Why Is My Air Conditioner Making Noises?

lady closing her ears

Modern AC units feature two-stage compressors that make them very efficient. Further, they sport noise-dampening technology that keeps noise levels less than 55 dB. This means that if your unit starts making unusually loud noises, something is amiss.

The noises might mean your system needs a simple tune-up. However, when you ignore them, the simple issues can become exacerbated and turn into major issues that require you to replace the unit. You need to listen to the kind of noise the unit makes in order to make an accurate diagnosis. The information below will help you decide whether you need to call a professional immediately or wait until your next routine maintenance appointment.

1. Airflow Problems That Cause a Whistling Noise

Whining and whistling noises are a sign of airflow interruptions. This normally occurs when the filters clog with dust and contaminants. When the filters trap enough particles, the particles block them, and this limits airflow. This should not be cause for alarm as you can clean or change the filter without calling a professional. Again, if you follow a maintenance schedule with a professional, you should never have to deal with a clogged filter.

The whistling noise might also result from damaged ducts. If ductwork cracks from many years of use, air might escape from the crack, resulting in a whistling noise.

If you recently replaced any part of your AC, the new parts might cause airflow obstruction. If these parts are not compatible with your system, the vents might produce a whistling noise.

2. Loose Parts That Cause Shaking or Rattling Noise

Rattling noises coming from your AC are an indication of loose parts. Parts of the AC that move a lot, such as the motors, might loosen and create a shaking noise. Ducts can also loosen and shake to make a rattling noise.

If one or more screws in your unit go loose, the parts that the screw held together might produce rattling noises. In such a case, you do not need a professional as long as you have a screwdriver. While at it, check the screws and bolts that hold the AC unit to the concrete floor. If the screws or bolts are loose, the AC might shake and bang against the wall.

If you experience loose nuts and screws often, you need to schedule routine maintenance with Buckeye Heating, Cooling & Plumbing. We can help prevent these issues before they become detrimental.

3. Damaged Motor and Compressor Resulting in Screeching Noises

If your AC produces squeaking, screeching, or squealing noises, it is an indication of compressor and motor problems. The sounds result from ungreased bearings, damaged motors or compressors, or slipped blower belts.

Damages to the motor or compressor need immediate repairs from a professional. Your compressor is responsible for circulating the refrigerant, and when broken, your home will no longer cool as needed.

4. Electrical Problems Causing a Buzzing Sound

A buzzing sound is common, and it indicates an electrical problem. In most cases, the sound comes from failing relays and contractors.

Some other electrical problems that can result in a buzzing sound include a broken capacitor, loose wiring, arcing, a failing motor, and a malfunctioning compressor. This is a problem that needs a professional to fix. If you have any of these issues, call a professional immediately to wade off an electrical hazard.

5. Fan Problems Causing a Humming Noise

A broken or less-maintained fan will produce a humming noise. You can avoid the noise by maintaining your fan regularly and keeping it clean.

If one or more parts of the fan wear out or break, say a bent blade or a malfunctioning motor, the fan will produce a humming noise.

6. Leaking Refrigerant Resulting in a Hissing Noise

A hissing noise results from leaking refrigerant. However, an AC that is always running or one that doesn’t cool well can also produce a hissing sound. You should call a professional immediately you hear a hissing noise. The professional will check all parts for leakages.

A hissing sound can also result from an air filter that doesn’t fit correctly or an expansion valve that doesn’t match your AC system.

It is not common for refrigerants to leak as long as you keep up with your system’s regular maintenance. When you neglect your coils, they corrode and result in cracks and holes through which the refrigerant leaks.

The refrigerant runs in closed loops within your air conditioning unit. The thin copper coils that carry the refrigerant can develop cracks and holes and result in leaks. Because the refrigerant moves under high pressure in the coils, it produces a hissing sound when it escapes.

7. Coil Problems Resulting in Constant Running Noise

If your AC unit produces constant running noises, the coils have a problem. Bent coil fins are the main causes of that constant running sound.

Again, if the coil fins clog with dirt and grime, the AC will still work, but less efficiently. This running noise shows that the AC is struggling to reach a set temperature. Note that if you do not take care of this problem, it can lead to a system breakdown.

To correct the issue, you only need to clean the condenser coil and the evaporator.

8. AC Compressor Problems Resulting in a Banging Noise

The AC compressor wears and tears from constant use. Due to this, some parts inside the AC might become loose, and these create the loud banging noises you hear.

Compressor problems need a professional to fix. In most cases, a professional will recommend a replacement. However, technicians can correct issues with the condenser and not the compressor.

9. Other Issues and Noises

There are times your AC unit will produce a clicking noise. There are many reasons this might happen. The cause is dependent on where and when the noise happens.

If the clicking noise occurs when the AC is running, the noise might come from an object that is obstructing the movement of the blower fan. When this object hits the spinning fan, it creates a clicking noise.

The clicking noise may also occur when you start the AC and might cause the AC to fail to start. In such a case, you may have an electrical problem within the compressor, the thermostat, or the capacitor.

You might also hear a clunking noise from your AC if you fail to lubricate the motor. This problem is not common if you maintain your AC regularly. You will hear a clunking noise if you fail to maintain an old AC model.

Lubricating your AC motor is supposed to be an easy feat, but the AC is high voltage. You need to be cautious when working on it or, better yet, call a professional to help you out. If you have to lubricate it yourself, switch off the unit.

Stop the Noises

The noise from your AC indicates something is amiss. You can fix most of the noises through routine AC maintenance. A professional will help you decide whether to repair or replace the AC unit based on its age, condition, repair history, and extent of the damage.

Call Buckeye Heating, Cooling & Plumbing Today

At Buckeye Heating, Cooling & Plumbing, we offer installation, repair, and maintenance of heating and cooling systems for homes and businesses in Worthington, OH. You can call us for indoor air quality, gas furnaces, and heat pumps. We also offer financing. Call Buckeye Heating, Cooling & Plumbing today to learn more about our services and financing options.

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