Why Is Your Air Conditioner So Noisy?

It’s summer in Louisville, and that means it’s time to flick on your air conditioner and ride out that heat wave in comfort. When your unit kicks on, though, it greets you with a horrible noise. Whether it’s banging, grinding, or rattling, you’re worried that it means something is seriously wrong with the air conditioner.

Some air conditioner noises are normal, while others will require repairs from an HVAC technician. Below, learn about the top causes of a noisy air conditioner and what to do about them. If your unit continues to make noise, call us for air conditioner repair in Louisville, KY.

What’s Causing That Awful Racket?

Before we dive into the causes of worrisome air conditioner noises, let’s discuss the sounds that your unit is supposed to make. When the unit kicks on, you’ll hear a soft hum, which is the sound of the compressor getting ready to start a cooling cycle. The air conditioner will also make a gentle whooshing noise while it runs, and that’s the sound of the fan turning.

If you put your ear up to the air conditioner, you might hear the sound of moving water, which occurs when water moves through the unit into the drainage system.

When the cooling cycle completes, the air conditioner makes a brief clicking sound, indicating that the motor and compressor are shutting down.

None of these noises should last very long or be extremely loud. If your air conditioner continues making worrisome noises, there may be a problem that requires professional repair. Here are the most common air conditioner noises and what they mean.

Screeching Noises

If you hear a screeching or squealing noise, there’s probably something wrong with the fan in the blower motor. The fan is responsible for pushing cooled air through your home, and loose parts or damaged motor bearings can cause the fan to squeal.

Squealing and screeching could also indicate that there’s a pressure problem inside the air conditioner. If there is too much pressure in the unit, it could catch on fire or even explode. This is unlikely to happen, but it’s not worth the risk. Stop using your noisy air conditioner and call a technician for repairs right away.

Banging Sounds

When you turn on the air conditioner, it makes a banging noise so loud that it causes you to jump in surprise. This is one of the most startling noises your unit can make, and it’s definitely a sign that something is amiss with the system.

Loose parts bouncing around in the unit can make a repetitive banging or rattling noise. For example, if a belt has come loose, you might hear it flapping around inside the air conditioner.

In the worst-case scenario, something may be wrong with the compressor, which is responsible for moving refrigerant around inside the system. Because compressors are difficult and expensive to repair, you might opt to replace the air conditioner instead.

Buzzing Sounds

We’ve already mentioned that a faulty air conditioner fan can make a squealing noise, but if your fan blades are loose, you might also hear a buzzing sound. That’s the sound of the blades bouncing off other components in the unit. You’ll need to have an HVAC technician check your noisy air conditioner for loose parts and missing screws.

A buzzing sound could also indicate a refrigerant leak. Refrigerant is a dangerous chemical that requires special training to handle, so if you think your unit is leaking, call a professional for repairs immediately.

Humming Noises

As we discussed above, it’s normal for your air conditioner to hum briefly when the compressor first kicks on. This noise is relatively quiet and shouldn’t last more than a minute or so.

If the humming is loud and persistent, there’s likely an issue with the contactor relay switch. This component tells your outdoor unit to turn on when it gets the signal from your thermostat.

In addition to a noisy AC, another telltale sign of a faulty contactor relay switch is that you won’t be able to turn the air conditioner on. Fixing contactor relay switches requires electrical expertise, so call a trained HVAC technician for help.

Gurgling and Bubbling

You might occasionally hear a soft bubbling noise from your unit due to moisture moving through the drainage line. If the gurgling never quits and seems excessively loud, though, you might have a refrigerant leak or a blocked drainage pipe.

It may be possible to remove the blockage from the drain line yourself if you’re comfortable working on the unit. However, you can damage the air conditioner if you’re unsure of what you’re doing. In most cases, it’s better to hire a professional to help you.

Clicking Sounds

Does your air conditioner make a clicking noise when it turns on and off? This is normal as long as the noise only lasts for a second. But if the clicking persists, there may be something wrong with your thermostat. For example, there could be an electrical problem that’s causing the thermostat to send an “on” or “off” signal to the unit over and over again.

Our technicians will inspect your thermostat and discuss your options for repair or replacement.

Vibration Sounds From the Vents

Hear a vibrating or rattling noise from the vents when your air conditioner kicks on? The most likely cause is that your vents are blocked. This can happen if you go too long between air filter replacements, causing debris like dust, pet hair, and cobwebs to build up in the vents.

Luckily, compared to other AC problems, this one is an easy fix. Give your vents and air ducts a good cleaning, and replace the filter if it’s dirty.

Got a Noisy Air Conditioner? Call Our HVAC Experts in Louisville for Repairs

If your AC won’t power up or it’s making a terrible racket, reach out to our experts at A1 Mechanical. We offer everything you’re looking for in an HVAC company: fast repairs, great prices, and experienced technicians. Call (502) 708-2247 to schedule service today.