Error Code: PC 13 – AC Power is Cut Off or AC Voltage Detection Circuit Fails

Error Code: PC 13 – AC Power is Cut Off or AC Voltage Detection Circuit Fails

What this means:
The system has detected a loss of AC power or a failure in the AC voltage detection circuit on the outdoor main PCB. This often occurs during unstable power conditions or if the PCB’s voltage sensing circuitry is faultyTS44.

Try this first (quick reset):

1. Power off the unit completely.

2. Wait 2 minutes.

3. Turn the system back on once power supply is stable.

• If the error clears — power has normalized.

• If the error remains — continue with voltage checks.

Next steps (for technicians):

1. Check the power voltage at the outdoor terminal:

   • If abnormal → wait for power to stabilize, then restart.

   • If still abnormal → inspect wiring and terminals.

2. Measure voltage between L and N terminals:

   • If incorrect →

     • Reconnect wires properly.

     • Repair or replace damaged wiring.

3. If voltage is normal but fault persists:

   • Replace the outdoor main PCB.

What you might need:

• Outdoor main PCB

• Power supply wires

• Multimeter for voltage checks

Helpful tip:
This protection is especially common in systems with safety shut-off valves and during brownouts. Always verify power quality before concluding PCB failure.

Click here to view the detailed guide.TS44