E474 (Red Blink, Green Blink, Yellow OFF) — IPM or PFCM Temperature sensor error

What does E474 mean?

The outdoor unit's PCB LED displays E474 when a temperature sensor associated with the Inverter Power Module (IPM) or Power Factor Correction Module (PFCM) reports an error. This helps monitor critical component temperatures.

• Faulty temperature sensor
• Issue with the Outdoor Inverter PBA
• Overheating of the IPM or PFCM

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit at the circuit breaker for 5 minutes.

2. 2

   Ensure the outdoor unit has proper ventilation and that its heatsinks are clear of dust and debris.

3. 3

   Restore power and attempt to restart the system.

4. 4

   If the error persists, contact a qualified technician to inspect the temperature sensors and the Outdoor Inverter PBA.