Air Conditioner Makes Loud Noise When Starting

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It should not surprise you to hear sounds coming from a machine. No home will be completely silent because there is usually something running in every home, like a fan, a fridge, a washing machine, or a dishwasher. Even an air conditioner unit will emit a sound when it kicks on and starts cooling your home. However, if your air conditioner makes loud noise when starting, that’s a sign of trouble and you should investigate it. It could be a symptom of a serious air conditioner issue. This article addresses some causes as well as the solutions for loud air conditioning units.

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Why Does My Air Conditioner Make A Loud Noise When It Starts?

When an air conditioner is starting it should do so somewhat quietly. Different noises can mean different problems with the unit. Each sound can point to a single issue that should be addressed. Call a qualified HVAC technician for help should you hear your air conditioning unit produce unusual sounds.

Various Air Conditioner Noises & Their Causes

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1. Air Conditioning Unit Is Clanging & Banging

The outdoor unit uses a blower motor to move air around. When the blower is damaged, it might start to make clanging or banging sounds. Parts can move out of place and hit against the cage. Debris, thermal expansion, or damper movement could also be causing this noise.

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2. Air Conditioner Makes A Screeching Sound

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If it sounds like metal grinding on metal, you possibly have broken bearings in your fan motor. While it is not an emergency, you should call an HVAC technician and have them repair it soon.

3. Air Conditioner Starts Clicking

A clicking sound likely indicates an electrical issue. If you try to start the unit but the air conditioner doesn’t turn on, it could be in the wiring. This problem should be turned over to a professional HVAC contractor who can focus on repairing the capacitor, compressor, or thermostat.

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4. Cooling System Is Pulsating

A quiet pulsing sound happens when air flows through a cooling system. However, a pulsating noise that comes from the outside AC unit should never be able to be heard inside. If you do hear that sound, you should check your outdoor unit for twigs or broken fan blades.

5. Air Conditioner Makes Whirring Sounds

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This kind of noise likely results from mechanical problems and may come from either the indoor or the outdoor part of your unit. Commonly, this sound will be traced to a broken belt or faulty blade, or it may be bearings going bad or fan motor failure. Turn the unit off right away and call your technician for air conditioner repair work.

6. Air Conditioner Makes A Buzzing Or Humming Sound

If the outside air conditioning unit starts an audible humming, check for debris trapped in it. Leaves, twigs, or branches may have slipped through the holes into the unit. Remove any debris that has found its way into the case. Buzzing may also indicate a fan that’s starting to go bad.

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7. Air Conditioner Is Making A Rattling Noise

Rattling is usually from loose air conditioner parts because of vibration. Test all the screws and bolts in the unit and give them a quick tightening. Call an HVAC contractor to come and clean all the coils and replace your air filter. Always call an HVAC company for a yearly air conditioner maintenance visit.


Common HVAC Contractor Repairs For Noisy Air Conditioning Units

1. Coil Fins Need Cleaned & Straightened

Keep coil fins clean if you want to improve both performance and efficiency. You can call an HVAC contractor to schedule an annual air conditioner unit tune-up. They will have a fin comb that can straighten coil fins and will also bring a vacuum that has the right brush extensions to get every bit of dirt from the area.

2. Tighten Up Any Loose Screws In Your Air Conditioning System

Because an AC unit has a lot of moving parts, an air conditioner will likely vibrate while it’s running. This can cause fasteners to loosen over time. After a while, rattling may be heard every as soon as it switches on. Routine HVAC maintenance will include tightening up the unit’s screws.

3. Clear All Of The Debris From The Blades

Open up your air conditioning unit’s cabinet to inspect the interior. If you find debris, remove it from the system. Pay attention to foreign objects anywhere near the fan blades. This quick and easy task is something any homeowner is able to do.

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4. Straighten Bent Blades

After removing all the dirt and debris, you need to check the blades for any abnormalities. Uneven blades need to be gently put bent back in the correct shape. Reach out to your HVAC contractor if you find bent blades as a tech can perform this task correctly to ensure smooth operation.

