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Why Is My Air Conditioner So Loud?

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Is a noisy HVAC system keeping you up at night?

Here's something you already know: your air conditioner is supposed to help you go to bed comfortably, not keep you awake. You need an HVAC system inspection if it is too noisy to sleep through.

It would be best if you didn't leave it untreated for too long. While it may not be detrimental to your unit, it may eventually lead there.

Noise issues don't cause mechanical problems but are effects or symptoms of a malfunction. Call a professional HVAC technician for a proper diagnosis.

Please familiarize yourself with all the possible causes and what noises they produce.


An HVAC technician might ask you about the noise level, and what sounds they emit. These questions are typical for estimating costs and the equipment they will need to conduct repair services.

Strange noises don't just come out of thin air. If your AC unit hasn't undergone routine maintenance and tune-up for a long period, you may expect to find multiple underlying causes.

Your loud air conditioner may be due to something caught in the air duct system, dislodged fan belt, or electrical issues. No matter how small the issues are, you need to call a professional as soon as possible.

You can read plenty of articles online to help you come up with your own diagnosis and ways to rectify them. However, jumping to conclusions may only make you anxious and proceed haphazardly. Don't cause more damage by trying to save a few bucks, especially if you hear a loud noise.

Take a noisy AC as a sign to enlist HVAC maintenance and repair services.

Should I Be Worried About My Noisy Air Conditioning Unit?

A little screeching sound or rattling noise coming from your outside compressor is normal. However, an HVAC unit making too much noise, too frequently, or too loudly is cause for concern.

Strange sounds may indicate problems with your blower motor and different parts coming loose. Your air conditioning unit may be in serious trouble.

What Causes a Loud Air Conditioner?

Air conditioners only produce a loud sound when there are mechanical issues. Barely audible sounds may result from its functions, such as vibrating and turning fan blades. A loud air conditioner is alarming, activating your senses into a stress response, which might explain why you can't sleep at night.

If your gut tells you something is wrong, trust it. Here are the most common issues encompassing all kinds of HVAC systems.

Poor Maintenance & Installation

Amateur contractors and electricians without HVAC expertise may get measurements wrong. An unlicensed contractor might install your unit at improper angles, causing mechanical failure. You should leave AC installation to reliable pros to avoid issues later.

If your HVAC system doesn't undergo regular AC maintenance, one loose part may have already caused a domino effect and lead to a refrigerant leak or other problems with the entire HVAC layout.


When one component comes loose or malfunctions, it leaves the rest of your HVAC system to compensate. Compensating for other elements can overwork another, causing disruptive noises, insufficient heating, and a surge in your energy bills.

If you don't notice the noises, look at your monthly bills to see if there are discrepancies. If your HVAC system is costing you more monthly but underperforming, it may have internal elements overcompensating for each other.

Loose Parts

Dislodged parts may be the effects of improper installation and maintenance. However, parts coming loose may also occur out of nowhere. An animal or a foreign object may fall onto your outdoor unit and dislodge internal components. While they are screwed in, they may succumb to heavy impact.

Dislodged parts are typically an easy fix. Still, they may scratch or tear into other components and cause leaks.

Refrigerant Leak

A refrigerant leak is a common risk with air conditioning units. Worse than having loose parts banging around your air conditioner are dislodged parts tearing into your refrigerant storage. Harsh chemicals may freeze the rest of your HVAC system and warrant more extensive services to remedy.

If your air conditioning is only producing warm air, leaking, and emitting unusual odors on top of the sounds, a leak may be to blame.

What a Noisy HVAC System Sounds Like?

Because there are many reasons behind your noisy air conditioner, the sounds they make may vary. Here are the most common noises reported by homeowners in Portland.

Rattling Noise

A rattling noise is a sign of various debris within air ducts or your outdoor unit. Your condenser fan motor may be saturated with microparticles producing rattling noises from its vibrations.

While a rattling sound doesn't indicate extensive damage, your fan blades, blower motor, and various coils may short-circuit due to damaged wires. Microparticles may also cause clogs, overworking your fan belt.

Buzzing Noise

A buzzing noise indicates an electrical issue and often leads to short-circuiting. If the rattling turns into a buzzing noise, chances are microparticles have damaged electrical components within your air conditioner system.

