It’s a classic Singapore story. It’s 2 PM, the sun is blazing, and the humidity is making everything sticky. You’re relying on your trusty Daikin or Mitsubishi aircon for relief, but suddenly, the cool air sputters to a halt. You look up at the indoor unit and see it: a small, green light, blinking relentlessly.
Before you start sweating—from both the heat and the thought of a huge repair bill—take a deep breath. That blinking light isn’t a sign of doom. Think of it as the “check engine” light in your car. It’s your aircon’s smart diagnostic system trying to tell you exactly what’s wrong.
This guide, based on a decade of fixing these exact systems in Singaporean homes, is your first-aid kit. It will help you figure out what that blinking light means, see if it’s a simple issue you can fix yourself, and know when it’s time to call a professional to prevent a small problem from turning into a major one.
How to Read the Secret Codes (Like a Pro)
That blinking light holds a secret message. Here’s how to become an “aircon whisperer” and read the precise error code.
For Daikin Owners: The “Cancel Button” Trick Your Daikin remote is the key.
- Point the Remote: Stand in front of the indoor unit.
- Enter Diagnostic Mode: Press and hold the ‘CANCEL’ button for about 5 seconds. You’ll hear a beep and see ’00’ flash on the remote’s screen.
- Cycle Through Codes: Press the ‘CANCEL’ button repeatedly to cycle through the codes (A0, A1, U0, U4, etc.).
- Listen for the Long Beep: When the code on the remote matches the aircon’s error, the unit will let out a long, continuous beep. That’s your error code! Write it down.
For Mitsubishi Electric (Starmex) Owners: The “Blink Counting” Method For these common units, the remote isn’t used for diagnosis; the indoor unit tells you the code itself.
- Observe the Lights: Pay close attention to the indicator lights on the unit. When there’s a fault, one of them will blink in a repeating pattern.
- Count the Blinks: Carefully count how many times the light blinks before pausing (e.g., blink-blink-blink… pause… blink-blink-blink). This means your error is “3 blinks.”
- Insider Tip: First, check if the horizontal flap (louver) that directs airflow is clipped in securely. If it’s loose, some models will blink continuously as a warning. A firm push to clip it in might fix the problem instantly!
Your Daikin & Mitsubishi Error Code Cheat Sheet
Now that you have your code, use this simple cheat sheet to understand what it means and what to do next. We’ve focused on the most common faults we see in Singapore homes.
Common Daikin Error Codes
| Error Code | What It Means (In Simple English) | Can I Fix It? (DIY or Call a Pro?) | Vedha’s Solution |
| A6 | The indoor fan motor is jammed. The ‘lungs’ of your unit can’t move air. | Call a Pro. This involves electrical components. | Aircon Repair |
| C9 | The air sensor is faulty. Your aircon is ‘numb’ and can’t feel the room’s temperature. | Call a Pro. The sensor needs to be tested and replaced. | Aircon Repair |
| E6 | The compressor motor has a startup error. The ‘heart’ of your system is struggling. | CRITICAL: Call a Pro IMMEDIATELY. Turn off the main circuit breaker. | Compressor Repair / Emergency Service |
| F3 | The system is overheating, likely due to low refrigerant. | CRITICAL: Call a Pro. This often signals a refrigerant leak. | Aircon Repair / Aircon Gas Top-Up |
| L5 | The outdoor unit’s ‘brain’ (PCB) is detecting a serious electrical fault. | CRITICAL: Call a Pro IMMEDIATELY. Turn off the main circuit breaker. | Aircon Repair / Emergency Service |
| U0 | There is a refrigerant shortage due to a leak. | Call a Pro. The leak must be fixed before refilling with gas. | Aircon Gas Top-Up |
| U4 | Communication error between indoor and outdoor units. They aren’t ‘talking’ to each other. | DIY First: Try resetting the main circuit breaker for 20 minutes. If the error returns, Call a Pro. | Aircon Repair |
Common Mitsubishi Electric (Starmex) Error Codes
| Blinking Pattern | What It Means (In Simple English) | Can I Fix It? (DIY or Call a Pro?) | Vedha’s Solution |
| Timer Blinks 2 Times | The indoor temperature sensor is faulty. The unit doesn’t know when to stop cooling. | Call a Pro. This critical part needs professional replacement. | Aircon Repair |
| Timer Blinks 3 Times | The indoor fan motor is faulty. The fan that blows cold air isn’t spinning right. | Call a Pro. This is a mechanical and electrical fault. | Aircon Repair |
| Timer Blinks 5 Times | There is a communication error between the indoor and outdoor units. | DIY First: Reset the main circuit breaker for 20 minutes. If it persists, Call a Pro. | Aircon Repair |
| Timer Blinks 6 Times | The outdoor unit has a serious problem, often with the compressor. | CRITICAL: Call a Pro IMMEDIATELY. Turn off the main circuit breaker to prevent major damage. | Compressor Repair / Emergency Service |
| Power Blinks Continuously | The indoor unit’s ‘brain’ (PCB) is malfunctioning. | Call a Pro. PCB issues are complex and need expert diagnosis. | Aircon Repair |
When to Stop DIY and Call the Experts
You’ve tried the reset, but the light is still blinking. Or maybe you have one of the “CRITICAL” codes above. This is when you put the remote down and call a professional. Trying to fix complex issues yourself is dangerous and can lead to more expensive damage.
- For CRITICAL Codes (E6, L5, 6 Blinks): This signals a major failure. You need our Emergency Aircon Service. Our 24/7 team is on standby to diagnose the issue and prevent further damage.
- For Faulty Parts (Fan Motor, Sensor, etc.): You need our expert Aircon Repair service. Our technicians have the tools and parts to perform the replacement on the spot.
- For an Old Unit with a Major Fault: An expensive repair might not be worth it. Ask our technician for an honest opinion on a new Aircon Installation. The S$400 Climate Vouchers can make a new, 5-tick system a very smart financial choice.
- To Prevent Future Errors: The best solution is prevention. An
Aircon Maintenance contract keeps your system clean and reliable, catching potential issues before they become urgent problems.
Don’t let a blinking light ruin your day. For fast, reliable, and affordable service from experienced technicians, call Vedha Aircon. We’ll get you cool again.
We specialize in Aircon installation, repair, and service. We have all type & model of recon compressor, full set & fancoil. Our technicians are highly proficient in their respective field and repairs and fixes aircon of various brands.
