Remote control not operating the indoor unit

Steps:

• Replace batteries: Install fresh, correctly oriented batteries in the remote.
• Check remote operation: Point the remote at a smartphone camera; pressing buttons should show a flashing light on the camera screen (indicates IR output).
• Clear line of sight: Ensure nothing blocks the IR receiver window on the indoor unit and clean it with a soft cloth.
• Try manual operation: Many Hitachi units have an emergency ON/OFF button under the front panel. Press it to verify the unit itself works.

If the remote works (IR flashes) but the unit does not respond: The IR receiver board or indoor PCB may be faulty and require replacement.