5. Lubricate The Air Conditioner Motor

Screeching sounds often indicate a need for lubrication in the motor. This can be done with tune-up service, and regularly oiling the right parts will prevent issues from occurring at all. The HVAC tech knows the proper oil to apply and where to apply it. Also, they can add oil to ports located below the fan’s motor.

What To Do If An Air Conditioner Gets Noisy

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First, check the unit’s outdoor fan and inspect the entire unit. The condenser fan is found at the center of an outdoor unit. If it still rotates, watch how the blades spin. Any signs of it being even slightly off-balance could indicate there’s debris inside the casing. Look over all the coils and check the refrigerant piping, too. If you have concerns about handling this yourself, call on a professional.

Next, you should change the HVAC air filters, which is an important task for all homeowners. An HVAC unit will not run well if its filters are clogged. The unit will be struggling, inefficient, and may make a humming sound. Inspect your air filters monthly. Replace them when they need it.

After this task, you should be sure to clean the outdoor unit because it is vulnerable to the elements around it. Dirt, debris, and insects can get in through the vents. For safety’s sake, be sure you turn off the unit before you ever open the case. Take off the top grill and carefully remove fallen objects. Don’t forget to close it when you finish.

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After cleaning your unit, turn the air conditioner back on to see if the fan has started to spin again. If it still is not able to move, jumpstart it using a stick to carefully push the blade, which will create some momentum. If the blade begins to spin, the problem likely lies in the run capacitor.

Sometimes the problem is indoors, not in the outside unit. Once you finish your inspection, you should look at the indoor air handler. Look for ice build-up and see if it has any bent coil fins. Turn off the power so it thaws. Let the unit dry before you start it again.

There are things that a homeowner can do to prevent air conditioner problems or to stop some of the typical noisy issues. But there are limits to what individuals without training are able to do. If, after doing everything listed here, you can still hear noises, call an HVAC professional and ask for help.

Preventive Measures For Air Conditioner Starting Problems

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Here are some preventive measures you can take for air conditioner starting problems:

1. Install A Noise-Reduction Barrier

A noisy air conditioner makes it harder to focus on daily tasks. It even disrupts sleeping patterns. Help prevent this by putting up a barrier that will reduce the noise. Noise-reducing fences or sound blankets help with this. Before anything, talk to an HVAC contractor to see what will work best for your unit.

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2. Schedule HVAC Maintenance at Regular Intervals

Yearly air conditioner maintenance will help keep your air conditioner running well. With trained eyes, HVAC technicians are able to find problems when they start. They then are able to intervene with quick solutions to prevent any problems from growing worse. Have an air conditioner contractor conduct annual thorough cleanings to reduce the likelihood of loud air conditioner noise from developing.

3. Rely On a Good HVAC Expert

Call an experienced HVAC contractor immediately if you hear unusual air conditioner noises. Ignoring them is unwise as they can evolve into a worse problem quickly. It is more affordable to repair a minor cooling system problem than it is to find solutions for a full-blown AC system failure.



You should pay attention to what your air conditioner unit sounds like as it can tell you when something is not working right. Manufacturers try to create units that will minimize noise. Note what’s normal by listening to your AC. As soon as something seems off, you should investigate it. Turn to a capable professional technician who is able to provide more advanced repairs.

Call Point Bay Fuel For Any HVAC Repair Requirements


For superior heating and cooling services in Ocean and Monmouth County, New Jersey, call Point Bay Fuel. Our team is made up of the best-certified technicians who offer excellent HVAC tune-ups, repairs, installations, and more. You can count on our techs to bring their knowledge and skill when servicing your HVAC system.

We are proud to offer competitive heating or cooling service costs. Our maintenance services will keep you comfortable, improve energy efficiency and reduce the heating and cooling costs for your home. If require HVAC repair or need a replacement system, let one of our skilled techs recommend the best solution for your situation while staying within your budget. We back up our work with a satisfaction guarantee. Call Point Bay Fuel today and be sure to inquire about an in-home consultation.

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