Indoor unit displays F1, unit may not respond to remote

Safety first: Turn off power before accessing the control box.

Steps:

• Check address settings: On multi-split systems, verify that the indoor unit address DIP switches or rotary switches are set correctly and uniquely for each indoor unit.
• Inspect receiver PCB: Remove the front panel and locate the IR receiver board. Ensure its connector to the main PCB is secure.
• Test remote: Use a smartphone camera to check if the remote’s IR LED flashes when buttons are pressed. Replace batteries or the remote if no signal.
• Replace receiver board: If the remote works but the unit does not respond and F1 persists, replace the receiver PCB.