Why Is My Air Conditioner Making Noise Even When Its Off?

Most people expect their air conditioners to make some noise when it’s running. But if a buzzing type of sound persists even after your air conditioning shuts down, it might be because something isn’t working right. Whether it’s a faulty motor or an erratic electrical connection, it’s worth looking into. Otherwise, your air conditioner may stop working altogether. 

Calling a professional technician is the best idea when your air conditioner is making noise, since they can quickly determine the source and begin repairs. In the meantime, here’s some useful information about why your air conditioner might be noisy. 

First, Find Where the Sound is Coming From 

Tracing the sound back to the source can help the technician narrow down the possible causes. Your central air conditioning system consists of two units. The outdoor unit disperses the heat collected from your home and cools it down with the refrigerant. This cooler air is sent to the indoor air handler, which makes sure the conditioned air is sent into the ductwork. If the noise you’re hearing isn’t coming from either of these units, the problem can be located inside the ductwork itself. 

If the sound is coming from the indoor unit: When noises are coming from the indoor unit, it can often be because there’s something wrong with the blower motor. A faulty electrical connection could cause the motor to make a buzzing sound regardless of if the air conditioner is on. 

Sometimes, however, the noise comes from your condensate pump. This component helps drain excess moisture away from the rest of the AC system. It may continue to run after a cooling cycle is complete if there’s still moisture that needs to be removed. 

If the sound is coming from the outdoor unit: Just like the indoor unit, the outdoor unit uses a fan and motor. But instead of sending cool air into your ductwork, this fan is used to dissipate the heat collected from indoors. A damaged connection could produce a similar buzzing sound, and since it’s outdoors, it could be a while before you notice it. 

The outdoor unit also houses the relay switch, an important component for controlling the voltage that enters the system. When this part makes a sound, it might have failed and will have to be replaced. 

There’s always a chance that a screw has shaken loose or a piece of debris has gotten wedged somewhere inside the system. This can happen to both the indoor and outdoor unit, and will produce a variety of noises depending on where the object is lodged. If this is the source of the annoying sound, you shouldn’t hear it for much longer after the AC shuts off. To make noise in the first place, it’d have to be close enough to something that could cause it to rattle against the unit housing. 

These Noises Are Most Often Because of an Electrical Problem 

You may have discovered that a lot of the possible causes of this unusual noise have something to do with electrical components or the connections themselves. Since these components won’t work without power, a malfunctioning electrical part is the most likely reason you’ll hear something even when the air conditioner is off. After your technician has identified where the sound is coming from, they’ll typically start checking components such as the relay switch and compressor, as well as all connections. 

Even if you’ve found the source of your problem and think it’s a simple fix, it’s best to let a licensed and insured professional resolve electrical problems. 

Leave Electrical Problems to the Pros 

If your air conditioner’s electrical system is malfunctioning or damaged, hiring a professional is the right move. There are several reasons why: 

  • Electrical problems can be hazardous: Service technicians have the training, licenses and insurance for safe and effective solutions to electrical malfunctions. 
  • Improper repairs can end up doing more damage: Even if you think your DIY skills resolved the problem, it may have ended up doing more harm than good. Air conditioning systems are still complex machinery, after all. 
  • Pros can spot other problems: Technicians with extensive experience are more likely to notice when something else is plaguing your HVAC system. They can handle it right there instead of letting the issue grow or worsen. 

Other Common AC Noises 

Getting familiar with a few other noises that could come from your air conditioner is a great idea. The next time something is wrong, you may be able to recognize it more quickly and call for professional service. A few other unusual noises include: 

  1. Trickling or Hissing: A leak is the most common culprit. Air leaks are inefficient but can be simpler to resolve. If the coolant is leaking, however, that may spell big trouble. Components related to the refrigerant supply are costly to fix and could end up resulting in having to replace the air conditioner entirely. 
  1. Clicking or Ticking: When running normally, you’ll hear clicks as electrical components start up and direct the air conditioning to run. When there’s an electrical problem, these clicking sounds can happen at random. 
  1. Clanging or Rattling: These sounds are often because of a loose screw or a piece of debris. But sometimes it’s a piece of a more important component like the compressor. The compressor is airtight, so if something breaks off inside it, you could be stuck with an unpleasant rattle until it’s fixed. 

Call Service Experts Heating, Air Conditioning & Plumbing for Quiet, Comfortable Cooling 

If something doesn’t sound right, don’t wait and see if it goes away by itself. The faster a professional technician can start repairs, the quicker things can be resolved. You’ll enjoy a quieter air conditioner and efficient cooling. 

Request an appointment with the HVAC pros at Service Experts Heating, Air Conditioning & Plumbing today by giving us a call at 866-397-3787. 

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