Mitsubishi AC Error Code List
If you own a Mitsubishi air conditioner, you may have encountered those cryptic error codes on the unit’s display panel. These codes aren’t just random—they’re the system’s way of telling you something’s wrong. Don’t worry, though! This guide will break down the most common Mitsubishi AC error codes, what they mean, and how you can fix them (or when to call a professional).
Let’s dive in and demystify those codes together!
What Are Mitsubishi AC Error Codes?
Mitsubishi ACs are built with self-diagnostic features to detect faults and protect the system. If something goes wrong—whether it’s a communication problem, refrigerant issue, or power failure—the system displays an error code.
Understanding these codes can save you time and money because you can troubleshoot the issue (or at least give accurate information to a technician).
Common Mitsubishi AC Error Codes Explained
Here’s a look at some of the most common error codes, what they indicate, and their potential causes:
| Error Code | Description | Possible Causes | Solutions |
|---|---|---|---|
| 0403 | Serial Communication Error | Faulty communication between indoor and outdoor units | Check the communication cable and connections. Ensure they’re securely plugged in. |
| 1102 | Discharge Temperature Fault | Compressor discharge temperature too high (over 110°C) | Check for issues with refrigerant levels. Inspect discharge thermistor. |
| 1301 | Low Pressure Fault | System pressure too low (below 1 bar) | Inspect for refrigerant leaks. Check the low-pressure sensor. |
| 1500 | Refrigerant Overcharge | Too much refrigerant, causing low superheat | Recheck refrigerant levels. Adjust if necessary. |
| 2500 | Drain Sensor Submergence | Water detected in the indoor unit’s drip tray | Check for clogs in the drainage line. Clean or replace the drain sensor if needed. |
| 4102 | Open Phase | Missing power phase | Ensure all electrical phases are properly connected. |
| 4255 | Outdoor Fan Motor Error | Outdoor unit’s fan not working properly | Check for obstructions. Inspect the fan motor for wiring or mechanical faults. |
| 5101 | Temperature Sensor Malfunction | Faulty temperature sensor detected | Test the sensor’s resistance and replace it if defective. |
| 6600 | Address Overlap | Duplicate addresses between indoor and outdoor units | Ensure each unit has a unique address in the system’s configuration. |
Deep Dive: Troubleshooting Key Error Codes
1. Error Code 1102 – Discharge Temperature Fault
This error means that the compressor discharge temperature has exceeded safe limits. When this happens, it’s a sign that your system is under stress and could lead to further damage if not addressed.
Possible Causes:
- Overcharged refrigerant
- Blocked airflow (dirty filters or vents)
- Faulty discharge thermistor
What to Do:
- Check the filters and vents: Make sure they’re clean and free of debris.
- Inspect the discharge thermistor: If it’s not reading the temperature correctly, it may need replacement.
- Check refrigerant levels: If overcharged, have a professional adjust the system.
2. Error Code 1301 – Low Pressure Fault
This code indicates that the pressure inside the system is too low. The low pressure could be due to a leak or insufficient refrigerant.
Possible Causes:
- Refrigerant leaks
- Faulty pressure sensor
- Low refrigerant charge
What to Do:
- Look for leaks: Inspect pipes, joints, and fittings for signs of oil or refrigerant leakage.
- Verify the sensor: Use a gauge to compare the actual pressure to the sensor’s reading.
- Refrigerant recharge: If the system is undercharged, call a professional to top it off properly.
3. Error Code 2500 – Drain Sensor Submergence
This error is often caused by water buildup in the indoor unit, which could lead to leaks and water damage if ignored.
Possible Causes:
- Clogged drainpipe
- Faulty drain pump
- Misaligned or defective drain sensor
What to Do:
- Check the drainage system: Ensure the drainpipe is clear of obstructions.
- Clean the drip tray: Remove any debris or standing water.
- Test the sensor: If it’s not functioning properly, replace it.
Common Mitsubishi AC Communication and Power Error Codes
Communication and power-related issues can also cause your AC to shut down unexpectedly. Here’s a quick reference table:
| Error Code | Description | Possible Causes | Solutions |
|---|---|---|---|
| 0403 | Serial Communication Error | Faulty wiring, poor connections, or mismatched units | Check the communication cables, terminals, and indoor/outdoor compatibility. |
| 4102 | Open Phase | Power phase missing or misaligned | Verify proper power supply. Inspect fuses and circuit breakers. |
| 6606 | Communication Fault | Communication failure between the indoor and outdoor units | Ensure correct wiring and system configuration. Test control boards if needed. |
Understanding Sensor and Motor-Related Error Codes
Sensors and motors are essential components of any air conditioning system. If they malfunction, the unit might operate inefficiently or not at all.
| Error Code | Description | Possible Causes | Solutions |
|---|---|---|---|
| 5101 | Temperature Sensor Fault | Sensor malfunction or incorrect wiring | Test sensor resistance with a multimeter and compare it to manufacturer specs. |
| 4255 | Outdoor Fan Motor Error | Faulty fan motor or blocked airflow | Clear any obstructions. Test motor voltage and wiring. Replace motor if needed. |
When to Call a Professional
While you can troubleshoot many issues yourself, there are some scenarios where you should call an HVAC professional:
- Refrigerant issues: Only certified technicians can handle refrigerants safely.
- Electrical problems: If you notice flickering lights or frequent tripping of breakers, leave it to the pros.
- Persistent errors: If the same error keeps coming back even after troubleshooting, it could indicate a deeper issue.
How to Prevent Mitsubishi AC Errors
Prevention is always better than repair. Here are a few tips to keep your Mitsubishi AC running smoothly:
- Clean the air filters regularly: Dirty filters restrict airflow and cause many common errors.
- Schedule annual maintenance: A technician can inspect for potential problems and fix them before they worsen.
- Check the drainage system: Keep the drip tray and pipes clear of debris to avoid water buildup.
- Monitor refrigerant levels: Improper refrigerant levels can lead to both high and low-pressure errors.
Wrapping Up: Don’t Let Error Codes Scare You!
Mitsubishi AC error codes are designed to protect your system and prevent further damage. By understanding the most common codes, you can troubleshoot minor issues and decide when to call a professional.
If you encounter an unfamiliar error code, always refer to your manual or reach out to Mitsubishi’s customer support for clarification. With proper care and maintenance, your AC will stay cool and error-free for years to come!