Why Is My HVAC System Making That Noise? Common Noises and What They Mean

Is your HVAC system driving you crazy with annoying noises? To better understand the most common and frustrating HVAC noises, we conducted a survey asking homeowners, “What are the most frequent and bothersome noises you hear from your air conditioner or heater?” The results revealed that rattling and buzzing are among the top culprits.

Below, we’ll explore these and other noises, explain what they could mean, and provide solutions to keep your HVAC system running smoothly.

• Banging or Clanking Is your system making loud banging or clanking noises, often metallic in sound? Generally this indicates there is a loose or broken part in the blower motor or compressor of your HVAC system.

• Squealing or Screeching If you hear high-pitched screeching when you start up your system this may indicate that there is a warn-out, damaged belt, motor bearings that need lubrication or issues with the fan motor.

• Rattling According to our survey, rattling was identified as the most common and bothersome HVAC noise. Persistent rattling, especially when you turn your system on or off, could mean that there are loose screws, debris caught inside of the unit or an aging compressor. Tighten any visible loose screws and remove any visible debris surrounding the unit.

• Hissing Continuous hissing or whistling may indicate that you have an air duct leak, a refrigerant leak or an issue with the expansion valve.

• Clicking Are you experiencing frequent clicking when the system starts or stops? This may indicate electrical issues, like a failing thermostat or relay switch.

• Bubbling or Gurgling Hearing water bubble or gurgle in the condenser or refrigerant lines? This may be due to low refrigerant levels or air in the refrigerant line.

• Buzzing Buzzing was the second most frequently mentioned noise in our survey. Persistent buzzing noises from the outdoor unit or compressor may be a sign of loose parts, or debris in the unit or electrical issues. Check for loose components and move away any debris.
  
  

How to Address Common HVAC Noises Unusual noises from your heating and cooling system can indicate underlying issues that need to be addressed. Persistent sounds may signal that there are loose components, blockages, or wear and tear that requires professional expertise. Our survey results confirmed that noises like rattling and buzzing are particularly frustrating for homeowners, making prompt action even more important. Addressing these issues early can prevent further damage and costly repairs.

Preventing Future HVAC Noises Seasonal check-ups before weather extremes are crucial for maintaining your system. Regularly replacing filters reduces system strain, helping to minimize unwanted noises and extend its lifespan.

Improper installation can also lead to ongoing noise issues. With Mint Home, you’re guaranteed a professional installation done right the first time. Plus, we offer maintenance plans to help keep your system running optimally.

If your heating and cooling system continues to make unusual noises, it may need servicing or it might be time for an upgrade. Get a quote today for a new system, and take the first step toward a more comfortable home, noise-free home!