Display shows F5, unit may not respond to remote or may operate erratically

Safety: No internal high-voltage work is required for basic checks, but unplug the unit if removing covers.

Steps to resolve F5:

• Replace batteries: Install fresh, high-quality batteries in the Friedrich remote control, observing correct polarity.
• Clear line of sight: Ensure there is no dirt or obstruction over the IR receiver window on the front of the unit.
• Test remote output: Point the remote at a smartphone camera and press a button; you should see the IR LED flash on the camera screen. If not, the remote may be faulty.
• Reset unit: Unplug the air conditioner for 5 minutes, then plug back in and test again.
• Receiver board: If the remote is working but the unit does not respond and F5 persists, the IR receiver board or main PCB may need replacement.