August 25, 2021

Air conditioner noise isn’t just annoying. It’s a sign that something could be wrong with your cooling system. Learn about identifying nine problematic sounds and how you can fix them.

Noises While Your Air Conditioner Is Running

It’s normal for your air conditioner to be making noise when it starts. This includes noises like:

  • An airplane taking off as the compressor and blower begin running.
  • Steady white noise during the cooling process.
  • A few clicks as the air conditioner turns off.

Here are examples of noises that aren’t normal when your air conditioner is cooling your home.

1. Air Conditioner Making Pulsating Noise

While running, your air conditioner should make a steady whirring sound. If you’re hearing pulsating or rhythmic sounds:

  • More insulation may be needed to dampen sounds from moving parts.
  • A part could be loose, especially if the pulsating sounds metallic.

Fixing both issues requires help from an HVAC technician.

2. Air Conditioner Making Loud Buzzing Noise

Buzzing or humming sounds are often a sign there’s an electrical problem. If your air conditioner compressor is making a buzzing noise, it’s likely getting power but can’t use it because of a problem.

Your air conditioner might also buzz if it freezes. It can freeze due to a refrigerant leak, dirty air filter or dirty coils. In either instance, you’ll need to call a heating and cooling company for air conditioning repair.

3. Air Conditioner Making Rattling Noise

Loose or worn-out parts can make your air conditioner rattle. The top culprits are:

  • Yard debris, like leaves, sticks or rocks.
  • Loose panels or screws.
  • Malfunctioning compressor motor.
  • Damaged or misaligned fan.

An HVAC professional can quickly identify and correct any rattling problems. We also recommend scheduling annual air conditioning maintenance. This cleaning and inspection service keeps your air conditioner running smoothly and rattle-free.

4. Air Conditioner Making Whistling Noise

Air conditioner making a whistling noise outside your house? It’s trying to tell you it’s low on refrigerant, which it uses to transfer heat. Other signs of a refrigerant leak include:

  • Air conditioner runs for a long time but struggles to cool your home.
  • High indoor humidity.
  • Sweet smell near the air conditioner.
  • Frozen air conditioner.

You’ll need an HVAC technician to repair a refrigerant leak. If your air conditioner was installed before 2011 and runs on R-22 Freon, we recommend considering air conditioning installation. R-22 isn’t being made anymore because of its harmful effects on the ozone layer. It’s expensive since only limited quantities are available.

Not to mention, a new air conditioner will keep you more comfortable and potentially lower your energy bill. The newer it is, the less likely it is to have problems.

5. Air Conditioner Making Gurgling Noise

Gurgling, bubbling and water noises can mean you have:

  • A refrigerant leak.
  • A clogged condensate drain line.

Your air conditioner naturally creates water during the cooling process. This water pools in a condensate drain pan then flows out of your home through a drain line. Over time, mold can grow in the drain line and cause water to back up in your home.

AC Mechanical can break up the clog quickly and keep it from happening again through our air conditioning maintenance program.

6. Air Conditioner Making Crackling Noise

Crackling, popping and sparking noises shouldn’t be ignored. They can mean:

  • Debris has been sucked into your air conditioner.
  • Your air conditioner is frozen.
  • There’s a wiring problem.
  • Your ductwork is expanding, contracting or vibrating.

If your air conditioner is making noise after rain, it’s possible water seeped inside components that are normally waterproof. Whatever the problem is, AC Mechanical can take care of it quickly and affordably.

Noises When Your Air Conditioner Is Turning On or Off

7. Air Conditioner Makes Loud Noise When Starting

Hearing banging every time your air conditioner turns on? There could be yard debris inside it, or a fan might be loose. We recommend shutting off your air conditioner to avoid further damage and calling us at 307-778-0515 for assistance.

8. Air Conditioner Makes Loud Noise When Turning Off

If your air conditioner is making noise after shutting off, there are a couple things that can be wrong:

  • Air filter is too restrictive. This applies to pleated filters over a MERV 10 rating.
  • Air filter is dirty and needs to be changed.
  • Ductwork is expanding or contracting because it’s undersized or not reinforced properly.
  • Indoor blower wheel is loose or out of balance.
  • Compressor has a broken spring.
  • Outdoor fan is loose.

We recommend starting with your air filter. Check the MERV rating and that it’s clean. If that doesn’t fix the problem, our professionals can help.

9. Air Conditioner Makes Clicking Noise When Off

If you’re hearing clicking when your air conditioner turns off, a loose fan in the outdoor unit could be to blame. This can be caused by wear and tear or a lack of maintenance. Call AC Mechanical at 307-778-0515 to fix the problem.

Trust Us with All Your Air Conditioning Repair Needs

As your local Lennox® Premier Dealer™, AC Mechanical guarantees you’ll be satisfied with our air conditioning repair in Cheyenne, WY.  We’re highly skilled when it comes to solving loud air conditioner noise, so give us a call at 307-778-0515 to schedule your appointment today.

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