Unit displays E7 or remote icon flashes; remote control does not operate the Koldfront air conditioner.

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

Steps:

• 1. Replace batteries: Install fresh, correctly oriented batteries in the Koldfront remote.
• 2. Clear line of sight: Ensure there is a clear path between the remote and the unit’s IR receiver window on the front panel.
• 3. Test remote output: Point the remote at a smartphone camera and press buttons; you should see a flashing light on the camera screen if the IR LED is working.
• 4. Clean receiver window: Wipe the front panel where the receiver is located to remove dust or film.
• 5. Panel receiver check: If the remote works (IR flashes) but the unit does not respond, the IR receiver on the display board may be faulty and the display board may need replacement.