5 HVAC System Sounds You Don’t Want to Hear

May 23, 2019


Without repairs or maintenance, even a new and energy-efficient HVAC system will develop problems. This could lead to loud noises coming from the system. The following are just five possible noises you may hear. If you do hear any of these noises, it’s important to reach out to a technician right away.

1. Banging and Clanging

Broken and disconnected parts will bang inside the system, oftentimes in the compressor and blower unit. The fan blades, in particular, may be hitting against another object. Loose motor mounts can be the culprit as well.

2. Rattling

Loose parts will rattle, so this sound should not alarm homeowners as much as the banging. Rattling may also point to a loose air duct or panel. Parts that are loose or out of balance may also clank.

3. Screeching and Grinding

The sound of screeching—metal against metal—shows that the fan motor bearings are going bad. Problems with the motor bearings and the fan belt may be reflected in a squealing sound. Blower motor units may squeal or screech if they are lacking in a lubricant. If the bearing is about to fail, it may produce a more serious grinding noise.

4. Hissing and Humming

Refrigerant leaks can both damage an HVAC system and harm your health, and these are usually accompanied by a loud hissing noise. Hissing, when not so high-pitched, may denote a leak in the air ducts. Loose parts, especially loose piping, can lead to a humming noise.

5. Clicking

Clicking is normal when the system starts up and shuts down. Continual clicking, though, may indicate an electrical problem. Oftentimes, there is something wrong with the thermostat.

Scott-Lee Heating Company in St. Louis, MO, has more than 40 years of experience to put to work for customers, so you can depend on us for a comprehensive inspection, an accurate repair estimate, and high-quality work. Our technicians have NATE certification, and we maintain an A+ rating with the BBB. Get ahold of us today for more information on our heating and cooling system services. We also offer air quality services and new construction.