Loud rattling or buzzing noise from the indoor unit during operation.

Safety first: Turn off power before opening the unit.

Steps:

• Check filters and panel: Ensure filters are properly seated and the front panel is fully closed and latched.
• Inspect blower: Look inside the blower area for loose objects (screws, plastic, insects) and remove them.
• Secure pipes: If copper pipes are touching the plastic housing, gently reposition them and add foam insulation or padding to prevent vibration.

If noise persists: The indoor fan motor or wheel may be out of balance and require replacement by a technician.