Outdoor unit is very noisy during operation; rattling, buzzing, or grinding sounds are heard.

Safety first: Turn off power before touching the outdoor unit.

Steps to try:

• Tighten screws: Check the top cover, grille, and fan guard for loose screws and tighten them.
• Inspect fan blade: Ensure the blade is not cracked or rubbing against the shroud. Adjust or replace if damaged.
• Secure piping: Look for copper lines touching metal surfaces and add foam insulation or clamps to prevent rattling.

When to call a technician: Grinding or metallic noises from the compressor or motor bearings require professional replacement.