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Why Is My AC Making Loud Noises?

AC Repair, Troubleshooting
July 24, 2023
AC System Making Noise Rock Hill SC
Elite Air & Heat, LLC HVAC Contractor Favicon

Elite Air and Heat

As the summer heat builds in South Carolina, homeowners rely on their air conditioning systems. A well-functioning AC ensures a season of comfort for your family, while a malfunctioning AC can be a severe disruption to your daily routines – including necessary sleep quality.

We’ve covered common AC problems like why warm air sometimes blowswhy your AC can take a while to cool the house, and why it doesn’t turn on. But what about when your AC makes loud noises?

To help you troubleshoot, in today’s blog, we’re exploring the underlying causes (and solutions!) of the following:

We’ll also discuss how regular AC maintenance can help you avoid these problems altogether. With a little know-how, you can enjoy a summer of uninterrupted comfort and peace of mind.

Need fast and efficient AC repairs?

Contact the friendly and highly-trained technicians at Elite Air and Heat today. We’re a locally-owned and family-operated team committed to getting all your AC repair needs done right the first time. We also offer 24/7 service for those can’t-wait emergencies and back up our work with a 100% satisfaction guarantee.

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Hissing and Whistling Noises

A couple of factors can lead to hissing and whistling noises. The first is a refrigerant leak, and the second is a possible problem with the ductwork. Let’s take a closer look at each of these potential problems.

  • A refrigerant leak is a leak in the refrigerant lines that circulate cooling chemicals between an air conditioning system’s indoor and outdoor components. When this system is fully functional, it is a closed loop. If it springs a leak, the refrigerant chemicals will make a hissing noise as they come into contact with the air. The problem will typically be accompanied by a sharp drop in the unit’s cooling efficiency and warm air from your AC vents.
  • Problems with your ductwork can also produce hissing and whistling if your system’s air ducts are too narrow or have sharp bends that constrict the airflow. This can be accompanied by a stuffy atmosphere in the home, doors frequently slamming shut on their own, or even mold growth on your vents.

If you find signs of either of these problems, it’s important to contact HVAC pros like the experts at Elite Air and Heat to address them. Refrigerant leaks are toxic and require a qualified technician to address them safely. For ductwork issues, they can recommend partial repairs or redesign as needed. You can count on Elite to advise only the needed work and complete it promptly, safely, and efficiently.

Clicking and Buzzing Noises

Clicking and buzzing sounds are generally indicators of electrical system problems. If your inside or outside AC unit is making a loud buzzing noise, there are several possibilities:

  • The control panel may be faulty. Errant electrical signals to the panel can produce clicking sounds and sparks.
  • The thermostat may have a faulty part. A part likely needs replacing if there’s a buzzing noise when you change the thermostat’s settings.
  • The wiring may be loose or exposed. Loose wiring can lead to a disconnect with the AC’s circuit breaker, producing a buzzing noise. Exposed or loose wiring can lead to constant sparks.
  • Clicking or buzzing may indicate that the circuit breaker itself is broken.
  • A failure in the capacitor or contactor components on an outdoor unit may have occurred. The capacitor provides electricity to the unit, and the contactor starts it up. Continuous clicking can indicate that the unit is trying and failing to initialize.

Any indicator of problems with your wiring, control panel, or circuit breakers should prompt you to shut down the unit immediately and call an electrician. Sparking is a hazard that requires an especially urgent remedy, and trouble with your circuit breakers may indicate deeper electrical issues.

If there appears to be a failure in your unit’s capacitor or contactor components, you should contact your local HVAC professionals.

Rattling and Banging Noises

Rattling and banging typically indicate something loose inside your AC unit. This could be something as minor as a loose screw or potentially more serious. Here are some of the possibilities:

  • Loose parts have broken off to vibrate against the bottom or sides of the unit. This can be caused by a failure in an internal fan’s mount that allows its blades to make contact with the casing.
  • If your outside AC unit is making loud noises, leaves and twigs loose inside the unit may be the culprits.
  • Failure of the springs holding your refrigerant pump can lead to the pump making contact with the compressor and causing loud noises.
  • A problem with the compressor may be at fault. If the unit shakes when it’s operating, the compressor may be improperly mounted or in the process of failing.

Whatever the specifics, you don’t want loose material rattling inside your AC unit. Any problem affecting the compressor, the heart of any AC system, is especially urgent. In that case, you should immediately shut the unit down and contact a professional.

How HVAC Maintenance Helps Avoid These Issues

An expert technician will always be happy to help in an emergency but don’t wait until your AC unit makes loud noises. Save time and money when you schedule a regular check-up for your air conditioning system. Elite’s HomeTeam Service Plan provides an annual 53-point checkup at an affordable price to catch issues before they develop into serious problems.

Turn to the leading local team for expert AC repairs and maintenance!

We’re proud to be a top-rated HVAC company in York County, as proven by our hundreds of 5-star reviews. We offer advice you can trust, convenient scheduling, up-front and honest pricing, and the highest standards of workmanship. Call us at (803) 570-8835 or click below to schedule your appointment online today.

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