
Mitsubishi Ductless AC Error Codes: Troubleshooting Guide for Toronto Homeowners
In the heart of a Toronto summer, when humidity soars and the heat becomes relentless, your Mitsubishi ductless air conditioner becomes your best ally. But what happens when it flashes an error code and suddenly stops cooling?
If you’re seeing flashing lights, strange noises, or your home isn’t staying cool, this guide explains everything you need to know about Mitsubishi Ductless AC Error Codes—and when to call for professional ductless air conditioner repair in Greater Toronto.

1. Why Mitsubishi Ductless ACs Display Error Codes
Modern Mitsubishi systems come equipped with smart diagnostic technology that helps protect your investment. Error codes appear to:
Prevent major mechanical failures
Help HVAC technicians pinpoint the exact problem
Alert you to airflow restrictions, refrigerant issues, and other system faults early
Ignoring an error code could shorten the lifespan of your unit or lead to costly repairs. That’s why homeowners across Toronto trust For Saving Home Services Inc., experts in ductless air conditioner repair Greater Toronto.
2. Complete List of Mitsubishi Ductless AC Error Codes and Solutions
Here’s your quick-reference guide for the most common Mitsubishi AC error codes:
🔥 Temperature Sensor Errors
| Error Code | Explanation | Solution |
|---|---|---|
| P1 | Air Intake Temperature Sensor Error | Check for loose wires or replace the sensor. |
| P2 | Heat Exchanger Temperature Sensor (TH5) Fault | Clean or replace the sensor. |
| P9 | Heat Exchanger Temperature Sensor (TH2) Fault | Inspect connection, clean, or contact a technician. |
💦 Drainage System Errors
| Error Code | Explanation | Solution |
|---|---|---|
| P4 | Drain Pan Overflow or Float Sensor Disconnection | Clear blockages; check float switch. |
| P5 | Drain Pump Error | Inspect pump or replace if defective. |
🔒 Protection Mechanisms and System Safeguards
| Error Code | Explanation | Solution |
|---|---|---|
| P6 | Freeze or Overheat Protection Activated | Clean filters and check refrigerant levels. |
| PA | Compressor Shutdown Due to Water Leakage | Inspect drainage and secure connections. |
📡 Communication and Control Board Errors
| Error Code | Explanation | Solution |
|---|---|---|
| E0, E3 | Remote Controller Communication Failure | Check remote batteries and signal range. |
| E1, E2 | Control Board Fault | Professional inspection needed. |
| E9, EE | Indoor and Outdoor Unit Communication Error | Reset system or inspect wiring. |
❄️ Compressor and Refrigerant Issues
| Error Code | Explanation | Solution |
|---|---|---|
| U1, Ud | High Pressure or Overheat Protection Activated | Check refrigerant and clean coils. |
| U2 | High Discharge Temperature or Low Refrigerant Levels | Technician inspection and recharge. |
⚙️ Other Common Mitsubishi Ductless AC Error Codes
U3, U4: Outdoor Unit Sensor Malfunction
U5: Abnormal Radiator Temperature
U6: Compressor Overload or Power Module Fault
U7: Abnormal Overheating
U8: Outdoor Fan Shutdown
U9, UH: Voltage Irregularities
UF: Compressor Overcurrent
UP: Compressor Overcurrent
Fb: Internal Control System Error (Memory Failure)

3. DIY Mitsubishi Error Code Troubleshooting Tips
If your Mitsubishi unit displays a basic error code:
Turn off the system completely at the breaker.
Switch to fan-only mode to thaw any potential icing.
Replace or clean dirty filters to restore airflow.
Reset the system after 5–10 minutes of power-down.
⚡ Important:
If you still see flashing codes or hear strange sounds afterward, call a professional immediately. Attempting complex repairs yourself could void warranties. Our technicians specialize in safe, fast ductless air conditioner repair Greater Toronto.
4. When to Call for Ductless Air Conditioner Repair Greater Toronto
Don’t risk further damage. You should call an HVAC expert if:
The same error code returns after resetting
There’s visible water leakage or excessive ice
The outdoor unit is silent or won’t start
Cooling performance continues to decline
You hear unusual buzzing, hissing, or popping sounds
At For Saving Home Services Inc., we offer urgent service across Toronto, Markham, Vaughan, and the entire GTA for all Mitsubishi error code issues.
5. Why Choose For Saving for Mitsubishi Ductless AC Repairs?
✅ Mitsubishi-Certified Technicians
✅ Same-Day Ductless Air Conditioner Repair Greater Toronto
✅ Transparent Pricing and No Hidden Fees
✅ Access to Parts for Faster Repairs
✅ Recognized as one of the Best HVAC Services GTA
Your comfort is our top priority, and we’ll never leave you sweating through Toronto’s summer heat!
6. FAQs About Mitsubishi Ductless AC Error Codes
Can I reset my Mitsubishi AC to clear an error?
Yes. Turn off the breaker for 5 minutes, then restart. If the error returns, professional help is required.
How often should I clean Mitsubishi AC filters?
Check monthly during high usage periods. Replace or wash filters every 2–3 months.
Will warranty cover Mitsubishi error code repairs?
If your system is under 5–10 year parts warranty, basic repairs may be covered, but labor often is not.
Is ductless air conditioner repair Greater Toronto expensive?
Not always. Basic repairs start around $200, while more complex repairs like board replacements can cost $800–$1,500.
How soon should I fix a flashing Mitsubishi AC error?
Immediately. Small issues escalate fast if ignored, leading to compressor damage or full system shutdowns.
7. Contact For Saving Home Services for Fast AC Repairs in the GTA
Don’t let a flashing error code ruin your summer comfort.
If your Mitsubishi ductless AC is acting up, trust For Saving Home Services Inc.—your experts for ductless air conditioner repair Greater Toronto and the best HVAC services GTA wide.
📍 Serving Toronto, Markham, Mississauga, Scarborough, Vaughan
📞 Call 416-335-0881 Today
🌐 Visit www.forsaving.ca
❄️ Book Your Emergency or Same-Day Appointment Now and Stay Cool!



























