U4 - Malfunction of transmission between indoor and outdoor unit (Indoor/Outdoor Unit)

Was bedeutet U4 ?

There is a communication failure between the indoor and outdoor units.

• Damaged communication wiring
• Loose connection
• Interference from other devices
• Faulty control board on either unit

Klicken Sie auf Schritte, um Ihren Fortschritt zu verfolgen.

1. 1

   Turn off power to both units.

2. 2

   Inspect communication wiring for damage and ensure secure connections.

3. 3

   Restore power and check if communication is re-established.

4. 4

   If the error persists, contact a service technician.