Why Does My Air Conditioner Make Noise After Shutting Off?

Few noises are scarier than an unexpected, loud bang — especially if it happens to be coming for your air conditioner. If you’ve started to notice a loud slamming sound after your system shuts off, there could be a number of underlying issues at play. While it can be difficult to determine the exact issue without having a professional diagnose your unit, there are a few common causes that can help you better understand whether or not professional repair services are needed.

AC Units & Their Main Components

Before we dive into what the cause of your noisy air conditioner might be, it’s helpful to understand what the main components are within your system and how they operate. The following are just some of the critical parts of your cooling equipment that you should be able to identify: 

  • Air filter: Responsible for filtering out airborne contaminants from your home’s air supply, the filter in your unit should be replaced at least once every three months.
  • Air handler and blower: These two parts work together to draw air from inside your home to the evaporator and then distribute that air throughout the home. 
  • Evaporator: The air conditioning’s evaporator is located in the cold area of the unit and is responsible for receiving liquid refrigerant and transforming it into gas, working to cool and dehumidify the air indoors.
  • Condenser: Acting as the counterpart to your evaporator, condensers are located in the hot side of the AC unit and work to bring hot, condensed refrigerant gas to the outside of your home to help vent heat and transform the gaseous refrigerant back into a liquid.
  • Compressor: Working in tandem with your condenser, the compressor aids in transforming the refrigerant back into a liquid by pressurizing refrigerant gas. This component is also located on the hot side of the unit.
  • Expansion valve: Assisting the evaporator, the expansion valve is located between the condenser and evaporator and is responsible for regulating the amount of liquid refrigerant that moves to the evaporator.

Understanding these four major components of your cooling equipment can help you pinpoint the underlying problem causing slamming sounds after system shut-off.

Common Causes of Air Conditioning Noises & Malfunctions

There are many reasons why your air conditioner lets out a loud bang after powering off. The following are just some of the most common component malfunctions that can cause loud noises to emanate from your unit depending on where you hear them in your home: 

If the Noise Comes from Inside… 

  • An air filter may be slamming against the grille, which can be caused by an air filter that’s too restrictive, too dirty, or if you have undersized return ducts.
  • Some units have dampers in place to change the amount of airflow circulating to different parts of the home. The slamming you hear might be the damper closing after the unit shuts down.
  • You may have expanding or contracting ductwork that’s causing the slamming sound after the system shuts off.
  • There may be an issue with your air handler that’s causing the blower wheel to bang against other components within your system.

If the Noise Comes from Outside…

  • Your compressor’s support springs might have reached the end of their life span, causing it to become unbalanced and allowing the refrigerant pump to bang against the case of your compressor.
  • The fan in your outdoor unit might require motor repair or replacement as loose components cause banging sounds.

Professional vs. DIY AC Repair

Despite what one might think, resolving a slamming sound in your air conditioning system can be a complex project. More than simply tightening a few loose parts, correcting loud sounds in your AC unit requires years of industry experience and specialized tools. By requesting help from a professional cooling specialist, you can: 

  • Reduce your risk of injury, such as electrocution
  • Catch additional repair needs before escalation
  • Save on the need for complete system replacement
  • Improve your AC unit’s reliability and performance

If you’re experiencing loud banging sounds when your air conditioner shuts down, don’t hesitate to get the professional AC repairs you need from the Air Experts! 

Schedule Emergency Air Conditioning Repair Today!

For more than 30 years, the Air Experts have offered exceptional cooling services that families can trust. Our team is dedicated to your 100% satisfaction, offering the following Super Seven Guarantees to each of our valued customers: 

  • Comfort guarantee
  • No frustration guarantee
  • Low price guarantee
  • 30% utility savings guarantee
  • Property protection guarantee
  • Installation date guarantee
  • Timeliness guarantee

Restore full functionality to your cooling system in no time by scheduling emergency air conditioning repair with the Air Experts today!

Get In Touch Today
Ask us a question or request service today!

The technician was right on time, diagnosed the problem quickly and was able to repair the issue. Very satisfied with the service.

Read Full Testimonial

Discover the Difference

Affiliations:
Leave Us a Review on Google