What’s that noise? Is it a normal noise—or is something wrong? It’s no secret that most HVAC systems make “some” noise, but it’s crucial to know the difference between “okay” noises versus sounds that indicate a problem.

If your air conditioning system is silent, that could also be a bad thing. No noise is not necessarily “good” noise, so how can you know which sounds are a part of normal system operation? Which sounds should tell you it’s time to call an HVAC specialist? Keep reading to learn more about HVAC noises.

The Normal Noises

Smooth HVAC operation comes with a few noises that indicated all is well. If you hear any of these sounds, you can rest easy and enjoy comfortable temperatures in your home. “Normal” noises include:

  • The thermostat “click.” Under normal operation, the thermostat “clicks” to tell the unit to start heating or cooling. You’ll often hear another click as the thermostat tells the unit to turn off again.
  • Gurgling or hissing inside the unit. Depending on whether the furnace or the cooling unit turns on, you’ll hear the unit “gurgle” to heat or cool the air before it begins circulating the air through your ducts.
  • “Clicking” as the furnace ignites. Your furnace has a standing pilot light or electronic ignition. To heat the air, the ignition “clicks” on, then heats the gas that warms the air circulating through your system.
  • Airflow. When the system begins to move air through your ducts and vents, you’ll hear a soft roar of the blower creating airflow.

As you become familiar with your HVAC system, you’ll recognize the familiar sounds of a well-running system. However, if any of these noises sound different—or you hear new noises—this could indicate a problem.

The Abnormal Noises

There’s no need to spend significant amounts of time listening to your AC or furnace. However, “bad” noises should be obvious when you hear them. As soon as you hear any of these abnormal noises, it’s time to call an HVAC technician to investigate a potential problem:

  • Squealing. There could be an obstruction inside your unit or air ducts. Squealing noises can indicate that your system struggles to push air efficiently through the unit and into your home. A squeal can also signal that the blower belt is about to break.
  • Knocking or thumping. As ductwork expands and contracts, you might hear knocking or thumping. However, if the sound gets louder or more frequent, you could have loose components—or pests inside your system.
  • Booming. When the pilot light fails to ignite the gas in the furnace, you might hear booming noises.

These noises can indicate a problem before it occurs. If you hear these noises, stop using your system and call an HVAC professional right away!

Know Your HVAC Noises To Protect Your System

Knowing your HVAC noises can help protect your system! At the first sounds of a problem, contact the team at Sewell Electric & HVAC to inspect your system and recommend a solution.