Why Is My HVAC Making a Strange Noise?

Heating and cooling equipment makes normal startup, airflow, and operating sounds. A new banging, grinding, squealing, or strong buzz is different.

Rattling

A light rattle can come from something loose or debris around the equipment. Don't open HVAC equipment to hunt for a loose internal part.

Squealing

A persistent high-pitched squeal can involve airflow or moving components. If it's new and doesn't stop, it's worth having checked.

Grinding

Grinding isn't a sound to live with. If continued operation sounds mechanically damaging, shut the system down.

Banging or clanking

Sharp mechanical sounds can point to a loose or damaged component. A severe new sound is a good reason to stop using the system until it's been checked.

Buzzing

Some equipment hums naturally. A new, loud electrical buzz, especially alongside poor operation, heat, odor, or breaker problems, deserves attention.

When should I act quickly?

Stop the system if you notice a burning odor, smoke, repeated breaker trips, severe grinding, or violent mechanical sounds. If the sound is new, severe, or getting worse: Find Local HVAC Help