Updated: 2/2/2024

If eerie sounds emanate from your basement or garage, rest assured, it’s probably not ghosts or monsters—rather, it’s likely your furnace. Here’s a breakdown of some unsettling noises you might hear and their possible meanings.

Loud Banging

Are you startled by a loud banging, booming, or popping sound when your furnace kicks in? This could be a sign that the burner is dirty due to dust and dirt buildup. Alternatively, metal ductwork can expand and contract with temperature changes, causing noises. While some noise is normal, especially with metal ducts, if you’re uncertain, you should schedule an appointment with your local HVAC company for a thorough inspection.

Whining or Squealing

Whining or squealing sounds may conjure thoughts of animals or spooky occurrences, but in reality, it’s likely your blower belt. Over time, wear and tear can cause misalignment or looseness in the belt. During your next maintenance check, consult your HVAC technician about this noise. It may simply require lubrication or tightening.


Rattling noises within your furnace typically stem from a loose panel, screw, or, more critically, a leak or crack in your heat exchanger. A faulty heat exchanger poses a serious risk, as it can release carbon monoxide into your home. If you hear rattling, don’t delay—contact your local HVAC professionals promptly to address the issue.


The whistling sound is not a supernatural creature; it’s often a result of restricted airflow due to a clogged air filter. The EPA recommends changing your air filter every three months at a minimum. Try changing the air filter to see if the noise dissipates. If it persists, reach out to HVAC professionals for further assistance in identifying and resolving the cause.


While a low humming sound during furnace operation is normal, it could signal a problem if it becomes noticeably loud. Typically, this is linked to issues with your blower fan or capacitor. To prevent further damage, have a technician inspect and, if necessary, repair your blower motor.

Ensure your furnace is in top condition—schedule a maintenance check with the professionals at American Air, Plumbing & Electric in Oviedo, FL today! Whether you need a diagnostic, repair, replacement, or routine maintenance, our expert team is dedicated to addressing all your HVAC needs. Contact us at (407) 512-9337 or fill out our online form for prompt assistance.

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