back to blog

Why Is My HVAC So Loud?

Air conditioner maintenance being performed on HVAC unit outside brick home.

Clanking, rattling, hissing, buzzing, and whistling. When your heating or cooling unit starts to make loud noises, it can be as annoying as it is concerning.

These common sounds are often the first signs that an HVAC system needs a maintenance check or repair. Being aware of the different types of sounds your system can produce will help you better understand the root cause of an issue.

When that banging in the background becomes hard to ignore, it’s time to address the problem or call a Faszold Heating & Cooling professional.

Loud HVAC unit? We’re here to help. Call (314) 656-7399 to speak to a Faszold specialist in St. Charles or St. Louis County.

5 Reasons Your HVAC Is Suddenly Louder

First, it’s important to note when the loud noises began and in which type of unit. An HVAC system that’s outdoors, indoors, or has a dual heating/cooling function will have different factors determining the cause of noises.

HVAC units may be impacted by:

  • Blocked vents
  • Disjointed or dislodged parts
  • Improperly sealed or loose ductwork
  • Outside debris in an exhaust fan
  • Underlying thermostat issues

Schedule Your Service Today!

Outdoor Units

Outside HVAC systems, like an air conditioner’s condenser unit, are exposed to elements like twigs and branches. This debris can get lodged in exhaust fans, causing a rattling sound. To resolve this, try turning off the outside unit’s power before checking for any obstructions.

If you notice any damage or misshapen parts, call a professional, and don’t attempt to remove a blockage on your own.

Indoor Units

Indoor units, like furnaces or ductless air conditioners, are usually prone to clicking, squealing, or banging.

In the case of furnaces, a clicking sound after a long inactive period means your heater is warming up. Call a professional if the clicking persists, as you may be dealing with a pilot light malfunction.

In air conditioning units, banging or clicking noises are likely the result of dislodged parts like a motor or a coil. Squealing or high-pitched whistling shouldn’t be taken lightly in ACs as they may indicate a refrigerant leak or compressor failure.

Turn off your AC unit immediately, and call an HVAC technician. Don’t turn the unit back on until it’s resolved by a professional.

Vents & Registers

Hissing and humming are often the sounds reported from vents and register systems. Closed or blocked vents are the likely culprit since airflow is being cut off. In certain cases, loose ductwork may be to blame.

We recommend calling a technician if you notice hissing or vibrating sounds from your vents. Internal ventilation systems aren’t easily accessible to untrained homeowners and should only be handled by professionals.

Schedule With Faszold Today

If you’re dealing with a clanging or clicking HVAC unit, a factory-trained Faszold technician will promptly address the issue.

Our 40+ years in business have given us a range of experience in residential and commercial HVAC systems, from brands like Amana, Bryant, Carrier, Comfortmaker, Coleman, Daikin, Goodman, Heil, Honeywell, Lennox, Mitsubishi, Rheem, Trane, York, and more.

Customers in St. Charles and St. Louis County have relied on our upfront pricing and Faszold Club Membership Program for the best local services. Schedule a consultation or at-home visit today so we can restore function to your heating or cooling systems.

When you choose Faszold, you choose absolute comfort. Speak to one of our HVAC professionals today by calling (314) 656-7399.

Our Promotions

Free Air Purifier With New System Expires 04/30/2024 *Call Faszold for details
0% Financing For 18 Months Expires 04/30/2024 *Call Faszold for details
Up to $3,135 In Rebates Expires 04/30/2024 *Call Faszold for details.
$89 A/C Tune-Up Spring Special Expires 04/30/2024 *Call Faszold for details.
$1,999 New State 40 Gallon Water Heater Expires 04/30/2024 *Call Faszold for details
Free Service Call with Qualifying Repair Expires 04/30/2024 *Call Faszold for details

Request Service

Fill out the form below, and one of our team members will reach out to you shortly!

Request Service

truck m_truck

Become a Part of the Faszold Family

Sign Up for the Faszold Club Membership Program
  • Significant energy savings
  • Prevents equipment breakdowns
  • Extends the life span of HVAC systems
  • Discounts on repairs
  • Priority service
View Club Memberships