After air conditioner installation, inspect the indoor unit to confirm it is mounted level and firmly secured to the wall bracket with no wobbling or gaps. Check that the drainage pipe is properly sloped and draining water to the outside, and verify that the refrigerant line connections are insulated and free from visible damage or oil stains that could indicate a leak. Test all available modes including cooling, fan speed, and timer functions to ensure the controls are responding correctly, and check that the outdoor unit is stable, properly secured, and positioned with adequate clearance on all sides. Finally, confirm with the technician that the refrigerant pressure was checked, the system was vacuumed before charging, and that you have received the warranty card and installation documentation.