Normal HVAC Sounds
Some noise is expected: gentle humming from motors, quiet airflow, soft clicks when cycling on/off. New sounds or louder-than-normal sounds warrant attention.
Banging or Clanking
Often indicates a loose or broken part—blower wheel, motor mount, or connecting rod. Turn off the system to prevent further damage.
Squealing or Screeching
Usually a belt issue (older systems) or bearing problem. Bearings may be failing. Address soon before motor damage occurs.
Clicking or Ticking
Occasional clicks during startup are normal. Continuous clicking without startup indicates control or ignition problems. Call for service.
Hissing or Bubbling
Hissing suggests refrigerant leaks. Bubbling in refrigerant lines confirms leakage. Turn off the system and call for repair.
Rattling
Usually loose panels, screws, or debris in the system. Check accessible panels and screws first. Persistent rattling needs professional inspection.