sensor issue
5 blinks, pauseOvercurrent protection activated
6 blinks, pauseAbnormal communication with outdoor
7 blinks, pauseOutdoor fan motor issue
8 blinks, pauseOutdoor high-pressure switch issue

 Common Error Codes

Error CodeMeaning
E101Communication error with indoor unit
E102Communication error with outdoor unit
E201Indoor coil temperature sensor issue
E202Outdoor coil temperature sensor issue
E301Abnormal current protection
E401High-pressure switch error (Outdoor)
E402Low-pressure switch error (Outdoor)
E501Indoor fan motor malfunction
E502Indoor unit heat exchanger sensor issue
E503Indoor unit drain pump issue

Maintenance Tips

No.Maintenance TaskFrequencyTools RequiredNotes
1Clean or replace air filtersEvery 1-2 monthsScrewdriver, vacuumImproves air quality and efficiency
2Clear debris around outdoor unitQuarterlyGloves, hoseEnsures proper airflow and cooling
3Check and clean evaporator and condenser coilsAnnuallyCoil cleaner, brushPrevents reduced efficiency
4Inspect and clean drain linesAnnuallyVinegar, brushAvoids clogs and leaks
5Test thermostat and remote controlBiannuallyNoneEnsure accurate settings and control
6Professional inspection and maintenanceEvery 1-2 yearsHVAC technicianComprehensive check and service

Additional Resources

Resource TypeTitleDescription
Online Guide“Mitsubishi Electric AC Troubleshooting”Official troubleshooting guide from the manufacturer
Video“How to Reset Mitsubishi Electric AC Remote”YouTube tutorial on reprogramming the remote
Forum Post“Blinking Green Light Solutions”User-shared solutions for addressing the issue
User Manual“Mitsubishi Electric Air Conditioner User Manual”Comprehensive guide for setup and troubleshooting
Service Center“Find Nearest Mitsubishi Electric Service Center”Locator for professional assistance and repairs


A blinking green light on your Mitsubishi Electric air conditioner can be indicative of various issues, ranging from minor to more complex problems. Regular maintenance, preventive measures, and a systematic approach to troubleshooting can often resolve common issues. However, when in doubt or faced with more challenging problems, it’s wise to seek the expertise of a certified technician to ensure the longevity and efficiency of your air conditioning system. Remember that timely maintenance and professional servicing can extend the lifespan of your unit and keep it running smoothly for years to come.


Mitsubishi Electric Air Conditioner Blinking Green Light

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