The Scary Sounds Your AC May Make

Scary sounds plugging ears

If you hear scary sounds coming from your air conditioner, you’re probably wondering if these sounds are normal. When the AC unit strays away from the usual humming sound, you’re used to hearing from your indoor air handler or outdoor unit. The scary sounds of your AC could mean common air conditioning issues requiring a repair from Trust Heating & Air to fix it.

If you hear these sounds coming from your air conditioner, it could mean there is something in the system that needs to be replaced or repaired:

  • high-pitched squealing noise 
  • banging noise 
  • clicking noise
  • buzzing noise 
  • hissing noise
  • rattling noise

A fan motor, fan belt, expansion valve, blower fan, condenser fan, relay switch, refrigerant piping, compressor, and other parts in the unit can make such noises when they mess up.

Below, Trust Heating & Air will explain more about the causes of the most common air conditioner noises and some tips on what can be done to fix them. When it’s time to call a professional for AC repair services, turn to our team at Trust Heating & Air to investigate system sounds and put an end to your worries about an air conditioner making unusual operating noise.

Scary sounds plugging ears

If Your AC Makes These Scary Sounds, Call Us!

Buzzing Sounds

If you hear loud buzzing noises from your air conditioner, you can go ahead and assume it’s malfunctioning. 

Typically, the issue is either:

  • missing or broken isolation feet
  • loose parts
  • missing refrigerant leaks
  • malfunctioning compressor

Each part of your air conditioner works together to keep your home cool from the warm outside temperatures. So, when one part comes loose, it puts extra stress on the other parts. After excess wear puts enough pressure on those parts, your unit can start making a buzzing sound that indicates a need for repair.

Your unit’s compressor sits on tiny rubber feet called “isolation feet” at the base of the air conditioner unit. After using your AC for a while, those feet can disintegrate or crack, making the compressor lose balance and make a buzzing noise while it’s being used.

Air conditioning units can freeze up as they’re used to cool your home. Your AC can become frozen if refrigerant starts leaking from the unit, which makes a buzzing sound.

The issue could also come from a malfunctioning compressor, the part of the unit that pressurizes and cools down the refrigerant; that keeps your home cooled off. A buzzing noise could mean your compressor isn’t working correctly or your unit’s electrical voltage isn’t proper.

When buzzing comes from frozen coils within the indoor unit, the system needs to be thawed:

  1. Switch the thermostat from cool mode to the off position. Allow the air conditioner to rest and turn it off until all ice melts.
  2. Switch the fan setting to on instead of auto; this allows the blower fan to run constantly and push warm air over the frozen coils, to help the ice melt.
  3. Inspect your air filter. If it is dirty, replace it with a clean filter. A dirty filter is often the reason for a frozen air conditioning system.
  4. After the ice has melted away from the coils, turn the thermostat back to cool and the fan back to auto.

If your evaporator coils freeze up again, call a professional for repair services. Often, a new air filter solves this problem, but a more serious issue is at play when freezing continues.

Banging Noises

If you can hear a banging sound coming from the air conditioner, this indicates a problem with the unit’s compressor. This part is engineered to distribute refrigerant to various parts of the HVAC system. It removes excess heat from your home. As your central AC system nears the middle or end of its lifespan, it is not unusual for parts to become loose inside the compressor.

Once the parts start to detach in the compressor, you may notice a rattling noise. This sound is caused by separate components hitting the compressor’s exterior framing. At the same time, your air conditioning system is activated. 

Since the compressor is not designed to be easily disassembled, you may have to give in and invest in a new air conditioner unit. If your air conditioner is producing a banging sound, call Trust Heating & Air.

Rattling Noises

In a best-case scenario, your AC may be making rattling noise because of dirt, loose sticks, or leaves in your outdoor condenser unit. The best way to fix this issue is to disassemble the unit to remove these items. In a worst-case scenario, a damaged electrical contractor in your system may produce this air conditioner sound. Suppose you happen to notice a malfunctioning contractor. In that case, this should be fixed as soon as you can to prevent further damage to the compressor of your central AC unit.

Clicking Sounds

You may have heard a clicking noise at the beginning or end of your cooling cycles. Still, it is not customary to hear a continuous clicking sound from your air conditioner. This type of sound may indicate a broken thermostat. Since the process of removing and installing a new thermostat is not simple, call a licensed tech at Trust Heating & Air.

air filter

Screeching Sounds

The most common problem when it comes to an air conditioner making a screeching noise is a malfunctioning fan motor; in the outdoor condenser unit. The central air conditioning system connected to your house features a fan that’s made to withdraw heat from the refrigerant. If your AC unit is making a shrieking noise, this indicates an issue with the fan motor. The sound may also be because of a broken motor in the compressor of the condenser system.

A screeching noise could also be because of a damaged blower fan motor inside your house. The unit’s blower fan is made to collect warm air from each room of your home. When the blower fan is turned on, the hot and humid air throughout your enclosure will be collected by your return ducts and sent to your air conditioning system. Next, the blower fan will distribute the cold air from your system throughout your house. 

You could also notice a screeching sound near the HVAC system in your home because of damaged bearings in your fan motor. Another reason could be an impaired fan belt may be the root cause of this noise. If you hear unusual AC sounds, immediately deactivate your air conditioner, and call a professional at Trust Heating & Air.

Humming Noises

A humming noise inside your air conditioner is due to a defective contactor relay switch. This part is designed to start the outdoor condenser unit when it receives a signal from your thermostat. 

Unfortunately, you can not turn on your air conditioner until a licensed technician inspects this issue. 

Do not ignore electrical problems in your system. This will cause severe damage to your central air conditioning system, which expensive repairs will accompany.

Hissing Noises

If your air conditioner is making hissing noises, this may signal a moderate to severe air duct leak in your home. This sound may also be the cause of a malfunctioning expansion valve or an air filter that is not compatible with your system. Immediately call Trust Heating & Air to perform an inspection of your air conditioning system.

Bubbling Sounds

The air conditioner connected to your home could make a bubbling noise due to excessive moisture. This type of problem may be produced by a crack, blockage, or hole in your drainage pipe. If you are a handy person, it is easy to disassemble your AC unit to inspect the drainage line. 

However, we do not recommend replacing the drainage line alone. To fix the bubbling sound in your air conditioner, you will need specific skills, training, special tools, and equipment. Please call a certified technician at Trust Heating & Air to ensure the job is completed correctly and safely.

No More Scary Sounds Air Conditioner Repair, Tune-Up, & Installation Services

Call our team or book an appointment online if you notice a scary noise coming from your air conditioner; call Trust Heating & Air for a tune-up. We provide installation services to homes in Loganville, GA, and surrounding cities. We also offer other HVAC services, including gas and furnace repair, central humidifier repair, central air cleaner repair, and much more.

Trust Heating & Air technicians are trained using the latest techniques to ensure effective and long-lasting solutions.