Manufacturer diagnostic code

Back to all Mitsubishi Electric MUZ-FS12NAH*** codes

Mitsubishi Electric MUZ-FS12NAH*** 12 blinks / restart troubleshooting

Compressor phase-current detection failure. Document the displayed code and operating conditions before scheduling service.

What this code means

The official model-family manual identifies 12 blinks / restart as compressor phase-current detection failure.

Code
12 blinks / restart
System area
Compressor power
Priority
Urgent
Applicable code set
Mitsubishi Electric MUZ-FS outdoor-unit failure indications

Safe checks

  • Confirm the thermostat is on, set correctly, and calling for heating or cooling.
  • Check the air filter and visible return-air path for obvious airflow restrictions.
  • Record the displayed code or flash sequence before scheduling service.

First step

Record the code, avoid repeated reset attempts, and schedule GreenFlow service.

Frequently asked questions

What does 12 blinks / restart mean on a Mitsubishi Electric MUZ-FS12NAH***?

The official model-family manual identifies 12 blinks / restart as compressor phase-current detection failure.

What should I safely check before scheduling service?

Use only the visible, non-invasive checks listed on this page. Do not open equipment panels.

When should GreenFlow handle this code?

Call GreenFlow if the code repeats, the equipment is locked out, heating or cooling is not restored, or the condition involves gas, ignition, pressure, wiring, a motor, or a control board.

Manufacturer source document