San Diego home and business owners rely on air conditioning systems to keep their spaces cool and comfortable. When the summer heat is in full force, the last thing they want is an HVAC that can’t keep up—or worse, stops working altogether. ACs can stop suddenly or fail to cool properly without warning.
However, squealing, grinding, hissing, and other unusual air conditioner noises are often sure signs that something’s not right. Be prepared for the San Diego heat with professional HVAC repairs, maintenance, and installation services from Bill Howe—contact us today.
Don’t Ignore Your AC’s Warning Signs
Some air conditioner noises are normal, while others can signal that you need a professional diagnosis or it’s time for a new HVAC system. Air conditioners rely on compressors, condensers, evaporators, and other components for consistent and reliable cooling. During normal operation, these components produce noises from a steady hum to a light whooshing and are completely normal. AC units can also emit a brief clicking noise when cycling on or off, which is a normal part of the process.
When your AC is making noise, it’s essential to understand what the sounds mean so you can know when it’s time for professional HVAC services. Ignoring sounds that aren’t typical for air conditioners can lead to the need for potentially costly parts and repairs, as well as a shortened lifespan for your unit. Don’t ignore weird AC noises if you want to enjoy a comfortable, cool environment in your home or business.
If your HVAC is less than 15 years old and has been properly maintained, the only thing you should hear is a subtle hum and the movement of crisp, cool air entering your space. No matter what air conditioner noises or other signs have you concerned, Bill Howe Heating & Air can help you diagnose and fix them.
The 9 Common Air Conditioner Noises and What They Mean
An AC making weird noises can be a concern because they are often a warning sign of an HVAC issue. Whether it’s a constant buzzing or an intermittent squealing, understanding the cause of a noisy AC unit is the first step in getting your air conditioner back to normal.
- Banging or Clanking
If your AC is making a loud noise like clanking or banging, worn-out parts and components could be the cause. Fan motors, blades, mounts, blower motors, belts, and compressors are common causes due to damage or wear and tear.
- Hissing or Whistling
An AC making noises like whistling or hissing could be caused by insufficient airflow or a blockage. Restricted vents, dirty air filters, refrigerant leaks, and failing blower motors can all cause whistling sounds that may be constant or heard repeatedly.
- Squealing or Screeching
Squealing and screeching sounds can be caused by high internal pressure, which is a serious safety issue that should be checked out immediately. More often than not, a screeching or squealing air conditioner noise could be the result of a failing belt, fan motor, or compressor.
- Buzzing
A buzzing sound from your AC unit, whether constant or only once in a while, can be caused by loose screws, dirty fan blades, and other minor issues. A persistent buzzing from an air conditioner could mean a more serious problem, from faulty electrical connections to leaking refrigerant.
- Rattling or Chattering
Common reasons your AC is making noise like rattling or chattering could be from wobbly fan blades, loose screws, or debris buildup around an HVAC unit. If your air conditioner consistently rattles and chatters, the causes could range from a faulty compressor to a dirty air filter.
- Clicking
Clicking sounds when an AC starts or stops are okay, but repetitive clicking while the unit is running is cause for concern. Bent or obstructed fan blades, bad relay switches, or damaged compressors and motors can cause constant clicking sounds.
- Gurgling or Bubbling
An air conditioner noise that makes bubbling or gurgling could have a refrigerant leak, a blocked condensation drain, or a damaged expansion valve. These types of sounds often indicate a problem that could cause further damage and costly repairs.
- Humming
An AC making a humming noise is typical and comes from the steady operation of the fan motor and blades. If you notice humming noises that are unusual or occur when the AC isn’t operating, they could be caused by an electrical or mechanical problem.
- Thumping or Thwapping
If your AC is making a loud noise like thumping or thwapping, it could be a sign of unsecured or damaged components or parts. Broken fan blades, excessive debris, and failing compressors are a few of the most common culprits.
Compressors can cause many unusual noises when they are damaged or failing, including hissing, banging, and squeaking. Typical wear and tear, electrical issues, or overheating can cause compressor issues. If the compressor or another major component is failing, it may be time to consider upgrading to an efficient and quiet modern HVAC system.
Preventative Maintenance: Your Best Defense Against Noisy AC Units
HVAC maintenance is one of the most effective ways to prevent unusual air conditioner noises and ensure reliable cooling. Preventative maintenance typically includes cleaning, checking refrigerant levels, testing electrical components and connections, and lubricating moving parts. Professional AC maintenance offers many benefits that save money and give home and business owners peace of mind.
- Better air quality
- Increased efficiency
- Fewer repairs and replacements
- Longer, more productive lifespan
- Lower energy costs
- Warranty protection
Professional HVAC companies recommend scheduling annual preventive air conditioner maintenance in the spring, before the California heat rolls in. Regular maintenance helps keep your AC in top shape for dependable cooling performance.
When to Call a Professional HVAC Technician
If your AC is making noise, no longer cools well, or uses noticeably more energy than usual, investing in a professional HVAC inspection from Bill Howe is a smart idea. An HVAC service technician checks your AC from top to bottom, diagnoses issues, and offers cost-effective and proven solutions. Bill Howe HVAC is a family-owned local business that has helped thousands of customers across San Diego keep cool and stay warm since 1980.
Discover expert HVAC repair, maintenance, and installation services that fit your cooling needs and budget. Call 1-800 BILL HOWE (245-5469) and we’ll figure out why your AC is making weird noises and help you stay cool and comfortable all summer long.
