What each Mitsubishi Electric code means — and what to do next. Stuck? AAA Comfort Air fixes Mitsubishi Electric systems across Central NJ, often same-day.
Mitsubishi Electric is the gold standard in ductless mini-splits. When something is wrong, the indoor unit blinks an indicator LED or shows a code so the fault can be pinpointed fast.
The indoor unit’s OPERATION/indicator LED blinks a fault, or a code shows on the board or remote. Count the blinks or read the code. The indicator is a blinking indicator LED / code (e.g., E6, P4, U4).
| Code | What it means | What to do |
|---|---|---|
| E6 / E9 | Indoor–outdoor communication error | Wiring or power-up sequence — call us |
| P4 | Drain (condensate) sensor fault | Clogged drain / sensor — call us |
| P5 | Drain pump / overflow fault | Condensate overflow — call us |
| P8 | Pipe (coil) temperature fault | Refrigerant/airflow — call us |
| U4 | Indoor–outdoor communication / wiring error | Call us |
⚠️ Codes can vary by model and control-board revision — always confirm against the label inside your unit’s access panel. For any gas, electrical, or refrigerant fault, call a licensed technician.
The indoor unit’s OPERATION/indicator LED blinks a fault, or a code shows on the board or remote. Count the blinks or read the code.
You can try one power cycle at the breaker to clear a one-time fault. But if the same code returns, it’s a real fault — repeatedly resetting a gas or electrical issue can be unsafe. Call AAA Comfort Air at 609-665-3022.
AAA Comfort Air installs and repairs Mitsubishi Electric systems across Cream Ridge and Central New Jersey, with same-day and 24/7 emergency service. Call 609-665-3022.
Book online or call your local Mitsubishi Electric HVAC team — same-day & 24/7 emergency service.