It would be best if you didn't attempt to dismantle your AC unit or handle its blower motor. Your entire HVAC system is interlinked. If there's a loud buzzing noise coming from one area of your HVAC unit, all of its metal parts may already cause electrocution.

Hissing Noise

A hissing noise coming from your outdoor unit may indicate high air pressure buildup seeping out of outlets or microabrasions. Your HVAC system facilitates airflow and it isn't impossible for it to store air pressure.

The high pressure buildup is a more likely occurrence for air ducts. More air is fed through ductwork for whole-home distribution. However, when some air vents are closed or minimized, airflow is redirected back to other vents for release. Still, without proper channels to exit, pressure may stagnate within ducts. You might then hear hissing noises from your air vents.

Screeching Noise

A screeching noise is distinct. Screeching isn't like rattling sounds, like little components cling clanging around. Screeching sounds like nails on a chalkboard. Your air conditioning unit may have tiny debris scratching up various metal components in its interior.

If you hear screeching instead of rattling, your AC unit may already be in serious trouble. Call for immediate AC service before it snowballs into worse problems.

Squealing Noise or Whistling Noise

When you hear whistling or squealing from your compressor, it indicates your AC system has leaked. A refrigerant leak freezes anything it settles on, including your AC unit's coils and motors. While a leak may not immediately warrant extensive repair, an HVAC technician will need to replace the refrigerant storage.

They should conduct a full maintenance service while at it, ensuring none of the other components need replacement. Refrigerant is a harsh chemical and may cause corrosion to the rest of your AC system.

Whistling doesn't indicate a leak but is a sign of pressure buildup. Refrigerant saturating your AC unit leads to clogs and pressure buildup. If you don't have ducts and hear whistling, there may be a leak in your mini-split air conditioner AC.

What Should I Do About Unusual Noises?

Always keep all ventilation inlets and outlets away from obstructions or clog-causing particles. An enclosed environment abundant with hair and other larger particles will clog your AC unit or air filters and cause odors and sounds. Dander and hair are abundant if your house is home to people and pets. It is best to keep furry friends outdoors, but we understand if you like them cuddled up next to you in bed.

Open natural and mechanical ventilation systems to prevent your indoor environment from filling with contaminants. A saturated air filter may eventually fall apart, causing a popping sound. Filters have sharp edges, and coming apart sends screws, shrapnel, and other components clanging around your HVAC system.

Your compressor is exposed to the elements outdoors and requires just as much care and attention as HVAC components indoors. It holds the blower motor and is the brain of the entire operation. Neglecting to check on its well-being may result in poor heating and cooling. Again, regular maintenance prevents any unusual occurrences and lengthens the lifespan of your AC system.

Count on reliable experts to service your air conditioner to prevent problems from occurring.

Sunset Heating and Cooling | Electric

If you need reliable and affordable AC repair in Portland, Sunset Heating and Cooling has the guys for you! Our team of experts prioritizes efficiency and transparency. We will make sure we take the stress out of this mess.

Whether it is AC installation and replacement or maintenance service you need, we can help you get your fix today.

Cheaper or amateur technicians may promise quick and easy fixes, but they won't prioritize your long-term comfort as we will. You can count on us and our guarantees to ensure your AC unit doesn't keep you up at night due to loud sounds or poor air quality.

Take a look at our list of cooling services to find what you need, and book your appointment online. Call our hotline for any immediate concerns.

(503) 500-5866

What Our Clients Say

Sunset went out of their way to help with my project and David was amazing. Great job and look forward to future projects.

-Todd T.

Roman did an awesome job. I had the trifecta, new AC unit ,furnace and hot water heater. Courteous, and competent service. I highly recommend Sunset Heating & Cooling.

-Charles E.

Eduardo provided excellent service when he repaired our AC. I felt his effort was over and above expected. Polite and professional at all times. Good job!

-William G.

Caring, professional and helpful. Thanks for making things happen quickly and getting my Dear friend's heating back up and running in such a quick manner. You went above and beyond for a family in need and that is very much appreciated. Thanks from the whole group!

-Kristina K.

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