H90 - Indoor/Outdoor Abnormal Communication

What does H90 mean?

The indoor unit is not receiving normal data from the outdoor unit. This can happen during cooling or heating operations.

• Faulty outdoor unit main PCB.
• Faulty indoor unit main PCB.
• Incorrect wiring between indoor and outdoor units.
• A broken wire in the connection between the units.
• Disturbed power supply waveform.

Click steps to track your progress.

1. 1

   Check that the wiring between the indoor and outdoor units is correct and secure.

2. 2

   Verify there are no breaks in the connection wires.

3. 3

   Ensure the power supply waveform is stable.

4. 4

   If the issue persists, contact an authorized dealer for PCB inspection or replacement.