Every unusual AC sound points to a specific issue. Clicking is different from hissing, which is different from grinding. Identify the exact sound you hear — we'll explain the likely cause and when to act.
See if any of these signs match your device — each one increases the likelihood of this fault.
These are the causes we encounter while repairing AC making unusual noise — ranked from most to least common.
Repeated clicking = weak start capacitor unable to fire the compressor
High-pitched hissing = pressurized refrigerant leak in the copper lines
Grinding = outdoor fan bearings worn out
Regular knocking = compressor lost internal balance — needs replacement
Heavy vibration = loose mounting brackets or unit not installed level
Water-like sound = refrigerant moving abnormally — leak indicator
Any of the following = a danger signal — call now and don't try to fix it yourself.
On-site diagnosis, clear pricing before any work, and a documented 6-month warranty.