Loud HVAC systems can be a sign that a repair from a licensed HVAC technician may be required.

Why is my HVAC fan so loud?

Posted: April 14, 2023 at 9:05 am
By: Lakes Region HVAC

When your heating, ventilation, and air conditioning system is operating normally, the sound of the system's fan should be barely noticeable. A loud fan within an HVAC system could indicate a problem. While a trained technician should confirm the exact issue, this blog post will discuss the most common reasons why an HVAC fan would be louder than usual.

  1. Dirty/Clogged Air Filter:

    A dirty or clogged air filter is a common and easily fixable cause of increased fan noise. When the air filter is dirty, it restricts air movement causing the fan to work harder to maintain airflow throughout the unit. This increased workload can cause the fan to make more noise. Be sure to evaluate how often you must change your filter based on its type and your preference. For example, filters that are more effective in filtering small particles get dirtier faster since they trap more debris. Consult your HVAC technician to see exactly how often you need to change your filter. Many filters need to be changed four times a year. Two of these times you can eliminate if you get bi-yearly maintenance visits. A clean filter is also essential to maintaining healthy indoor air quality.

  2. Worn Motor Bearings:

    The motor bearings in your HVAC system can wear out over time, causing the motor to make what's often described as a humming or buzzing noise. If you hear this hum or buzz when the system starts up or shuts down, this is a likely cause of the noise. Your fan's motor bearings may need to be lubricated or replaced.

  3. Loose or Damaged Fan Blades:

    If the fan blades in your HVAC system are loose or damaged, they can cause the fan to wobble or vibrate, leading to a noticeable racket. In some cases, loose or damaged blades can even hit the sides of the unit, causing a loud banging sound. Call an HVAC technician to get the blades tightened or replaced.

  4. Blower Motor Issues:

    The blower motor in your HVAC system is responsible for moving air through the ductwork. If there's an issue with the blower motor, it can cause the fan to make a loud noise. Common problems with blower motors include worn or damaged belts, loose or damaged pulleys, or a malfunctioning motor. In addition to being annoying, this sound also indicates that your system is running inefficiently. Another sign of this issue is an unexplained increase in your energy bills.

  5. Improperly Installed Ductwork:

    If the ductwork in your HVAC system isn't properly installed, it can cause air to flow unevenly through the system, leading to noise. If this is the case, the sound will be particularly noticeable in the ducts near the fan, where the noise is amplified. Unfortunately, you may need to have your ductwork repaired or reinstalled.

If you have questions regarding your heating or cooling, give Lakes Region HVAC a call.

If you are experiencing a noisy HVAC fan, it is vital to have the system inspected by a certified HVAC technician to determine the cause of the problem and the best course of action to fix it. If you have any questions, one of our trained professionals can advise you further.

If this article is useful to you, or if you know someone who can benefit from it, please Share it.

Have another question? Contact the Lakes Region team, and we’ll find your solution.

Our clients are homeowners, small business owners, and corporations—and one could be you by calling 603-286-2290 or emailing info@lrhvac.com.

About Lakes Region HVAC
Since 1992

Lakes Region’s expert service technicians and installers are trained in the latest advancements in heating and cooling technologies. We'll help you select the correct comfort system for your home, ensuring that your equipment operates at the highest efficiency — giving you the lowest monthly operating cost.

Visit our website.
Follow Lakes Region HVAC
Contact Lakes Region HVAC

LRHVAC’s office hours: Monday - Friday 7:30-4:30
Phone: 603-286-2290
Mail: 86 Bay Hill Rd., Northfield, NH 03276
Email: Email us

More info.