Error 425 - Phase reversal or failure (3Ø outdoor unit) / connection error

What does 425 mean?

For a three-phase outdoor unit, there's either a reversal in the phase wiring (R-S-T-N) or a complete phase failure, or an incorrect connection on the three-phase input.

• Incorrect wiring during installation (phase reversal)
• Loss of one or more phases in the main power supply
• Loose or incorrect connection on the 3-phase input terminals

Click steps to track your progress.

1. 1

   Immediately power off the outdoor unit at the main breaker.

2. 2

   Have a qualified electrician check the three-phase power supply wiring (R-S-T-N) for correct sequence and secure connections.

3. 3

   Verify that all three phases are present and stable at the unit's input terminals.