P3 - System error (Transmitting/receiving signal) in indoor unit

What does P3 mean?

This code indicates a system communication error related to transmitting or receiving signals within the indoor unit or between units.

• Loose or damaged communication wiring.
• Electromagnetic interference.
• Faulty control board in the indoor unit.
• Incorrect address settings for multi-split systems.

Click steps to track your progress.

1. 1

   Turn off the main power to the entire AC system at the circuit breaker for 5 minutes, then turn it back on.

2. 2

   Verify that communication cables are securely connected between indoor and outdoor units, and to control boards (requires professional access).

3. 3

   If the error persists, contact a qualified HVAC technician to check communication lines and control board functionality.